Cats admire many for their gracefulness, flexibility and piercing eyes. “Cats have 9 lives,” we used to say. Largely due to their body structure, they do things that other animals are not capable of.

Features of the structure of cats

Cats became pets much later than dogs. Therefore, they retained the body structure characteristic of all representatives of the feline family. The length of the body of a domestic cat varies within 60 cm, and the length of the tail is 25–30 cm. The average weight of a cat is 2.5–6.5 kg, but there are also impressive specimens of 7–9 kg. Siberian and Maine Coon cats can weigh 11-13 kg. There were cases when cats reached 20 kg, but most often the reason for this was obesity.

On average, cats weigh up to 6.5 kg, but Maine Coons and Siberians can reach a weight of 13 kg

There are 4 parts of a cat's body:

1. Head. It distinguishes between the brain (cat's skull) and facial (muzzle) parts. The front part also includes the forehead, nose, ears, teeth.
2. Neck. The upper part and the lower area are highlighted here.
3. The torso. It is represented by the withers (it is formed by the first five thoracic vertebrae and the upper edges of the scapula, which are at the same level with them), back, lower back, thoracic region (chest), croup, groin, abdomen, mammary glands and prepuce, anal region, tail.
4. Extremities. Thoracic (front): shoulder, elbow, forearm, wrist, metacarpus and pelvic (back): thigh, knee, lower leg, heel, metatarsus.

The structure of the skeleton of a cat and its joints

The skeleton plays the role of a skeleton of bones (there are about 240 of them in a cat) and has 2 sections: axial and peripheral.

The skeleton of a cat has about 240 bones

The axial section includes:

The peripheral section includes the front and hind limbs.

We all know that cats walk on their toes without stepping on the heel completely. This is because the knee is higher than we usually think - near the abdomen.

On each of the front paws there are 5 fingers, on the hind paws - 4. Each finger ends with a sharp claw, in a calm state hidden in a so-called pouch.

The cat releases its claws only when necessary.

Cat's joints are divided into:

• the seams that form between the fused bones of the skull and consist of hard fibers, immobilized;
• cartilaginous, which consist of strong cartilage, in a cat these joints are more flexible and mobile than in other animals;
• synovial - these are connections between two or more bones, providing them with great mobility, the main types of such connections:
  • ball,
  • articulated.

Video: cat skeleton

Muscular system

Cats have an unusually developed muscular system. This is proved by their amazing jumps for quite long distances and fast running. Also, a set of muscles helps the cat to keep its aristocratic bearing.

Thanks to the developed muscular system, the cat is able to perform amazing movements

In total, a cat has about 500 muscles. They can be divided into 3 categories:

• heart muscle;
• smooth muscles that control internal organs and work involuntarily;
• striated muscles that the cat controls itself.

Special fibers are found in all muscles. There are 3 types of cells in the muscles of a cat:

The structure of the shoulder girdle has a peculiarity: the muscles connect the forelimbs and the trunk, while in humans they are connected by the collarbone. In cats, it is in its infancy.

To make a step, the cat pushes off with its hind legs, and the front paws are involved in the braking process. Thanks to the elasticity of the back muscles, the cat can easily curl into a ball and take other bizarre poses.

Leather and wool

The skin and coat protect the cat's body from external influences: microbes, overheating and hypothermia.

Cat's skin performs protects the body from harmful environmental influences

There are two main layers in a cat's skin:

1. The epidermis is the top layer of the skin.
2. The dermis, which contains blood capillaries, hair follicles, nerve endings that transmit signals, and sebaceous glands that respond to nerve signals. Each hair follicle has its own sebaceous gland, which produces sebum that makes the coat shine. Special sebaceous glands are located in the anus and between the fingers, they produce pheromones. The sebaceous glands located on the muzzle serve the cat in order to mark the territory.

Cat hair has special cells called cuticular cells. They reflect light, giving the coat a healthy sheen. Therefore, dull hair in an animal always speaks of problems in the body. The hair follicle has an erector muscle that can lift the hair of the animal, for example, in case of severe fear or hypothermia.

Hair in cats is lifted by the erector muscle

Cat hair has a tactile function. Whiskers located on the face, throat and forelegs of cats are called vibrissae. They are clearly visible on the body of the animal. There are also small hairs - triloties, which are scattered on the surface of the animal's body.

Respiratory system

Breathing provides oxygen to the body and also gets rid of excess water.

The respiratory system of a cat is similar to that of most mammals.

Respiratory organs include:

The breathing process of a cat itself can be described as follows: under the action of the pectoral muscles and the diaphragm, the lungs expand and draw air through the nasal cavity into the respiratory tract until it reaches the alveoli, which are in contact with the blood vessels and saturate them with oxygen, at the same time removing carbon dioxide from them.

Circulatory system

The cat's circulatory system includes the heart and blood vessels that carry blood throughout the body:

• arteries - the vessels through which blood flows from the heart to the organs, they are saturated with oxygen;
• veins - the vessels through which blood flows from organs to the heart are saturated with carbon dioxide;
• capillaries are small vessels that ensure the exchange of substances between tissues and blood.

The heart is a special muscle that regulates the movement of blood through the vessels. A cat's heart weighs 16–32 g, it is four-chambered and has 2 halves, each of which has an atrium and a ventricle. The left side is responsible for arterial circulation, and the right for venous circulation. The systemic circulation originates in the left ventricle and passes into the right atrium. A small circle - from the right ventricle, which ends in the left atrium, then passes into the left ventricle, again starting a large circle.

Pulse - compression and weakening of blood vessels in time with the rhythm of heart contractions. On average, in cats, it reaches 130-140 beats per minute and can vary depending on the emotional and physical state of the cat.

You can feel the pulse of a cat on an artery located on the inner side of the thigh.

A cat has a peculiar composition of blood, and the blood of other mammals will not suit it. There are three blood groups: A, B, AB.

The liver and spleen produce blood cells. A large proportion of the composition of the blood is yellow plasma, 30-40% - erythrocytes, and the rest - leukocytes and platelets.

Digestive and excretory systems

The digestive system regulates food intake, absorption of nutrients and the elimination of undigested residues.

The organs of the digestive system are involved in the process of digesting food.

The digestion cycle is carried out in a day. This process involves:

• oral cavity;
• pharynx;
• esophagus;
• stomach - the Ph environment in the stomach is more acidic than in humans, which allows you to digest rough food and fight bacteria in the food;
• small intestine, in cats it is short and does not allow digesting carbohydrates well;
• colon;
• liver;
• kidneys.

The digestion process begins in the mouth as soon as food enters it. The salivary gland softens tough food, making it easier for it to enter the stomach and esophagus.

The process of digesting food begins in the mouth.

Under the influence of saliva, food begins to break down in the mouth. The complete food processing process takes place in 4 stages:

1. The fundus of the stomach contracts, pushing the contents towards the pylorus.
2. The contents of the stomach enter the duodenum in the following order: liquid, carbohydrates, proteins, fats.
3. Food passes through the small intestine where nutrients are absorbed.
4. The remains of food enter the large intestine, feces are formed and excreted.

A cat's stomach is constantly active. The cat usually eats often, but little by little (10-16 times).

Brain and endocrine system

Anatomically, the brain of a cat is similar to the brain of any mammal.

The structure of the cat's brain is similar to the brain of any of the mammals.

Different parts of the brain are responsible for a particular function in the body:

• the parietal lobe processes information received through the senses;
• the large brain is responsible for consciousness;
• the corpus callosum connects the right and left hemispheres;
• the frontal lobe is responsible for voluntary movements;
• the olfactory bulb is responsible for the perception of odors;
• the hypothalamus secretes hormones and controls the autonomic nervous system;
• the pituitary gland coordinates and controls the work of other glands;
• the spinal cord carries information from the brain to the body;
• the pineal gland is responsible for sleep and wakefulness;
• the cerebellum controls movements, muscle work;
• the temporal lobe is responsible for behavior and memory;
• the occipital lobe receives visual and tactile signals.

The endocrine system influences the basic functions of the body through hormones. Most hormones are secreted by the pituitary gland and hypothalamus. Some of them also produce the thyroid gland, adrenal glands, ovaries in cats, and testes in cats.

The endocrine system affects the basic functions of the body

Table: hormonal regulation of the cat's body functions

Hormone name	Where is it produced	Functions
Antidiuretic hormone (ADH)	Hypothalamus	Concentration of urine
Oxytocin	Hypothalamus	Labor and feeding of kittens
Corticoliberin	Hypothalamus	Concentration of adrenocorticotropic hormone
Adrenocorticotropic hormone (ACTH)	Hypothalamus	The adrenal glands produce cortisol if the cat is afraid
Thyroid stimulating hormone (TSH)	Pituitary	Thyroid activity
Melanocyte-stimulating hormone (MSH)	Pituitary	Synthesis of melatonin in the pineal gland
Follicle stimulating hormone (FSH)	Pituitary	Production of sex hormones and eggs in females
Luteinizing hormone (LH)	Pituitary	The production of sex hormones and sperm in males
Adrenalin	Adrenal glands	Cardiac activity and vasodilation
Progesterone	Ovaries	Preparation of the uterus for the introduction of embryos, preserving pregnancy, stimulating the development of mammary glands
Testosterone	Testicles, adrenal glands	The development of the reproductive system of the cat, the development of secondary sexual characteristics
Thyroxine	Thyroid	Increased metabolism, thickening of the walls of the uterus, increased heart rate

Nervous system

Cats have a particularly sensitive nervous system that controls the actions of the whole organism, which can be voluntary and involuntary. For example, during a hunt, an animal controls its muscles, preparing them for a jump or other action. The signal enters the brain, and from it goes to the muscles and the most accurate movement is obtained. Involuntary actions include breathing, swallowing, etc. They are regulated by the autonomic nervous system.

The nervous system of a cat consists of two types of cells:

Sense organs

With the help of the senses, the cat interacts with the outside world: it senses smells, touches, and tastes.

Vision

Cats have the largest eyes among pets. Developed peripheral vision helps the animal to notice small details and not to lose sight of prey. The cornea projecting strongly forward creates a large viewing angle of 250 degrees. It was also noted that animals are able to distinguish colors, however, a limited number - about 6.

Strongly protruding cornea creates a large viewing angle - 250 degrees

The sensitive pupil, expanding to its maximum size, allows the cat to see well in the dark. The pupil adapts to light, narrowing to a small vertical line.

Photo gallery: how cats compare to humans

Cats have a wider field of view, which is 250 degrees, compared to 180 degrees in humans Compared to humans, cats have much less visual acuity, which means that they are able to distinguish features at close range The vision of a cat is similar to that of color blind people: they see shades blue and green, but red can be indistinct and look like green, while purple is similar to shades of blue Cats do not see fine details and saturated colors, but they see 6-8 times better in the dark due to more rods - such as photoreceptors in the retina of the eye that are sensitive to dim light

Hearing

The hearing aid in cats is unusually developed. It is able to pick up vibrations of sound waves up to 65 kHz (the human ear picks up up to 20 kHz).

The main feature of the domestic cat's auricle is its mobility, which ensures perfect sorting of sounds.

A cat's ear consists of 3 parts:

• outer - that part of the ear that we see, its main function is collecting sounds and further transmission to the eardrum; asymmetric structure allows you to determine the location of the outgoing sound with maximum accuracy;
• middle, hidden in a bone pocket and consisting of three bones that transmit a sound signal from the membrane to the inner ear;
• the internal, reliably protected temporal bone, in which the organ of Corti is located, which converts sound vibrations into nerve impulses.

Smell

Cats can perceive 2 times more odors than humans. The main organ involved in the sense of smell is the nose. However, there is another special organ responsible for the perception of odors - the Jacobson organ, located on the upper palate and looking like a small tube 1 cm long. The cat rarely uses it: while catching the smell, the mouth opens slightly, as if attracting the smell to the palate.

Cats are able to perceive much more odors than humans.

A cat's nose has an individual fingerprint, like the pads of a person's finger. There are no animals with the same nose pattern.

Some odors can have a strong effect on the cat. For example, valerian or mint leaves the animal in a state of joy and euphoria.

Taste

Cats are able to distinguish between salty, sour and bitter tastes, but almost no sweet taste. About 250 special papillae located on the tongue and part of the pharynx help to receive taste sensations. Each of these papillae contains from 40 to 40 thousand taste buds.

