Heart fabric. Cardiac muscular fabric: development source, structural and functional characteristics of the fabric, features innervation and contractile activity, types of cardiomyocytes, regeneration

Date: 04.03.2020

Muscular fabrics.

Muscular fabrics - These are a different fabric by origin and structure, but similar to ability to reduce.

Morphofunctional characteristic of muscular fabric:

1. Ability to reduce.

2. Muscle has a reduction in the expense of special organelle - miofibrilliFormed by the threads of a contractile protein, actin and myosein.

3. The sarcoplasm contains the inclusion of glycogen, lipids and mioglobinwhich binds oxygen on himself. General purpose organides are poorly developed, only EPS and mitochondria are well developed, which is located in the chain between myofibrils.

Functions:

1. Movement of the body and its parts in space;

2. Muscles give the shape of the body;

Classification

1. Morphofunctional:

A) smooth,

B) transverse (skeletal, cardiac).

2. Genetic (chlopin)

Smooth muscular fabric Develops from 3 sources:

BUT) from Mezenhima - Muscular tissue, forming the shell of internal organs and walls of vessels.

B) from Etoderma - Myepithelocytes - cells with ability to reduce, have a star form, in the form of baskets cover end departments and small output ducts of ectodermal glands. With its reduction, contribute to the allocation of the secret.

IN) neural origin - These are muscles of narrowing and expanding pupil (believe that they are developing from neuroglia).

Cross-resistant muscular fabric Develops from 2 sources:

BUT) from Miotomskeletal fabrics are laid.

B) from myoepicardial plates visceral leaf of splashnotoma In the cervical embryo, heart muscular fabric is laid.

Smooth muscular fabric

Histogenesis. Mesenchym cells are differentiated into the myocytes of which are formed.

Structural unit smooth muscle tissue is myocyt, and the structural and functional unit - floxt of smooth muscle cells.

Myocyt - Verena-shaped cell. The size of 2x8 microns during pregnancy increases to 500 microns and acquires a star form. The kernel shameful when the cage is reduced, the kernel bends or spirally twisted. Organelles of the total meaning are poorly developed (with the exception of mitochondria) and are located about the core poles. In cytoplasm - special organelles - miofibrils (represented by thefts of actin and myozin). Night actin form a three-dimensional network that is attached to the plasmolem of myocytes with special crosslinking proteins (Vinculin et al.), which are visible on micrographs as dense Tales (consist of alpha - actinine). Thread Mozin In a relaxed state of depolymerized, and when reduced, polymerization occurs, while they with actin threads forms an actinomyosine complex. Actin's plasmolem associated with its reducing threads, as a result of this, the cell is shortened and thickened. In addition to the reduction, calcium ions are in kaveylah formed by prying the cytlemma. Myocyte over plasmolemma is covered with a basal membrane, into which fibers of loose connective tissue with vessels and nerves forming endomisia. Here are the terminals of nerve fibers, ending not directly on myocytes, but between them. The mediator distinguished from them through the nexus (between cells) is transmitted immediately into several cells, which leads to a reduction in their entire formation.

Regeneration of Smooth Muscular Fabricmay go 3 ways:

1.compensator hypertrophy (increase the size of the cell),

2. Mitotic division of myocytes,

3. Increase in the number of myofibroblasts.

Transversely striped muscular fabric

Skeletal.

Histogenesis. Develops from Mesoderm Miotomes. In the development of the skeletal muscular stage, the following stages are distinguished:

1. myoblastic Stage - Cells of miotomes are loosened, with one part of the cells remain in place and participates in the formation of autochon muscle tissue, and the other part of the cells migrates into the places of future muscle bookmarks. In this case, the cells are differentiated in 2 directions: 1) myoblasts who are mothotically divided and 2) miosatellite.

2. formation of muscular tubes (miotub) - myoblasts merge among themselves and form symplast. Then, the symplast is formed by myofibrils located along the periphery, and the kernels in the center, resulting in mitubs or muscle tubes.

3. the formation of myosimplast - As a result of the far differentiation of the Mitubs turn into miosimplastAt the same time, the kernels are shifted to the perfigine, and the myofibrils are in the center and take an ordered location, which corresponds to the formation of muscle fiber. Miosatellite They are located on the surface of myosimplests and remain unoccupied. Correct kabij skeletal muscle tissue. Due to them, there is a regeneration of muscle fiber.

The structural unit of skeletal muscle tissue is muscular fiber, and structural and functional - mion. Muscular fiber - This is a myiosimplastic size reaching up to several cm and containing up to several tens of thousands of nuclei located along the periphery. In the center of the muscular fiber is up to two thousand bundles of myofibrils. Mion - It is muscle fiber, surrounded by a connective tissue with vessels and nerves.

Five devices distinguish fibers:

1. Trophic apparatus;

2. Contractor;

3. Specific membrane apparatus;

4. Support device;

5. Nervous apparatus.

1. TrophicAption represented by nuclei and organelles of the general meaning. The cores are located along the periphery of the fiber and have an extended shape, the borders of the muscle fiber are not expressed. There is a common organoid organoids (agranular EPS, Sarkosoma (Mitochondria), granular EPS is developed worse, poorly developed lysosomes, usually, they are located in the core poles) and special meaning (myofibrils).

2. Cutting machine – miofibrils (from 200 to 2500). They go parallel to each other longitudinally, optically inhomogeneous. Each myofibrill has dark and bright areas (discs). Dark discs are located opposite the dark, and bright opposite the light disks, therefore the pattern of transverse allocated fibers is created.

Threads of the contracting protein - mozin Thick and place one under the other, forming a disk A (anisotropic), which will flash M-line (mesophragm) consisting of a protein of a miomizin. Thin Nights aktin Also located one under the other, forming a light disk I (isotropic). It does not have a double bempraine, unlike the disk A. Nightin Aktin at some distance among the threads of myosin. The area of \u200b\u200bthe disk A, formed only by the threads of myozin is called H - strip, and a plot containing the filament