Each of the papillae on the tongue has 40-40,000 taste buds

Touch

All over the body of a cat there are tactile hairs - vibrissae, or a more familiar name - whiskers. They interact with the nervous system and are located deeper than normal hair.

Vibrissae - the cat's guides in the tactile world

Reproductive system

The reproductive system is responsible for procreation.

The reproductive system of the cat

The female reproductive system includes the following organs:

• vulva;
• vagina;
• cervix;
• uterus;
• the fallopian tubes;
• ovaries.

The vulva and vagina (vagina), the organs involved in copulation, are also part of the birth canal.

A cat's ovaries enlarge at puberty.

The ovaries are the cat's genitals that produce the hormones estrogen and progesterone. Estrogen is needed for the development of the egg, and progesterone prepares the uterus for pregnancy. At puberty, a cat's ovaries enlarge. At about the age of 11-13 months, the first heat begins - an active readiness for mating. On average, it lasts a week and can be repeated every 3 weeks until pregnancy occurs.

The genitals of the cat provide the transfer of semen, containing sperm cells, and consist of:

In the testes, sperm are formed and testosterone is produced. Sperm are produced throughout a cat's life or until castration.

The production of testosterone affects the appearance of the cat: the head increases slightly compared to the body, and the body becomes athletic.

The cat's anatomical features make it an ideal predator. The skeleton, muscles and nerves provide the most accurate and fast movements, jumping and an amazing sense of balance. Sharp fangs help chew animal food. Sensitive hearing, sight and scent provide the cat with capturing the variety of external information. A cat is a pet that has a wild predator anatomy.

Bones and joints

Bones and muscles form, so to speak, the appearance of a cat's body, giving it its characteristic feline shape. When describing a kitten, we often say "long-legged" or "fat-footed", implying that its paws have proportions that differ from the proportions of an adult cat. Likewise, a kitten's body can be "round" or, conversely, "elongated". In any case, with these "terms" we are trying to describe the state of the skeleton of young animals in the process of formation.

A kitten is born with all the bones, joints, muscles, ligaments and tendons that an adult cat has. Its growth is due to an increase in the size of these organs, and not an increase in their number.

Bones, muscles, ligaments and tendons make up the bulk of a cat's body weight. Taking into account the different lengths of the tail, on average there are 244 bones in the skeleton of a cat.

Cat bones- rigid organs of complex structure, with their own feeding and blood vessels and nerves. Bones are made up of minerals, primarily calcium and phosphorus. Cat bones have many functions. They not only form the skeleton of the feline body, but also provide protection for many internal organs. For example, the bones of the skull protect the brain and eyes, while the sternum and ribs protect the heart and lungs. The bones of the limbs allow the cat to move. The bones of the inner ear do not function as protection or support, but rather to transmit sound, which allows the cat to hear. The soft cartilaginous tissue located in areas along the ends of the bones is called the articular ends, epiphyseal plates, or simply the pineal gland. The growth of the bone in length in kittens is due to the pineal gland. Growth usually continues throughout the year when bones reach their final length. At this time, the pineal gland becomes hard, saturated with calcium and other minerals, and loses its ability to grow. Young, not yet mineralized growth plates in kitten bones are often prone to bone injuries and fractures. Epiphyseal bone fractures in cats often occur in the wrist and knee area.

In mammals, there are 5 types of vertebrae. In a typical mammal - a cat, the number of vertebrae is as follows: the spine consists of 7 cervical vertebrae and 13 thoracic vertebrae. Attached to these vertebrae of the skeleton are 13 pairs of ribs that form the thorax, lumbar vertebrae - 7, sacral vertebrae - 3, caudal vertebrae up to 26 (depending on the length of the cat's tail).

The central nervous system of a cat (back and brain) is protected from damage by the entire system of the spine and skull.

The rib cage is formed by the ribs with the sternum and with the thoracic spines together. The first 9 pairs of ribs are directly connected to the sternum, the remaining 4 pairs of ribs are free, which form an arc.

Since a cat does not have collarbones (like other pets), the bones of the cat's forelimbs are connected to its rib cage by muscles and connective tissue. Cats, thanks to this, are able to squeeze their body through the smallest holes through which the cat's head can pass. An adult average cat can crawl into a 10 cm wide fence hole. Many have probably seen how a cat checks a hole, she first tries on her head to the hole through which she needs to crawl. This is determined by the specifics of the structure of the cat's limbs, which provides the animal with a springy landing when jumping.

The belt of the forelimbs of the cat - consists of the scapula, ulna, humerus and radius, as well as the bones of the paw and wrist.

The pelvic girdle of the cat's extremities - consists of the pelvis, thigh bone, tibia, patella, heel bone, and bones of the metatarsus with the phalanges of the fingers. Given the nature of the cat's movement (jumping), the links of the pelvic limb of the cat are more developed and longer than the links of the chest, and the metatarsal bones are about 2 times more massive and longer than the metacarpals. Cats can jump up to 5 times their height. The cat is a great acrobat. Both halves of a cat's body can move in opposite directions, and its front legs can rotate in either direction. The skinny forest cat will give odds to an ordinary apartment cat in terms of the volume of its brain, since there is a direct connection between the complexity of motor functions and the volume of the brain.

The cat has 9 toes on its feet - on the front 5 and on the back 4. Sickle-shaped sharp claws, with the help of the tendons of the muscles, can be extended and retracted. A cat's claws are modified skin: the translucent outer layer of the epidermis, made up of a dense protein called keratin, protects living tissue. The dermis contains blood vessels and nerve endings, so damage to the claws is extremely painful for a cat and care must be taken when cutting her claws.

On the wrist bones there are pads on which the cat steps on the lower surface of its fingers. In technical terminology, a cat's toes, together with their pads, are called “paws”. Like all mammals, cats bend elbows back and knees forward. What at first glance may seem like a bent back knee is actually the heel of cats with a long hind foot.

25 percent of cats and cats are ambidextrous (they have excellent control over both the left and right paws). Walking silently, the cat is provided with soft pads that are equipped with receptive nerves. In addition, they contain sweat glands, which can be easily detected when the animal is aroused. Then distinct beads of sweat appear on the pads, leaving marks on the floor.

Joints.Cat joints can be divided into three types: sutures, cartilaginous and synovial. They all have their own degree of mobility, and each of them performs its own functions.

The seams are formed between the fused bones of the skull and consist of hard fibers. They are generally devoid of mobility. For example, a cat's lower jaw is actually two fused bones connected between the incisors. If the cat hits the ground with its chin when falling from a height, the jaw may split. As a rule, in this case, it is not a fracture that occurs, but only a rupture of the fibrous tissue, that is, the suture connecting the two jaw bones diverges.

Cartilage joints are made of strong cartilage. In the cat, these compounds are more flexible and mobile than in other animals. They give the cat's body a special flexibility. An example of a cartilaginous joint is the thick discs between the vertebrae.

During the growth of the skeleton in kittens, the epiphyses at the ends of the long bones also consist of cartilaginous tissue; therefore, they are less durable and more susceptible to injury than the pineal glands in adult cats.

Synovial joints are the joints between two or more bones that give them greater mobility. The main types of such joints are ball and hinge joints. In these joints, the contacting surfaces of the bones, covered with smooth articular cartilage, are surrounded by a special capsule, the cavity of which is filled with synovial fluid. For example, very flexible leg joints have such a structure.

Skull and teeth... A feature of the cat's skull is approximately the same development of the facial and brain regions: the brain part consists of 11 bones, and the front part of 13. At first, the kitten's skull is made up of rigidly loose individual bones (this facilitates its appearance), and then these bones grow together with the formation of seams along the connection lines.
Like any predator, the cat has very powerful jaws. At the age of 3-4 weeks, the kitten erupts 26 sharp, like needles, milk teeth. The change of deciduous teeth by molars occurs at approximately 5-6 months.
An adult cat has 30 teeth, of which 12 incisors, 4 canines (sometimes also called predatory teeth), 10 premolars or premolars, and 4 molars or molars. A set of kitten's milk teeth are distinguished by the absence of molars. The correct bite for a cat is a straight pincer bite (the cutting surfaces of the incisors of the upper and lower jaws abut against each other like ticks). A deviation from the norm can be considered a gap between the cutting surfaces of the upper and lower incisors, exceeding 2 mm. An irregular bite, in which the lower incisors move forward, is called the pike jaw, and when the incisors of the upper jaw protrude forward in relation to the cutting surfaces of the lower incisors, such a bite is called overshot (catfish).
The cat uses the upper and lower incisors to capture prey, the canines, ideally suited to pierce between the cervical vertebrae of small rodents, hold and kill the prey, and the sharp and jagged premolars and molars tear and cut the meat. In the process of evolution, the upper molars in cats have practically disappeared, since the meat food of domestic cats does not need to be thoroughly chewed.

Muscular system

Muscle... The main function of the muscles is to provide movement for all parts of the cat's body. There are two types of muscle - striated and smooth. Smooth muscles are found in internal organs such as the intestines, stomach, and bladder. They are not controlled by the cat, functioning "on their own". Their work is automatically regulated in such a way as to meet the needs of the body. The striated muscles are predominantly attached to the skeleton. All their movements are under the conscious control of the cat. They provide movement of all parts of the body, allowing you to perform actions such as walking, eating, wagging the tail, turning the eyes, etc.

Tendons. Muscles are attached to bones by a tough, fibrous tissue called tendons. Tendons start at the muscle and end at the bone. A good example is the Achilles tendon, which connects the muscles of the lower hind limb (gastrocnemius) to the bone to form the ankles.

Ligaments and joints. Ligaments link bones together and are usually found in joints. A joint is where two bones meet, where the bones are covered with a smooth cartilaginous layer. The joint is made up of bones, muscles, ligaments, cartilage and lubricating joint fluid, enclosed in an articular capsule (bag).

Features of the shoulder of a cat. The shoulder girdle in cats is very peculiar. The forelimbs are connected to the trunk by muscles. In humans, the shoulder and sternum are connected by the collarbone. And in a cat, it is in free flight and is fixed only by muscles. That is why it is so easy for a cat to roll over on its paws during a fall and use a sliding step. Cats walk using their hind legs as a jerk. The front ones are used as a brake and shock absorber. During the run, the cat uses the following technique: transferring the left front leg simultaneously with the right hind leg, etc.

The elastic muscles of the back give the cat the ability to twist into a ball or twist the body when jumping. When attacking prey, the cat springs with its hind legs, arches its back and throws its front paws forward. The special development of the muscles on the wrists gives the cat agility in turning in different directions for hunting or climbing. The cat makes a jump up very accurately. The cat can estimate the distance of the distance and accurately match the force of the push of the hind legs to it. This jump is different from unplanned jumps during the pursuit. The extensor muscles of the paws work synchronously, and the cat jumps like a spring.

How well a cat can roll over in the air depends on its vision, vestibular apparatus, spinal mobility and muscle performance. When falling from a height of four to nine-storey buildings, cats often die. Because the speed of falling develops high and the force of impact with the ground is significant. An interesting phenomenon occurs when the cat falls from a higher place - the cat manages to take the most comfortable position to reduce speed. These are widely spaced paws and a head thrown upward.

The reflex that allows a cat to roll over in the air during free fall depends on a flexible spine, elastic musculature, keen eyesight and an excellent sense of balance.

Leather and wool

Leather... The skin and hair of a cat is a mirror of health. Wool and skin act as a buffer and protect the body from external influences (ultraviolet light, mechanical, chemical damage and microorganisms).

The top layer of the skin is called the epidermis. We can compare the structure of the epidermis with a brick wall, where cells (epithelial cells) are "bricks" and ceramides are "solution". With an optimal supply of fatty acids to the skin, a sufficient amount of ceramide substances is produced, and the "bricks" of cells are firmly held in the "wall". This ensures the barrier function of the skin, that is, the preservation of the internal environment of the body and protection from external influences.

There are two main layers in a cat's skin: the epidermis and the dermis. A strong elastic dermis is located under about 40 layers of dead cells (the epidermis itself) and 4 layers of living cells that make up the basal layer. In the thickness of the dermis are blood capillaries, hair follicles, nerve endings that conduct signals from the hair and skin, as well as special sebaceous glands that respond to nerve signals.
Each hair follicle has its own sebaceous gland, which produces sebum that makes the coat shine. Special sebaceous glands in the anus and between the toes produce sex pheromones. With the help of the sebaceous glands located on the muzzle, cats mark their territory.

Wool... The surface of the hair consists of overlapping cuticular cells that reflect light and give the coat its characteristic shine. Dull coat may indicate cuticle damage.

In cats, hair follicles have a complex structure: from each follicle up to six guard hairs grow, each of which is surrounded by thin fluffy (straight or wavy) hair. The follicle has its own lifter muscle, which makes the hair stand on end. Cats ruffle their fur not only when worried or frightened, but also in order to reduce the loss of heat in the cold.

A cat has two types of hair for touch. Whiskers, or vibrissae, are thick, coarse hairs on the head, throat, and forepaws. Large single hairs (tylotrichs) are scattered throughout the skin and function as a kind of short mustache.

Breathing and circulation

Respiratory system... The respiratory system of a cat is designed in such a way that it can function well in a variety of environmental conditions. The task of these organs is to ensure gas exchange and delivery of oxygen to the tissues of the body. They also serve to some extent as excretory organs, since through them excess moisture and harmful gases are removed from the body, and participate in heat exchange, because they remove excess heat from tissues.

The respiratory system of a cat consists of the nose, nasopharynx, larynx, trachea, bronchi and lungs. The lungs of cats are the main organ of their respiratory system. This is a paired organ, consisting of 2 lobes (right and left), which occupy most of the chest, like all warm-blooded animals. They consist of alveoli - pulmonary vesicles, tightly braided with a mesh of capillaries, which serve as conductors for gas exchange. The respiratory organs are covered with a mucous membrane, which performs the function of their protection.

In the process of breathing through the nose, air enters the larynx, from there - into the bronchi and lungs. This is associated with the normal functioning of the circulatory system. Also, breathing helps to normalize heat exchange and remove excess fluid from the body.

Circulatory system... There are no particular differences from the circulatory systems of most mammals in cats. A cat's pulse can be measured by pressing on the femoral artery located on the inner thigh. In a normal state, the pulse of a cat is 100-150 beats per minute. And in kittens, the pulse, as well as the temperature, and the respiratory rate, are much higher than in adult animals.

As the heart pushes blood through the arteries, their elastic walls actively contract and relax. This is called the pulse. Veins have thinner walls than arteries and are therefore more susceptible to damage. There is no pulse in the veins, but the blood flows through them strictly in one direction - to the heart - due to the valves in the veins.

Different parts of the body need different amounts of blood. For example, the brain accounts for only a small part of the body's weight, but it requires 15-20% of all blood contained in the body. Muscles at rest consume about 40% of the blood, and during physical activity (chasing prey, fleeing an opponent or enemy), up to 90% of all blood can circulate in them, that is, blood can be directed to muscles even from the brain.

The arteries carry bright red blood from the heart throughout the body, enriched with oxygen in the lungs and nutrients in the digestive system. Veins carry darker blood saturated with carbon dioxide to the lungs, liver and kidneys.

The exception is the pulmonary artery and pulmonary vein. The pulmonary arteries and their capillaries carry oxygenated blood to the pulmonary alveoli, where oxygen is absorbed from the air inhaled by the cat. The pulmonary veins return fresh blood to the heart, which pumps it through arteries throughout the body. Oxygen enters cells in exchange for carbon dioxide, and veins carry waste blood to the heart to pump it back into the lungs for oxygenation.

A heart... The main organ of the circulatory system is the heart - a hollow muscular organ that is located inside the chest, behind the median sternum. The weight of a cat's heart is directly proportional to the weight of the animal's body. In each case, this is approximately 0.6% of the body weight. A cat's heart consists of 2 atria and 2 ventricles.

The cat has 2 circles of blood circulation. Blood circulation is carried out along the arteries going from the heart to the capillaries, which permeate all internal tissues and organs. There, metabolism takes place, then the blood, saturated with carbon dioxide and containing the waste products of the body, enters the veins leading to the heart. Veins form a second, or small, circle of blood circulation. Venous blood enters the right ventricle of the heart, then through the pulmonary arteries into the lungs.

Brain and endocrine system

Cat brain consumes 20% of the blood distilled by the heart Hormones regulate the physiological functions of the body and behavior. Cats don't just live by instincts - they are quite trainable.

All the senses and hormone-producing glands transmit information to the brain. The brain processes chemical signals and sends commands to the body through the nervous system. The brain requires a significant expenditure of energy, and although the brain weighs less than 1% of the body weight, it receives 20% of the blood distilled by the heart.

Regulation of physiological functions... Hormones produced by the brain regulate most of the body's functions. Antidiuretic hormone (ADH) is produced by the hypothalamus and regulates urine concentration. The hypothalamus also produces oxytocin, which stimulates the process of labor and milk production in cats, and corticoliberin, which regulates the release of adrenocorticotropic hormone. Adrenocorticotropic hormone (ACTH) causes the adrenal glands to release cortisol in response to stress or danger.

Growth hormones: The pituitary gland produces hormones that regulate the release of growth hormones. Thyroid stimulating hormone (TSH) stimulates the thyroid gland, which in turn controls the metabolic rate. Melanocyte-stimulating hormone (MSH) accelerates the synthesis of melatonin in the pineal gland. Melatonin is involved in the regulation of the sleep-wake cycle, maintaining the 24-hour rhythm of the cat's life.

The production of sex hormones, eggs and sperm is controlled by follicle stimulating hormone (FSH) in cats and luteinizing hormone (LH) in cats.

Adrenal glands. The adrenal glands are located next to the kidneys and are made up of the cortex and internal medulla. The adrenal cortex produces cortisol and other hormones that play an important role in regulating metabolism and shaping the body's response to injury. The adrenal medulla produces epinephrine and norepinephrine (better known as adrenaline and norepinephrine).

These hormones control heart rate and vasodilation. The adrenal glands are a vital link in the biofeedback system that controls the fight-or-flight response and directly influences the cat's behavior. Feedback mechanisms determine the mood of cats, their sociability and "tameness".

Biological computer. The cat's brain is made up of billions of special cells called neurons. Each of them has up to 10,000 connections with other cells. in a seven-week-old kitten, messages are transmitted in the brain at a speed of almost 386 km / h. The transmission rate decreases with age.

Anatomically, the brain of a cat is similar to that of any other mammal. The cerebellum controls muscles, the cerebral hemispheres are responsible for learning, emotions and behavior, and the trunk connects them to the peripheral nervous system. In the limbic system, it is believed that there is a connection of innate information with assimilated data.

The intelligence of a cat. Cats have an innate instinct to mark and defend territory and to hunt, but they still need to learn how to do it all.

By raising kittens, we actively interfere with the development of their brains and the formation of behavioral mechanisms. A cat that entered the human family before she was seven weeks old learns to trust people, while street cats tend to be suspicious of other animals and people: after all, cats are small and relatively defenseless against such opponents.

Some people think that nothing can be taught to a cat. Cats may indeed seem like animals that defy learning, because their brains are adapted for a solitary lifestyle and they hardly master the social skills that we and other herd animals use instinctively.

As a rule, praise cannot force a cat to obey, because from the point of view of a lone hunter, the approval of others does not affect survival in any way, but the cat can compromise for food rewards.

A prime example of a feline “mindset” is a cat that desperately resists pushing it into a veterinarian bag and happily climbs into it to return home. A "smart" animal can perfectly choose the lesser of two evils ..

Nervous system

Nervous system... In the nervous system of cats, electrical impulses are transmitted along nerve fibers, giving commands to the corresponding organs. For communication between nerve cells of various organs for their coordination, chemical processes are also used. The cat's nervous system is a very complex network.

Central nervous system: In mammals, the nervous system consists of several segments. The central nervous system includes the brain, brain stem, and spinal cord. The peripheral nervous system includes the nerves that exit the brain to the head and neck region, as well as the nerves that enter and exit the spinal cord. These nerves transmit signals from the central nervous system to other organs in the body, such as the legs and tail. Nerve impulses from the brain pass through the spinal cord and peripheral nerves, into the tissues of the cat's body and return back in the same way, communicating information from all parts of the body to the brain.

Peripheral nervous system: Peripheral nerves that emerge from the brain and spinal cord are called motor nerves. These nerves control muscles to allow movement, posture, and reflex responses. The peripheral nerves that transmit signals to the brain and spinal cord are called sensory nerves. They carry information (such as the feeling of pain) from the organs of the body to the central nervous system.

Autonomic nervous system: Other groups of nerves form the autonomic (autonomic) nervous system. The autonomic nervous system contains nerves that control involuntary movements of organs such as the intestines, heart, blood vessels, bladder, etc. The cat cannot consciously control the organs through the autonomic nervous system, they function "automatically".

Coordination of movements: At birth, the nervous system of kittens is not yet fully formed. The brain, spinal cord and associated nerves are present at birth, but do not have the ability to adequately and in a coordinated manner transmit electrical impulses. As the nervous system develops in the first weeks of life, the number and duration of conscious, controlled movements increase significantly. In the first week of life, the kitten is not capable of much, he only sleeps and eats. Some erratic physical activity is observed even when the kitten seems to be fast asleep. In the second week of life, the kitten still spends a lot of time sleeping, but the sleep becomes calmer, with fewer involuntary movements. When they wake up, kittens tend to feed. By the end of the third week, most kittens can maintain an upright position for quite a long time and spend much more time awake. Kittens try to move by raking with their paws, as they cannot yet fully stand and walk. The first attempts at walking are usually short, as the muscles do not yet have sufficient strength. After three weeks, kittens can stand and walk short distances. Over the next few weeks, the kitten becomes quite mobile, can walk and even run, albeit somewhat awkwardly.

Vision: Kittens are born with their eyelids closed. By two weeks, the eyes open, but the eyeball has only a low sensitivity to light. By three to four weeks, kittens already have vision, but it is fully formed only after ten weeks of life.

Hearing: Kittens are born deaf. Like the eyelids, the auditory canals remain closed until about two weeks of age. At two weeks, most kittens can distinguish some noises. By this time, they are already afraid of harsh sounds. By the age of four weeks, the sounds no longer frighten the kittens, the hearing is fully formed.

All of the above abilities - movement, hearing and vision - are provided by the cat's nervous system. The dates mentioned are average - the exact age at which these abilities fully develop is, of course, impossible to indicate.

Diseases of the nervous system can occur as a result of abnormal development of nerve tissue and associated organs, or from damage due to trauma or infectious diseases. Many diseases of the nervous system of cats are of genetic origin.

Nerve cells... The nervous system consists of nerve cells, neurons and their supporting cells, which produce myelin.
Branches - dendrites - branch off from the body of the neuron, which receive information from other cells. Each cell also has one long process - the axon, which sends messages to other nerve cells or directly to organs. All of these messages are carried by neurotransmitters, or transmitters - chemicals produced in axons. The cat's nervous system is constantly transmitting and receiving a huge amount of messages. Each cell sends messages to thousands of other cells.

Myelin is a fatty protective membrane that covers the largest axons and increases the speed of communication between nerves. The nerve fiber consists of an axon, myelin sheath, and a cell that produces myelin.
Myelin is produced in the central nervous system by cells called oligodendrocytes, and in the peripheral nervous system, neurolemmocytes. Few nerves are myelinated at birth, but in kittens the nerves are myelinated quickly and very efficiently.

Sense organs

Vision... If you compare a cat with other pets, you will notice that it has the largest eyes in relation to body size.

For a long time, scientists have noticed a unique feature of the cat - binocular (stereoscopic) vision. This property is determined by the unusual location of the eyes: they are located in front, on either side of the nose, and the animal has the opportunity to view objects of interest at an angle of 205 ° in the same direction while simultaneously crossing the field of view at the central point. This property allows cats to accurately determine the distance to an object. In addition, with such an arrangement of the eyes, the animal gets the opportunity to see what is located not only directly in front of him, but also on both sides.

The iris that surrounds the pupil of the cat's eye has the same mobility as in all members of the mammalian class. It is set in motion by muscles connected to the eyeball.

Due to this property of the iris of the eye, in bright natural or artificial lighting, the pupil of the cat's eye is extended vertically and takes an ellipse shape. This protects the animal's eye from the penetration of more light into it than is necessary for the perception of the surrounding world.

Due to the peculiarities of the structure of the eyes, cats can see in the dark. It is a misconception that cats see perfectly in the dark due to the fact that their eyes can glow. The reason cat eyes glow in the dark is because they have the ability to accumulate reflected light rays.

With the help of perfectly developed vision, the cat catches the reflection from objects of even the weakest ray of light entering the room where it is located, and, thanks to this, orientates itself in space. But in absolute darkness the animal, of course, cannot see.

Cat pupils expand and become completely round when a lot of light enters the eyes. If a cat's pupil remains dilated in light, it may be due to agitation, medication, or a symptom of a medical condition.

Representatives of the feline family have another feature of the structure of the eyes - the so-called third eyelid, or blinking membrane, the function of which is to protect the cornea of ​​the eye from foreign bodies, such as dust, from entering it. This is possible because the third eyelid is able to stretch and cover the entire surface of the eye. Although the third eyelid is protective, it is prone to inflammation and very susceptible to infection. The owner of the cat should be aware of this and not neglect the rules of hygiene when caring for the eyes of his animal, since in some diseases the loss of the third century is observed.

Hearing in cats unique. They are able to distinguish more than 100 different sounds, For comparison: the human ear does not perceive even half of these sounds.

A cat has a wide hearing range, from 30 hertz to 45 kilohertz. It perceives high frequencies better than a person: the human ear distinguishes sound up to a frequency of 20 kilohertz, and the feline ear perceives sounds up to 75 kilohertz. However, white blue-eyed cats are often completely deaf. This is due to the genes that appear in the combination of white wool and blue eyes.

The ears of cats are erect and located on the sides of the top of the head. Almost every breed of dog has its own shape of ears, but in cats there is not much difference (only in Scottish Fold cats, ears have a characteristic shape). Only small differences in the size of the pinna can be noted: the largest ears are in Siamese and Oriental cats, and the smallest in Persian.

Like other animals, a cat can wiggle its ears. For this she has 27 special muscles. It is easy to see that the cat turns its ears in the direction from which the sound is coming. Perfectly developed hearing can also explain the well-known fact that cats, even at a great distance from their home, can orient themselves well and find their way in the opposite direction.

Smell... By smell, the cat finds food, detects danger and distinguishes friends from enemies, and also "reads" chemical messages in excrement. Cats have a weaker sense of smell than most carnivorous animals, but much stronger than humans (since there are twice as many receptors sensitive to odors in a cat's nose than in a human one).

In the nasal cavity, molecules of odorous substances are sorbed by sticky membranes lining the curved bones - the turbinates.

In the upper palate is the vomeronasal organ, also called the Jacobson organ or the Jacobson organ. Highly sensitive to airborne substances, the vomeronasal organ is a small tube about 1 cm long with an entrance to the oral cavity behind the upper incisors. He perceives both smell and taste at the same time.
When a cat uses this organ, it lets the inhaled air pass through the upper palate. At the same time, her mouth opens slightly, her lip rises slightly, and her upper teeth are exposed. From the outside, it resembles a grin, which is why the phenomenon was called Flemen's smile or Flemen's smile.

The organs of taste in a cat distinguish between sour, salty, sweet and. bitter substances. Cats recognize bitter and salty substances well and, worse, sweet ones. This, but most likely, is due to the fact that the live prey of the wild ancestors of the domestic cat had a bitter and salty taste of blood and meat.

The tongue of a cat, like ours, is covered with taste buds. And the cat is exceptionally picky about the taste and texture of the food offered to her. She is the most meticulous customer in the animal feed industry. Typically, a cat is offered 10 flavors, of which she, having tried, recognizes (if at all) usually two or three varieties.

On the upper side of the tongue there are small horny hooks, which are perceived by human skin as rough sandpaper. Licking with this rasp tongue will turn our skin red after just a few touches. Horn hooks clean and lick the cat's hair, helping the cat to cope with a large piece of meat by scraping off individual fibers.

The cat licks the water not with a flat tongue, but gives it the shape of a small groove and quickly captures the liquid and sends it into the mouth.

Touch cats are well developed. The cat receives most of the information about the world through the corresponding organs. In addition to tactile hairs located on the head and paws, this animal can sense the surrounding space with the entire surface of the body.

Paw pads in cats have a special structure. Because of this, cats really do not like to step on a dirty or wet surface, after which they always shake their paws, which is explained not only by the well-known cleanliness of these animals, but also by the extreme sensitivity of the paw pads.

Unlike dogs, who get acquainted with an object of interest with the help of smell, a characteristic feature of all representatives of the cat family is that they first touch an unfamiliar object with their paws and only then sniff.

Often the cat is the initiator of the fact that the owner takes her in his arms, caresses and strokes, while the animal blinks, purrs and looks very pleased. True, this only happens in cases where the owner strokes the cat in the direction of hair growth, and not vice versa. If you pet a cat against the coat, it is likely to get angry and scratch. This behavior is explained by the fact that the organs of touch in a cat are not located on the skin, but on the surface of special tactile hairs, which have increased sensitivity on the head and forepaws.

Digestive and excretory systems

Digestive system

Cat esophagus is a small tubular tube that connects the mouth to the stomach. Starting at the mouth, the esophagus passes through the neck and chest, near the heart, through the muscles of the diaphragm, and ends at the entrance to the stomach. The walls of the esophagus hold back muscles, which, making wave-like contractions, push food into the stomach. When there is no food in the esophagus, the walls are pressed against each other, closing the esophagus. Esophageal surgery is usually difficult as it is located in the chest and heals very slowly.

Cat stomach adapted to preserve a large amount of food and a long process of digestion. Food enters the stomach through the esophagus through a valve-shaped organ called the heart sphincter. There are a number of folds on the inside of the stomach. The function of the gastric folds is to help grind and digest food. The lining of the stomach secretes acid and enzymes that break down food. When pretreatment is complete, the partially digested food leaves the stomach through the pyloric sphincter and then enters the duodenum (the first segment of the small intestine). Eaten food mostly leaves the stomach within twelve hours after ingestion.
Small intestine of a cat.

Small intestine of a cat is a tubular organ located between the stomach and large intestine. It makes up the largest part of the intestinal tract and is two and a half times the total body length of a cat. In a cat that is 60 cm long, the small intestine will be one and a half meters long. The small intestine of a cat consists of three parts. The first part, located near the stomach, is the duodenum. The middle (and longest) part is called the jejunum. The shortest part is the ileum, which connects to the large intestine.

Duodenum connecting to the stomach is relatively short. However, it performs very important functions. The gallbladder and pancreas are connected to the duodenum and pancreas by the bile and pancreatic ducts, respectively. The enzymes produced in the liver and pancreas of the cat, as well as other substances important for digestion, enter through these ducts, mixing in the duodenum with food.

Jejunum- the middle section of the small intestine, after the duodenum and in front of the ileum, the longest section of the small intestine, covered with dense villi (villi). The villi sink into the food, providing a large surface area for nutrient absorption. From the jejunum, food enters the ileum, and from there into the large intestine.

Diseases of the small intestine, as a rule, are not limited to only one of its parts, and therefore are considered as disorders of the small intestine in general.
Large intestine of a cat.

Liver. The largest gland in a cat's body is the liver, where the blood delivers nutrients. The liver converts these nutrients into essential amino acids and fatty acids. Unlike humans or dogs, a cat requires animal protein to produce the full range of liver acids. Therefore, in order to maintain the vital activity of the cat, it is necessary to eat meat, otherwise it may die. The liver performs a barrier function, in other words, it promotes the breakdown of toxic substances and prevents the spread of viruses and bacteria. The liver is divided by the fibrinous membrane into left and right lobes, which are divided in turn into lateral and medial parts. In size, the left lateral lobe is much larger than the relatively small left medial lobe and covers with one end most of the ventral gastric surface.

The right medial lobe, in contrast to the left, is large, on the back side of it there is a gallbladder. At its base there is an elongated caudate lobe, on the right side of the anterior portion of which is the caudate process, and on the left - the papillary process. The liver performs one of the most important functions - the production of bile. The gallbladder is located in the cleft of the right medial lobe and is pear-shaped. The liver is supplied with blood through the hepatic arteries and the portal vein, and the venous outflow is carried out into the caudal vena cava through the hepatic veins.

Colon cat connects the small intestine and anus. The large intestine is larger in diameter than the small intestine. Its main function is to absorb water from feces as needed in order to keep the body's fluid content at a constant level. Another function of the large intestine is to temporarily store feces before it is expelled from the cat's body. The large intestine has several parts. The cecum continues the small intestine. Its true purpose is unknown. The colon is the longest part of the colon and only ends inside the anus. The final part of the large intestine is called the rectum.

Excretory system. The organs of the urinary system are responsible for the removal of excess fluid from the body: the bladder, kidneys and ureters. In them, the formation, accumulation and excretion of urine with the products of digestion and metabolism dissolved in it takes place, they also regulate the salt and water balance in the cat's body.
Urine production takes place in the kidneys, where the nephrons filter waste substances brought in from the liver. A cat produces up to 100 ml of urine every day. In addition, the kidneys regulate blood pressure, maintain the chemical balance of the blood, activate vitamin D and release the hormone erythropoietin, which stimulates the formation of red blood cells.
From the kidneys, urine enters the bladder through the ureters, where it accumulates until the next urination. Control of urination is carried out with the help of the guard muscle located in the bladder, which does not allow urine to be excreted spontaneously.
The urethra, through which the fluid accumulated in the bladder is removed to the outside, is short in cats and ends in the vagina, and in cats it is long, curved and ends at the head of the penis. A distinctive physiological feature of the urethra of cats is stenoses - special narrowings that serve for the rapid passage of urine containing sediment.

Breeding system

Cats are extremely temperamental, usually puberty in cats occurs at the age of 6-7 months, and in cats - at 10-12 months. By the age of one and a half, the physiological development of both sexes occurs in full. Sexually mature cats periodically have sexual heat, which can last 7-10 days and occur monthly. During these periods, the cat is ready for fertilization. Cats are ready to mate all the time.

Males and cats reach sexual maturity at the age of 5 to 9 months, and from this point on the reproductive system of the cat is constantly ready to perform its functions. Luteinizing hormone (LH), secreted by the pituitary gland, causes the testes to produce sperm and the male sex hormone testosterone. Sperm production occurs in the testes, in the convoluted tubules, and continues throughout life. Since sperm are produced best at a temperature slightly lower than body temperature, the testes are lowered into the scrotum. The sperm are stored in the epididymis until needed. Then they are sent along two spermatic cords to the prostate and bulbourethral glands. Here, sugar-rich liquid is added to them.

Castration of a cat- a relatively simple operation. Under general anesthesia, the testes are removed through a small incision in the scrotum. The spermatic cord and associated blood vessels are ligated. Usually, the operation is performed at the age of about six months.

Neutering a cat- a more serious abdominal operation. The ovaries and uterus are removed to the very cervix. Sterilization can be done before puberty.

Female hormones... Like most other domestic animals, a cat is in heat several times a year, but its reproductive system is most active during the period when the duration of the light part of the day increases.
At the end of winter, increased daylight hours stimulate the pituitary gland, which begins to produce follicle-stimulating hormone (FSH). FSH causes the ovaries to produce eggs and the female sex hormone estrogen. Estrogen is excreted in the urine, informing all neighboring cats that the cat is ready to mate.
Upon reaching maturity, which is at the same age in cats as in cats, all the eggs are already contained in the ovaries. However, unlike sexual
systems of most other mammals, the ovaries do not release these eggs until mating occurs.

Pairing. The cat will not allow the cat to mate with her until she is fully prepared for this. Finally she lets the cat, he grabs his teeth into her scruff and immediately mates with her. The cat's penis is covered with hooked spines that irritate the vagina at the end of mating. This stimulates the release of eggs.

In cats, ovulation occurs only after mating, which stimulates the release of eggs. Mating alone is often not enough for this. If mating does not occur during estrus, the eggs will not be released. In this case, after a certain period of time (from two days to two weeks), the cat begins a new estrus. Under the influence of artificial light, unsterilized domestic cats can be in heat throughout the year.

The article used materials:

• site www.farai.ru Cattery of Abyssinian cats "FARAI", Moscow
• site http://mainecoon-club.ru/ Club of friends of cats Maine Coon
• site http://www.zoocats.ru Cattery of British cats "Scarlet sails"
• site http://goldcoon.ru/ Maine Coon cattery "Golden Lion"
• site http://mypet.by/ myPet.by: Articles. Question answer. ads
• site http: // zoolife.com.ua/ Cats. Dogs. Pets
• site http://1001koshka.ru / 1001 cats. All about cats

The variety of unique physical capabilities of the cat is largely due to the skeleton. Lightning-fast tree climbing, balancing at high heights, crawling, various kinds of jumps and safe landings - all this is possible due to the peculiarities of the cat's anatomy and, in particular, the skeleton, so we suggest taking a closer look at its features and structure.

The general structure of the skeleton of a cat is similar to the structure of the skeleton of other mammals, with the exception of some differences in the shape and location of individual bones, which is associated with the horizontal position of the spine and maximum adaptability to the predator's lifestyle. In addition, differences in the shape and structure of individual bones may be due to breed characteristics. For example, Siamese have narrower and longer bones than Persian cats. From the photo below you can understand what a cat's skeleton looks like without taking into account the breeding characteristics.

The skeleton of a cat consists of an average of 244-250 bones. In some sources, the number 230-236 is mentioned, since some of the fused bones are considered as one whole. How many bones a cat has is affected by the length of the animal's tail, since it contains almost a tenth of all the bones of the cat's body (there are about 26 vertebrae in a "normal" tail).

Skull

Due to the smaller number of teeth in comparison with other predators, the cat's skull is characterized by a rounded shape. Its size will depend on belonging to a particular breed or other hereditary traits. Representatives of the Persian, exotic and Himalayan breeds belong to the brachycephalic - the owners of a shortened skull, which is why they have an abnormal structure of the palate, larynx and trachea. This explains the common problems in these breeds with impaired nasal breathing, snoring and poor exercise and heat tolerance.

The skull consists of 29 bones, while the medulla is formed from 11, and the front - from 13 bones. The bones of the cranium themselves are larger than the facial bones. Characteristic features also include large eye sockets, narrowly spaced canines, adapted for hunting small animals. The main attribute of a predator, which is a cat, is a powerful jaw, which is equipped with different types of teeth. They allow you to grab and hold resisting prey, bite off and grind food and, if necessary, defend.

Spine

The feline spine is incredibly flexible as it is formed from small movable bones. It is represented by many vertebrae, which are divided into several sections:

• Cervical - consists of the larger 7 vertebrae, which are responsible for the support and mobility of the head. Two of them with their own names - epistrophy (axial) and atlas - tend to rotate 180 °. They are connected by a thin process, therefore, they belong to the vulnerable spots of the cat: with blows and falls, there is a high risk of rupture of the connection, respectively, fracture of the cervical vertebrae and death.
• The thoracic region consists of 13 vertebrae, to which 12 pairs of rib bones are attached on both sides. Of these, the first 5 pairs are called true, since they are fastened to the sternum, and the remaining ones are fake, since they have the form of arcs.
• Lumbar - formed from the 7 largest vertebrae, the size of which increases as it approaches the tail. They have special projections on the sides on which the muscles and internal organs of the abdominal cavity are attached.
• Sacral region - unlike the ultra-flexible lumbar region, it is characterized by a rigid intervertebral connection of three accrete vertebrae. This need is due to the fact that the hind limbs are attached to this area, which bear the main load during the movement of the animal (especially jumping).
• Tail region - plays a key role in maintaining body balance when jumping or falling from a height. Strong muscle ligaments provide these animals with ideal "jumping", and the cartilaginous pads between the vertebrae - the possibility of various movements (bends and rotations). The number of caudal vertebrae varies depending on the breed, and in some breeds they may not be present at all.

Limb structure

In the skeleton of the limbs of the cat, two sections are distinguished:

• The forelimb (shoulder) belt, the peculiarity of which is the elastic fastening of the limbs, which is necessary for cats for safe jumps and a comfortable landing. It is represented by the scapula, humerus, radius and ulna (form the forearm), brush. The latter consists of the wrist, metacarpus and phalanges of the fingers, of which there are only 5 on the forelimbs.

Another unique feature of feline anatomy is the lack of a full collarbone. It is represented by two non-functional bones that are not attached to the shoulder joint, but are freely located inside the muscles. The shoulder blades are attached to the spine by muscles, ligaments and tendons, due to which the shoulders have practically no restrictions in movement.

Interesting! Due to the unique structure of the collarbone, a cat is able to crawl even into the narrowest holes if the animal's head crawls through there, since it is the latter that is the most voluminous, but not subject to deformation, part of the body.

• The hind limb girdle, which, unlike the shoulder girdle, is rigidly and motionlessly attached to the sacrum. It includes: the pelvic and femur, the patella, the tibia and fibula, the tarsal and metatarsal, to which the phalanges of the fingers are attached. The pelvic bones of the hind legs are longer and better developed than the front ones, and the metatarsal bones are more massive, which is associated with the peculiarities of the animal's movement (in particular, jumping). Due to this structure of the limbs, cats can quickly move in horizontal and vertical planes, so they are excellent dart frogs. The hind legs rest on the phalanges of 4 toes. Like other mammals, cats bend their elbows back and knees forward. The part of the paw that can be mistaken for a bent back knee is actually the heel, and the true knee is located in the lower abdomen of the animal.

The coat of domestic cats and cats may differ in color and quality. In cats, the coat is thicker and coarser, usually of a brighter color. On the neck and throat in long-haired breeds, it forms a "mane".

The cat also has coarser and longer tactile hairs - vibrissae. They do not fall out during molting, constantly growing and grinding at the ends. This type of hair is located on the skin in the form of a mustache to the right and left of the nasal and supraorbital openings, as well as near the paw pads of the thoracic extremities.

The claws are horny curved tips that cover the third, last, phalanges of the fingers. When the muscles contract, the claws can be drawn into the roller groove

When the muscle relaxes, the joint is pulled back and the claw is released.

All predators of the feline family, with the exception of the cheetah, retract their claws into a soft protective cover. The protective leather cover for claws is a very sensitive place on the body of a cat, and its injury is very painful. Unlike a dead human nail, every cat's claw has a thin nerve and a capillary that supplies the claw with blood. Therefore, when heaving or other mechanical damage, the claws bleed, and the animal experiences severe pain. When a wounded or bleeding claw is drawn in, the guard hole is usually damaged, the animal's paw begins to swell and become inflamed. The claw of the first toe of the front paws is not retracted. Kittens under the age of 1 month do not use the muscles that remove the claws. Therefore, babies' claws are constantly released. The claws of unborn kittens are kept in horn cases that protect the mother's insides from damage. One day after giving birth, the horny sheaths dry out and fall off.

Thus, it can be concluded that cat claws are very sensitive and constantly renewed. Therefore, there is no need to be alarmed if you see horny transparent cases in the form of claws on the floor about half a centimeter in size. This is the dead top layer of the claw, under which there is a new one.

Crumbs are areas of the limbs that perform a supporting function. In addition, they are organs of touch. The cushion is formed by the subcutaneous layer of the skin. The paws of cats are pigmented and contain sweat glands, which can be easily seen when the animal is agitated. In this case, distinct beads of sweat appear on the surface of the pads, leaving marks on the floor. A cat has 6 crumbs on each thoracic limb, and 5 on each pelvic limb.

On the underside of the paws, at the level of the 2nd and 3rd phalanges, there are 4 narrow, oval pads of the fingers, and above there is one more pad, palatine, it is somewhat larger and has the shape of a heart.

All pads are soft to the touch, their surface is slightly wrinkled. The presence of such pads allows the cat to move almost silently. There is a pad on the thoracic limb, which belongs to the separately growing first toe. It does not carry any functional load.

The nervous system of a cat

The structural and functional unit of the nervous system is a nerve cell - a neurocyte. Each nerve cell has several sensitive, tree-like branching dendrites, which conduct excitation to the body of a sensitive neuron that occurs on their sensitive nerve endings located in organs, and one motor axon, along which a nerve impulse is transmitted from a neuron to a working organ or another neuron. Neurons come into contact with each other using the endings of the processes, forming reflex circuits along which nerve impulses are transmitted (propagated).

The processes of nerve cells, together with neuroglial cells, form nerve fibers. These fibers in the brain and spinal cord make up the bulk of the white matter. From the processes of nerve cells, bundles are formed, from the groups dressed in a common sheath, nerves are formed in the form of cord-like formations. Nerves vary in length and thickness.

Nerve fibers are divided into sensitive - afferent, transmitting a nerve impulse from the receptor to the central part of the nervous system, and effector, conducting an impulse from the central part of the nervous system to the innervated organ.

There are nerve ganglia - groups of nerve cells of the central part of the nervous system, isolated to the periphery. They play the role of a step-down transformer, as well as an accelerator for the conduction of nerve impulses in the affector sensitive ganglia and inhibiting in the effector nodes of the internal organs. The nerve ganglion is a multiplication site where an impulse can be propagated from one fiber to a large number of neurocytes. And the nerve plexuses are places where there is an exchange between nerves, bundles or fibers designed to redistribute nerve fibers in complex connections in different segments of the spinal cord and brain.

Anatomically, the nervous system is divided into the central, including the brain and spinal cord with spinal ganglia; peripheral, consisting of cranial and spinal nerves connecting the central nervous system with receptors and effector apparatus of various organs.

central nervous system

Brain

The brain is the head of the central nervous system located in the cranial cavity. Cats, like all mammals, have two hemispheres separated by a furrow. They are covered with a crust, or bark.

The brain is the highest part of the nervous system that controls the activity of the whole organism. It unites and coordinates the functions of all internal organs and systems. This is where the synthesis and analysis of information coming from the sense organs, internal organs, and muscles takes place. Almost all parts of the brain are involved in the regulation of autonomic functions (metabolism, blood circulation, respiration, digestion). For example, in the medulla oblongata are the centers of respiration and blood circulation. The main department that regulates metabolism is the hypothalamus, the cerebellum coordinates voluntary movements, ensures the balance of the body in space. In pathology (trauma, swelling, inflammation), the functions of the entire brain are impaired.

The volume of the brain of a domestic cat is less than that of its closest relatives - steppe and forest, which is the result of domestication. The same happens with all other pets.

Spinal cord

The spinal cord is part of the central nervous system, which is an accumulation of brain tissue with remnants of the cerebral cavity. It starts from the oblong part of the brain and ends in the region of the 7th lumbar vertebra. The spinal cord is conventionally divided into the cervical, thoracic and lumbosacral regions, consisting of gray and white medulla. A number of somatic nerve centers that carry out various unconditioned reflexes are located in the gray matter.

The white medulla consists of myelin fibers and is located around the gray in the form of three pairs of cords (bundles), which contain pathways from the spinal cord's own reflex apparatus, ascending paths to the brain (sensory) and descending from it (motor).

The spinal cord is covered with three membranes: hard, arachnoid and soft, between which there are cavities filled with cerebrospinal fluid. In cats, the length of the spinal cord is on average 40 cm, its mass is 8-9 g, which is 30% of the mass of the brain.

Peripheral nervous system

The peripheral nervous system is a topographically separated part of the unified nervous system, which is located outside the brain and spinal cord. It includes the cranial and spinal nerves with their roots, plexuses, ganglia and nerve endings embedded in organs and tissues. So, 31 pairs of peripheral nerves depart from the spinal cord, and 12 pairs from the brain.

In the peripheral nervous system, it is customary to distinguish three parts - somatic (connecting centers with skeletal muscles), sympathetic (associated with smooth muscles of the vessels of the body and internal organs), visceral, or parasympathetic (associated with smooth muscles and glands of internal organs), and trophic (innervating connective tissue).

Autonomic (autonomic) nervous system

The autonomic nervous system has special centers in the spinal cord and brain, as well as a number of nerve nodes located outside the spinal cord and brain. This part of the nervous system is subdivided into:

Sympathetic (innervation of smooth muscles of blood vessels, internal organs, glands), the centers of which are located in the thoracolumbar spinal cord;

Parasympathetic (innervation of the pupil, salivary and lacrimal glands, respiratory organs, organs located in the pelvic cavity), the centers of which are located in the brain.

The activity of the sympathetic and parasympathetic nervous system is antagonistic in nature: the sympathetic nervous system acts stimulating, the parasympathetic - depressing. For example, the heart is innervated by the sympathetic and vagus nerves. The vagus nerve extending from the parasympathetic center slows down the heart rhythm, reduces the amount of contraction, lowers the excitability of the heart muscle and reduces the speed of the wave of irritation through the heart muscle. The sympathetic nerve acts in the opposite direction.

The central nervous system and cerebral cortex regulate all higher nervous activity through reflexes. There are genetically fixed reactions of the central nervous system to external and internal stimuli - food, sexual, defensive, indicative. These reactions are called innate, or unconditioned, reflexes. They are provided by the activity of the brain, the spinal cord stem, the autonomic nervous system.

Conditioned reflexes are acquired individual adaptive reactions of animals that arise on the basis of the formation of a temporary connection between a stimulus and an unconditioned reflex act. An example of such reflexes is the realization of natural needs in a certain place in the apartment. The center of the formation of this type of reflex is also the cerebral cortex.

The nervous system of cats allows you to instantly navigate in space and react with lightning speed. Animals have a large area of ​​connections between nerve cells in the brain. Scientists have calculated that one cell contains up to tens of thousands of synapses - connections with other cells. This allows the cat to have a good memory and associative perception.

Various excitations coming from the external environment and internal organs of the animal are perceived by the sense organs and then analyzed in the cerebral cortex.

Cat's senses or analyzers

The animal's body has five sense organs: visual, balance-auditory, olfactory, gustatory and tactile. Each of these bodies has departments:

Peripheral (perceiving) - receptor;

Medium (conductive) - conductor;

Analyzing (in the cerebral cortex) - the brain center.

The organ of vision, or visual analyzer

The organ of vision is represented by the eye, which contains the visual receptor, the conductor - the optic nerve, cerebral pathways to the subcortical and cortical cerebral centers, as well as auxiliary organs.

The eye consists of the eyeball, which is connected by the optic nerve to the brain, and auxiliary organs. The eyeball itself has a spherical shape and is located in the bony cavity - the orbit, or the orbit formed by the bones of the skull. The anterior pole is convex, and the posterior pole is somewhat flattened. The figure shows a horizontal section of a vertebrate eye.

The eyeball consists of several membranes (outer, middle and inner), refractive media, nerves and blood vessels.

The outer, or fibrous, membrane, in turn, is divided into the white, or sclera, and the cornea.

The tunica albuginea, or sclera, is a solid material that covers 4 /5 eyeball, with the exception of the anterior pole. It plays the role of a strong skeleton of the wall of the eye, the tendons of the eye muscles are attached to it.

The cornea is a transparent, dense and rather thick membrane. It contains many nerves, but does not have blood vessels, is involved in conducting light to the retina, and perceives pain and pressure. The junction of the cornea into the sclera is called the limbus (edge).

The middle, or choroid, consists of the iris, ciliary body and choroid.

The iris is the pigmented and anterior part of the middle membrane, in the central part of which there is an opening - the pupil. In cats, in daylight, it has an upright-oval or slit-like shape. Smooth muscle tissue forms two muscles in the iris - the sphincter (annular) and the pupil dilator (radial), with the help of which the pupil, expanding or narrowing, regulates the flow of light rays into the eyeball. If the cat's pupils are wide open and round in daylight, this indicates a high arousal of the animal, the effect of medication, or some kind of disease. The name of the iris comes from the Greek word "iris", that is, "carrier of color" due to certain pigments. The color of the cat's eyes, which varies from blue to golden, depends on the different intensity of the dye. In albinos - animals with a congenital lack of skin pigmentation - the eyes are usually red. This is due to the color of the blood in the vessels of the eye. A kitten's eye color can change with age.

The ciliary body is a thickened part of the middle shell, located in the form of a ring up to 10 mm wide along the periphery of the posterior surface of the iris between it and the choroid itself. Its main part is the ciliary muscle, to which the zinn (lens) ligament is attached, which supports the lens capsule, under the action of which the lens becomes more or less convex.

Own choroid - the posterior part of the middle membrane of the eyeball, located between the sclera and the retina, feeding the latter. It has a large number of blood vessels.

The inner shell, or retina, has a back and an anterior portion.

The posterior part, the visual, lines most of the wall of the eyeball, where light stimuli are perceived and converted into a nerve signal. The visual part consists of the nervous (internal, photosensitive, facing the vitreous) and pigment (external, adjacent to the choroid) layers. The nerve layer contains rods and cones - photoreceptor, primary sensory nerve cells, which carry out light and color perception, respectively. The ratio of rods to cones in a cat is approximately 25: 1 (in humans - 4: 1). When light enters them, a chemical reaction takes place. Rods and cones differ in their functions. Rods are receptors for twilight vision, providing black and white perception. Cones are daytime vision receptors that provide color vision. Rods are usually predominant in nocturnal organisms. Therefore, cats can see perfectly in the dark and can hunt at night.

The front part, blind, covers the ciliary body and iris from the inside and grows together with them. It consists of pigment cells devoid of a light-sensitive layer.

The place of transition of the retina to the optic nerve is called a blind spot. It has no light-sensitive cells. In the center of the retina there is a rounded yellow spot with a fossa in the center. It is an area of ​​good color perception.

Behind the retina there is a layer of special cells with crystals - a tapetum, or a mirror (literally translated from Latin means "luminous wallpaper"). This layer reflects unabsorbed light rays to the photoreceptors, which enhances twilight vision, and also causes the eyes to glow with reflected light. On a quiet, windless night, the glow of the cat's eyes is visible at a distance of up to 80 m. A ray of light falling on the cat's eye is reflected in a yellow-green color.

The cavity of the eyeball is filled with light-refracting media: the lens and the contents of the anterior, posterior and vitreous chambers of the eye.

The anterior chamber of the eye is the space between the cornea and the iris, the posterior chamber of the eye is the space between the iris and the lens. The chamber fluid nourishes the eye tissues, removes metabolic products, and conducts light rays from the cornea to the lens.

The lens is a dense transparent body in the form of a biconvex lens and located between the iris and the vitreous. This is the organ of accommodation. With age, the lens becomes less elastic. A feature of the structure of the lens of the cat's eye is the central fossa in the form of a disk.

The vitreous chamber is the space between the lens and the retina that is filled with the vitreous humor (a transparent, gelatinous mass, 98% water). Its functions are to maintain the shape and tone of the eyeball, conduct light and participate in intraocular metabolism.

The cat is a nocturnal predator, but these animals cannot see in absolute darkness.

The auxiliary organs of the eye are represented by the eyelids, lacrimal apparatus, eye muscles, orbit, periorbital and fascia.

The eyelid is a skin-mucous-muscular fold located in front of the eyeball and protects the eye from mechanical damage. The front part of the eyeball to the cornea and the inner surface of the eyelids are covered with a mucous membrane - the conjunctiva.

In a cat, the upper and lower eyelids close the eye, adhering tightly to its surface. Between them is the transverse gap of the eyelids. The upper eyelid is more developed and mobile. The upper eyelashes are more numerous. The eyelashes of the lower eyelid are not clearly expressed. In the inner corner of the eye is the third eyelid - the blinking membrane, which is a semilunar fold of the conjunctiva. This membrane can stretch over the entire cat's eye. The third eyelid removes dust particles from the surface of the visible cornea. The prolapse of the third eyelid is a sign that the animal is not healthy.

The lacrimal apparatus is the lacrimal glands, tubules, lacrimal sac and nasolacrimal duct. In the inner corner of the eye, the cat has a small thickening of the conjunctiva - a lacrimal tubercle with a lacrimal canal in the center, around which there is a small depression - a lacrimal lake. The excretory ducts of the lacrimal glands open in the conjunctiva of the eyelid. The lacrimal secretion consists mainly of water and contains the enzyme lysozyme, which has a bactericidal effect. When the eyelids move, the lacrimal fluid washes and cleans the conjunctiva, collecting in the lacrimal lake. Then the secret enters the lacrimal canals, which open in the inner corner of the eye. Through them, the tear enters the lacrimal sac, from which the nasolacrimal duct begins.

The location of the eyeball is called the orbit, and the place where the back of the eyeball, optic nerve, muscles, fascia, vessels and nerves are located is called periorbital. In total, there are 7 eye muscles located inside the periorbitis. They provide movement of the eyeball in different directions within the orbit.

The eyes of cats are relatively large compared to body size. They are slanted, almond-shaped and round. A cat's eyes are positioned so that both look in the same direction, and thus the field of view intersects in the center, such as in owls, which provides the cat with spatial (stereoscopic) vision. Visual acuity in cats is 6 times higher than in humans, so they are able to correctly assess the distance to the object of observation. Animals see objects that move better. Kittens are born blind and begin to see at 2 weeks of age.

A cat's eyes are designed like the diaphragm in a camera: its pupils let in just as much light as needed to “illuminate the frame” onto the retina, expanding to see more clearly in low light, and turning into narrow slits in bright sunlight. The pupils dilate when the cat is defending and constrict when she attacks.

Until about the middle of the XX century. cats were believed to be color-blind. It has now been proven that cats not only distinguish the slightest shades of gray (up to 26), but also recognize 6 colors. However, the perception of color, in comparison with a person, is weak, less contrasting and bright.

Equilibrium auditory organ, or statoacoustic analyzer

This analyzer consists of a receptor - the vestibular cochlear organ, pathways and brain centers. The vestibular cochlear organ, or ear, is a complex complex of structures that provides the perception of sound, vibration and gravitational signals. The receptors that perceive these signals are located in the membranous vestibule and the membranous cochlea, which gave rise to the name of the organ.

The equilibrium auditory organ consists of the outer, middle and inner ear. The outer ear is the sound-collecting part of the organ, consisting of the auricle, more than 20 muscles, and the external auditory canal. The auricle is a funnel-shaped skin fold covered with hair with a pointed or rounded end, small in size and very mobile. It is based on elastic cartilage. On the posterior edge of the shell, on its inner surface, there is a skin pocket.

The auricle muscles are well developed. They provide mobility of the auricle, turning it towards the sound source. The external auditory canal, which is a narrow tube, serves to conduct sound vibrations to the eardrum. Its base consists of elastic cartilage and a stone tube. The middle ear is a sound-conducting and sound-transforming organ of the vestibular cochlear organ, represented by the tympanic cavity with a chain of auditory ossicles in it. The tympanic cavity is located in the tympanic part of the petrosal bone. On the back wall of this cavity there are 2 openings, or windows: the window of the vestibule, closed by the stapes, and the window of the cochlea, closed by the inner membrane. On the front wall there is an opening leading into the auditory (Eustachian) tube, which opens into the pharynx. The eardrum is a weakly expandable membrane, about 0.1 mm thick, that separates the middle from the outer ear. The auditory ossicles of the middle ear are the malleus, incus, lenticular bone, and stapes. With the help of ligaments and joints, they are connected into a chain, which rests against the eardrum at one end and against the window of the vestibule with the other. Through this chain of the auditory ossicles, sound vibrations are transmitted from the eardrum to the inner ear fluid - perilymph.

The inner ear is a spiral-shaped section of the vestibular cochlear organ, in which the balance and hearing receptors are located. It consists of bony and membranous labyrinths. The bony labyrinth is a system of cavities in the petrous part of the temporal bone. In it, a vestibule, three semicircular canals and a cochlea are distinguished. The membranous labyrinth is a collection of interconnected small cavities, the walls of which are formed by connective tissue membranes, and the cavities themselves are filled with fluid - endolymph. It includes semicircular canals, oval and round sacs, and a membranous cochlea. From the side of the cavity, the membrane is covered with epithelium, which forms the receptor part of the auditory analyzer, which is called the spiral (Corti) organ. It consists of auditory (hair) and supporting (supporting) cells. Nervous excitement arising in the auditory cells is conducted to the cortical centers of the auditory analyzer. Waves of a certain length excite auditory receptors, in which the physical energy of sound vibrations is converted into nerve impulses. Receptor cells form the auditory nerve (the number of nerve endings in the auditory nerves is 52 thousand, while in humans there are about 31 thousand in one auditory nerve).

In the oval small and round sacs there are statoliths, which, together with the neuroepithelium of the equilibrium scallops (they are located on the inner surface of the membranous ampullae formed at the border of the semicircular canal with the oval sac) and sensitive or equilibrium spots or macules (located on the walls) make up the vestibular apparatus, which perceives movement of the head and changes in its position associated with a sense of balance. The receptors of the small oval sac are excited when the vertical position of the head changes, and the large round one - when the horizontal position changes. The movement of the cat in space causes the fluid to overflow in the tubules. The movement signal is sent to the brain. Thanks to the organ of balance, the cat perfectly orientates itself in space and maintains balance when moving at high altitudes (along roof parapets, along fences, tree branches, along narrow cornices outside the window). A well-developed vestibular apparatus allows the cat, when falling in flight, to change its body position and land on its paws.

Due to the peculiarities of the structure of the ear, namely the organ of hearing, cats hear perfectly. The range of perception of sound waves in cats is very wide (significantly exceeds the human one - up to 20 kHz and canine - up to 40 kHz) - from 10 to 65,000 vibrations, and according to some sources - even up to 80,000 vibrations per second, that is, 80 kHz. Cats can hear sounds in a range of up to 10 octaves with a difference of only 1 /10 tone. Cats are able to pick up ultrasound and high frequency sounds (such as squeaking mice). They can also accurately distinguish between two adjacent sound sources. This, most likely, explains the “supernatural” feeling that allows the cat to know that someone is approaching the front door even before the door knocks or bells are heard - this animal senses even faint sound vibrations. Such hearing helps to hunt mice and small insects, communicate with kittens and learn about the arrival of the owner from afar by the sound of his steps. Cats may be picking up sound vibrations as they pass through solid objects.

It has been noticed that cats only hear what they want to hear. A loud familiar sound, which is not interesting to the cat, can leave her indifferent, she will sleep without reacting to it. But if an unfamiliar quiet sound is heard nearby, she will be on the alert.

However, not all cats hear so well. So, white cats with blue eyes often suffer from congenital deafness, but even they have the ability to sense sound in other parts of the body (in cats, like in some other mammals, the so-called bone transmission of sound is well developed).

The olfactory organ, or olfactory analyzer

Smell is the ability of animals to perceive a certain property (smell) of chemical compounds in the environment. The molecules of odorous substances, which are signals of certain objects or events in the external environment, together with the air reach the olfactory cells when they are inhaled through the nose or through the mouth (while eating, through the choanas).

The sense of smell in cats is weaker than in dogs, but stronger than the sense of smell in humans. The olfactory organ is located deep in the nasal cavity, namely in the common nasal passage, in its upper part, a small area covered with the olfactory epithelium, where the receptor cells are located. The cells of the olfactory epithelium are the beginning of the olfactory nerves, through which excitation is transmitted to the brain. Between them are the supporting cells that produce mucus. There are 10-12 hairs on the surface of the receptor cells, which react to aromatic molecules. In addition to these receptors, the cat has an additional organ of smell - the Jacobson organ, which also serves as an organ of taste. It consists of 2 thin tubules no more than 1 cm long. They originate in the oral cavity and pass along the palate. Its opening is in the palate behind the incisors. The cat opens its mouth and draws in air to use this organ, "drinks the smell". This lifts the upper lip and nose slightly. It seems that the animal is dissatisfied with something. In fact, the cat at this moment is completely focused on some kind of smell.

Cats sense smells 14 times stronger than humans, since they have 60–80 million olfactory receptors (in humans, 5–20 million). Each contact with another living creature presupposes a preliminary sniffing, and all odorous marks and traces on the site are carefully rechecked daily. When a cat rubs against an object, it leaves its own scent on it. Cats can also leave their scent on their relatives. The next time they meet, they will definitely recognize him.

The smell that a cat exudes can provide information to its relatives about the sex, age and health of the animal. A cat that should be in heat in 1–2 days exudes a certain odor that attracts the cat to her. However, the human sense of smell cannot sense it.

Cats live in a world of odors inaccessible to humans. The smell of some plants - valerian, thyme, catnip or catnip - makes cats lose their heads. So, for example, the smell of valerian (valerian officinalis, or valerian pharmacy, or cat herb, or cat root) has a calming effect on cats. Possessing a strong and peculiar smell, spicy and sweetish taste, it acts on them magically. It has been established that preparations based on valerian have a calming effect on the nervous system, and it is the rhizomes collected in the autumn in the fruiting phase that attract cats. After sniffing and licking the preparations from this plant, cats become calmer, slightly drowsy, affectionate. This can be used in training.

Cats love the smell of catnip, and the addiction to this plant increases markedly with age. On close contact with catnip, they feel drunk.

For the most part, cats do not tolerate pungent odors (lemon and orange peel and garden rue), which is used, for example, to wean them from tearing their claws in the wrong place.

The organ of taste, or taste analyzer

Taste is an analysis of the quality of various substances entering the oral cavity. The gustatory sensation arises as a result of the action of chemical solutions on the chemoreceptors of the taste papillae of the tongue and the mucous membrane of the oral cavity. This produces a sensation of bitter, sour, salty, sweet or mixed taste. It has been noticed that cats are less sensitive to sweet taste. The sense of taste in newborns appears earlier than other sensations.

Taste buds contain taste buds with neuronal epithelial cells. They are located on the surface of the tongue and on the oral mucosa. There are 3 types of papillae - mushroom, roller-shaped and leaf-shaped. On the outside, the taste bud is in contact with food substances, on the inside, it is connected with nerve fibers located on the tongue. Taste bulbs are distributed over the surface of the tongue in certain groups, forming taste zones that are mainly sensitive to certain substances. Dry food cannot affect the neuro-epithelial cells of the taste buds immersed in the mucous membrane. The food is moistened by grinding with plant moisture, as well as the secretion of the salivary glands, including the secretion secreted by the glands in the walls of the taste buds. Information about dissolved chemicals irritates the gustatory nerve endings. The resulting nervous excitement along the gustatory nerve is transmitted to the cerebral cortex, where a sensation of the main taste is created.

It should be noted that the sharpness of the cat's taste depends on the Jacobson's tubule, which is also an organ of smell, which allows the animal to avoid accidental poisoning. That is why cats are called gourmets and meticulous tasters of the food offered to them.

The organ of touch, or skin analyzer

Touch is the ability of animals to perceive various external influences (touch, pressure, stretching, cold, heat). It is carried out by receptors of the skin, musculoskeletal system (muscles, tendons and joints), mucous membranes (lips, tongue and other organs). The tactile sensation can be diverse, as it arises as a result of the complex perception of various properties of the stimulus acting on the skin and subcutaneous tissues. Through touch, the shape, size, temperature and consistency of the stimulus, position and movement of the body in space are determined. It is based on irritation of special structures - mechanoreceptors, thermoreceptors, pain receptors - and the transformation of incoming signals in the central nervous system into the appropriate type of sensitivity (tactile, temperature, pain or nociceptive).

In cats, the sense of touch is very well developed. A cat's temperature sensitivity is different from human perception. A person is not able to contact with hot objects for a long time. The cat, on the other hand, can walk on a hot roof or lie on a hot stove, outwardly remaining completely calm. This is due to the fact that most of the cat's skin surface is generally not sensitive to contact with hot surfaces, but the upper lip and nose are very sensitive. Like other mammals, a cat determines the temperature of objects it touches, primarily with the help of heat and cold receptors - tiny sensory organs located in the skin. Although the former are mainly responsible for the perception of heat, and the latter for the perception of cold, their specialization is still not absolute. Thus, some cold receptors can also be excited when exposed to a hot surface, at least in a limited temperature range; there are more cold receptors and they are located closer to the surface of the body than heat receptors.

Each receptor is constantly active, and nerve impulses of a more or less stable frequency can be registered on its fibers. Cooling or heating of the skin causes a change in frequency, accompanied by new discharges of impulses. In this case, the effect of summation is observed, when the thresholds of perception during irritation of large areas of the skin are reduced compared to the thresholds of single nerve endings.

However, in cats, thermoreceptors are located not only on the surface of the body in the skin, but also in the subcutaneous vessels, in the upper respiratory tract and digestive tract, even in various parts of the brain and spinal cord. Due to this, the sensation of warmth or coldness arises as a result of the integration in the central nervous system of impulses coming from thermoreceptors located in different parts of the body. Some thermoreceptors are covered with special capsules, while others are bare nerve endings.

The abundance of temperature receptors, scattered almost throughout the body, allows the cat to maintain a certain thermal balance by comparing its internal temperature with the temperature of the environment. Receiving information about the internal and external temperatures, the cat tries in every possible way to reduce the ratio between them to the level that is optimal for itself. True, she has limited opportunities for this. There are clearly not enough sweat and sebaceous glands on the cat's body, through which it could get rid of excess heat. Sweat glands are located between the pads of the paws, around the nipples, on the cheeks and lips, and around the anal glands. Sweating chills the cat. If this cooling is not enough and the cat feels temperature discomfort, it looks for a place where overheating is excluded, which reduces the metabolic rate in the body. If any circumstances force her to be in an unfavorable place, she overheats. This can be determined by the short and fast breathing, wide open eyes of the animal. On a hot day, a cat constantly changes its location, moving from one place to another. For the same purpose, the cat adopts various postures that allow it to increase the cooling of the body surface. On a hot day, we often see cats lying in the sun, stretching out and showing their belly. They behave in the same way near a warm radiator or fireplace in winter. But as soon as the temperature drops, the cat immediately curls up into a ball. The normal average body temperature of a cat is 38.2 ° C (except for hairless cat breeds, in which the temperature is 2-3 ° higher). Temperatures below 18 and above 43 ° C are considered deadly for a cat.

Pain signals the animal about the emerging danger and evokes defensive responses aimed at eliminating harsh stimuli. An example of the manifestation of pain sensitivity in cats is stroking against the fur, which is expressed by a defensive reaction on the part of the cat, which uses claws and teeth. Painful sensations when stroking in most cases appear from electric discharges arising from friction.

Tactile sensitivity is provided by special, touch-sensitive hairs - vibrissae. Vibrissae are long and in places very hard hairs growing on the upper and lower lip (up to 30 hairs), around the eyes (up to 12), on the cheekbones (2 each) and the outer side of the forelegs (up to 6). Their roots are deep in the skin, in areas rich in nerve endings. They protrude into a sac filled with blood - the sinus. On the wall of the sinus are tactile bodies, which are excited by the movement of sensitive hairs. Due to the uniform propagation of the compression wave in the blood sac (hydraulic principle), with one movement of the vibrissa, nerve cells are excited, therefore, even a light touch is enough for a reaction to occur. The most noticeable vibrissae on the cheekbones are whiskers, which also work as mechanoreceptors. They help the cat determine if it will fit through the hole. In total, the cat has 24 main whiskers, located in four rows on each side. The cat can control the two upper rows independently of the lower ones.

Cats receive signals and information even with the smallest fluctuations in the air. The animal moves its whiskers due to the presence of short small muscles located at the very roots. By the position of the whiskers, you can also find out about the mood of the cat. For example, when she is afraid or defensive, her mustache is pulled back and pressed against her head. Do not under any circumstances cut the whiskers of your cats and try not to let the animal burn them too much.

Cats are not helpless in complete darkness and can move around without touching anything. Air waves generated during the movement of the cat are reflected from nearby objects, which are perceived by vibrissae. There are sensitive hairs on the forelimbs, with which the animal senses barely noticeable vibrations of the floor, soil, and also receives information about obstacles. The hairs around the eyes are mainly protective. As soon as they touch something, the animal immediately closes its eyes.

The sense of touch develops in the kitten through early contact with the mother. The cat washes the baby with its tongue and paws it moves it closer to itself. This is how the kitten learns to associate the mother's tongue with gentle caring. Later, maternal care will be replaced by stroking with a human hand. Sometimes cats get bored with the vibrissae of their babies and they simply gnaw them off. Perhaps, cats in this way strive so that some overly independent kitten does not come out of the nest ahead of time. It takes almost six months before the babies grow mustache again.

Petting and grooming has been found to reduce stress by slowing down the heart rate. This is one of the reasons that the cat starts to wash. Cats seem to be able to sense tissue structure with their paws. They like the warm, soft fabric on which they prefer to sleep. Furry pets refuse to sit in the lap of someone wearing a cold, slippery dress or a coarse-woven suit.

Numerous stories (some of them are quite reliable) tell of how cats traveled hundreds of kilometers, separating their new home from the place where they lived before. Like carrier pigeons, cats have the ability to determine the right direction. The cat's eye is able to perceive not only optical stimuli in a wide range, but also acoustic signals. Cats perceive an accurate sound picture of their environment, registering in their memory various characteristic noises (the sound of a bell, the noise of a plant, etc.), determine their distance, strength and angle of incidence of sound. Usually, a cat does not move further from its home for more than 600–800 m. If it does not have a stable attachment to a person, it becomes very much accustomed to its home and hunting area. If you move a cat to an unfamiliar place, it can, albeit adventurously, overcome a path longer than 100 km and return back.

Cat digestive system

The digestive system carries out the exchange of substances between the body and the environment. Through the digestive organs, all the substances it needs - proteins, fats, carbohydrates, mineral salts, vitamins - enter the body, and part of the metabolic products and indigestible food residues are thrown into the external environment.

An equally important function of the digestive system is the barrier function, i.e. preventing harmful bacteria and viruses from entering the cat's body. The complete cycle of digestion - digestion, absorption of nutrients and elimination of undigested food debris - occurs within 24 hours.

The digestive organs include the oral cavity, pharynx, esophagus, small and large intestines.

An important role in digestion is played by the endocrine glands: liver, pancreas and gallbladder.

Being a predator by nature, the cat gnaws, tears and cuts meat food with its teeth, after which it swallows it, practically without chewing. The salivary glands in the cat's mouth moisten the food to help it pass through the esophagus and into the stomach. Food already in the oral cavity begins to break down under the influence of saliva. This process is called mechanical digestion.

The organs of the urinary system are responsible for the removal of excess fluid from the body: the bladder, kidneys and ureters. In them, the formation, accumulation and excretion of urine with the products of digestion and metabolism dissolved in it takes place, they also regulate the salt and water balance in the cat's body.

Urine production takes place in the kidneys, where the nephrons filter waste substances brought in from the liver. An Abyssinian cat produces up to 100 ml of urine every day. In addition, the kidneys regulate blood pressure, maintain the chemical balance of the blood, activate vitamin D and release the hormone erythropoietin, which stimulates the formation of red blood cells.

From the kidneys, urine enters the bladder through the ureters, where it accumulates until the next urination. Control of urination is carried out with the help of the guard muscle located in the bladder, which does not allow urine to be excreted spontaneously.

The urethra, through which the fluid accumulated in the bladder is removed to the outside, is short in cats and ends in the vagina, and in cats it is long, curved and ends at the head of the penis. A distinctive physiological feature of the urethra of cats is stenoses - special narrowings that serve for the rapid passage of urine containing sediment.

Reproductive organs of cats

The reproductive system of the cat consists of testes, seminal ducts, urogenital canal, accessory gonads and penis.

Testes(or testicles) - the main pair of male sex glands in cats, in which, after reaching puberty, the formation of sperm and the male sex hormone - testosterone occurs. Sperm production continues throughout the entire reproductive period (all life or until the moment of castration). As a result of exposure to testosterone, the appearance of the cat changes: in comparison with the body, the head slightly increases, the cheekbones become "heavy", and the body becomes lean and athletic.

Since spermatozoa are best formed at a temperature slightly lower than body temperature, the testes of the cat are lowered into the scrotum - a two-chambered musculocutaneous formation located below the anus.

Until the moment of ejaculation, sperm accumulate in the epididymis. At the end of mating, they are directed along two seminal ducts to the prostate, where the ducts join and form an ejaculatory canal that flows into the urethra and ends at the head of the penis.

The penis is used to inject semen into the cat's genitals and to drain urine from the bladder, and consists of the head, body, and root. The basis of the body of the penis is the two arterial corpus cavernosum and the cavernous (porous) body of the urethra. The root anchors the penis to the edge of the ischium. By six months, under the influence of testosterone, the cat's penis becomes covered with keratinized spines, which, when mated, irritate the cat's vagina and stimulate the release of eggs.

The cat's urine contains ferromones, with the help of which he tries to attract a cat that is in the period of sexual heat.

The reproductive system of the cat consists of the ovaries, uterus, and external genitalia. Also, the mammary glands are referred to the reproductive system of the cat.

Ovaries Cats, which produce eggs and the female sex hormones estrogen and progesterone, are located near the kidneys in the abdomen. Unlike the reproductive system of dogs and most other mammals, a cat's ovaries do not release eggs until they mate. Ovulation in cats occurs only after mating, which stimulates the release of eggs, this phenomenon is called non-spontaneous ovulation.

The eggs released as a result of mating are captured by the ovarian fringe and descend into the oviducts, where they are fertilized by sperm.

From the oviducts, fertilized eggs are sent to the uterus. The uterus of a cat has two long elastic horns in which fetuses develop. The diameter of empty uterine horns is only a few millimeters, while during pregnancy, their diameter can reach 4-5 cm.

The cat's uterus connects to the vagina through the cervix, which is normally closed. The exceptions are periods of estrus and childbirth. The external genitalia of the cat are presented in the form of the vulva (labia). On the border between the vagina and the vulva there is an outlet of the urethra, through which the hormone estrogen is released during estrus along with urine.

Thus, the cat informs the cat about its readiness for mating.

The hormones produced by the cat's ovaries stimulate the development of the mammary glands. A cat normally has 4 pairs of nipples, but extra nipples are not uncommon (usually solitary and rudimentary). During lactation, milk is distributed unevenly in them: the pair of nipples closest to the breast produces little milk, and as the distance from the breast area increases, milk becomes more - the most productive nipples are located near the groin area.

Surely every owner of a mustachioed four-legged pet will be interested and useful to find out “what makes up” his miracle and how much the anatomy of a cat differs from that of a human. Cats, as you know, belong to the class of mammals, like us, and therefore we must have a lot in common. But to find out in more detail what a cat's skeleton is and due to which all vital processes in the body of our beloved purrs are carried out, our informative article will help you!

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Cat skeleton

Since ancient times, the cat has been considered the standard of grace and grace. Hardly anyone can compare with her in the ability to climb trees, in agility and the ability to land on her soft cat paws. Nature created our beloved purrs as ideal agile predators, but we turned them into pampered pets. However, in necessary situations the cat quickly "remembers" its purpose, and the cat's skeleton and muscles help her in this.

Skull

The cat's skull has almost equal facial and cerebral regions. This tells us that the intelligence of domestic predators is very well developed. The bite of the purr is straight and tick-shaped, and the size of the jaw is impressive compared to the small size of the animal, which makes the predator dangerous and unpredictable. The teeth of cats tend to change, but by seven months the animal should acquire permanent teeth in the amount of 30 pieces.

The main role is played by the canines, which are quite long and sharp, and the incisors are auxiliary. The cat's skull has very large eye sockets, because the cat's keen eyes are impressive in size.

Torso bones

Cats have an unusually flexible spine. This flexibility is created due to the fact that it consists of small movable bones, while having a high density. Larger bones make up the cervical region, there are 7 vertebrae in it, two of which have poetic names - atlas and epistrophy. These vertebrae tend to rotate 180 degrees.

The thoracic region includes 13 vertebrae, to which 12 pairs of ribs are attached on both sides. 8 pairs of them are eventually attached to the sternum, and 5 pairs are not attached to anything. This ensures the flexibility of the cat's body and its ability to turn around even in a very confined space.

This is followed by the lumbar region, which includes 7 vertebrae, enlarging as it approaches the tail. The lumbar vertebrae have many strong protrusions, because muscles and tendons are attached to them that hold all the organs of the abdominal cavity. In the sacral region, there are 3 powerful fused vertebrae. And the longest is the caudal section, 21-23 decreasing towards the end of the vertebra; some breeds, which are characterized by a shortened tail, have fewer caudal vertebrae.

One of the leading features of the cat's skeleton is the structure of its collarbones. The fact is that they are in a rudimentary state and do not restrict the movement of the animal, as, for example, occurs in dogs. Thanks to the "underdeveloped" collarbones, the cat can crawl into any gap, as long as its head passes.

Limb bones

Our companion cats walk on toes, and the back of the paw was once a foot. The front paws of the cat have 5 fingers, the extreme phalanx of which is the basis for the claw. The first finger is a rudiment and the claw is not removed from it.

The hind legs of the cats are longer and the joints are stronger there, this allows the cat to withstand sudden heavy loads. In addition, this structure of the limbs allows the cat to develop tremendous speed both horizontally and vertically. This is why cats are such a good dart frog.

The cat's hind legs have fewer toes - 4, and the fifth is also a rudiment. Based on how many fingers a cat has, it may have polydactyly (more fingers than it should) or oligodactyly (missing fingers).

Internal organs

The internal structure of a cat is a set of all the same systems of life that are inherent in other mammals. Let's consider them in order.

Circulatory and respiratory systems

The circulatory system in a cat does not have any special differences, the pulse of the animal in a calm state is from 100 to 150 beats per minute and can be measured by pressing the femoral artery. Normally, the blood in the animal's body should be about 7% of its mass, cat's blood is specific and clotted faster than human blood.

With each beat, the cat's heart passes approximately 3 ml of blood. The blood circulation of a cat is similar to that in humans: in the lungs, the blood is saturated with oxygen, and in the digestive organs with useful substances. After that, the heart carries fresh blood through the arteries to all organs. And through the veins, blood flows back to the heart, so that it again sends it to the lungs for enrichment with the necessary oxygen.

The respiratory system, in addition to the function of supplying blood with oxygen, is also involved in thermoregulation. The respiratory rate in cats is 20-30 breaths per minute, in kittens about 40 breaths, and inhalation is through the nose. The air inhaled by the cat through the nose is first warmed and filtered, then enters the larynx, trachea and lungs of the animal through the pharynx. There is an assumption that the cat makes purring sounds with the help of pocket folds, which are located in the larynx.

Excretory and digestive systems

The cat's digestive system also has a lot in common with the human. It begins with the mouth and ends with the rectum and sphincter. Between them are the pharynx, esophagus, stomach, small and large intestines. The pancreas and liver are also considered to be part of the digestive system.

It is noteworthy that the cat's stomach can digest rather large pieces of food, which the cat bites off thanks to the strong and sharp incisors and canines. The intestine of the cat is about 3 times longer than the body of the animal and is 1-1.8 m. The cat also has a cecum, but the appendix is ​​not present in the murk.

The removal of fluid from the cat's body occurs through the urinary system - the kidneys, bladder and ureters. The formation of urine begins in the kidneys, which also regulates the chemistry of the blood. Further, urine moves into the bladder through the ureters, from where it is removed from the body. The process of urination is controlled by the trailing muscle, which prevents spontaneous urination. The following video will help you understand the structure of a cat by literally looking inside the cat's body!

Reproductive system

The purpose of the reproductive system is obvious - it is the continuation of the feline genus. In a cat, the genitals are the gonads, testes, vas deferens, and the penis. In a cat, these are the ovaries, uterus, oviducts and external genital organs. The time for puberty for cats is 6-8 months, however, a safe age for mating, when full-fledged offspring can be expected, is at least 10 months. During puberty, the behavior of cats changes greatly and they show their willingness to reproduce in every possible way.

Sense organs

Nature has endowed our smaller brothers with unusually developed sense organs. Our pets see, hear and smell much sharper than us.

Eye

A cat's eyes are significantly larger in relation to the size of its body than a person's. The cornea of ​​the purr's eye is more convex, which means that the quality of the image perceived by the cat's eye is higher. Cats can distinguish colors, it is believed that at least 3 colors they see are red, green and blue. The pupil of the cat's eye, like that of the human, is able to expand and contract thanks to a special contraction muscle. Our mustachioed friends have unusually keen eyesight, but they cannot see what is happening under their noses, the optimal distance for the perception of information by the cat's eye is 2-6 m.

The structure of a cat's eye is distinguished by the presence in it of a special vascular layer called the tapetum, thanks to which the cat's eyes can see in the dark and glow mystically at the same time. In addition, our pets may have differently pigmented iris, which is why they are so "odd-eyed".

Ear

The structure of a cat's ear gives it the ability to perceive sounds in the range from 30 hertz to 45 kilohertz, and purrs can also pick up ultrasound. Almost all cats have erect ears, with the exception of some breeds. Cats, unlike humans, can actively wiggle their ears, 27 muscles help them in this. All purrs have a fold of skin in the inner part of the auricle, which some call the "third ear". It is noteworthy that sometimes completely white cats are born deaf due to gene mutations.

Nose

The cat's nose is considered one of the most vulnerable organs of the purr's body, especially its tip. By the way, the tip of the nose is completely devoid of vegetation and can be of different colors depending on the breed of the cat. The sense of smell in cats is quite well developed, since they have a greater number of olfactory receptors compared to us.

According to their ability to recognize smells, cats belong to macro-somatic animals, while humans are micro-somatic creatures and the number of smells they perceive is very limited. However, compared to dogs, cats still have a weaker sense of smell.

Photo gallery

Video "Cats from a Scientific Point of View"

A very interesting and informative video with a selection of little-known facts about our furry pets at the end of our tour of feline anatomy!

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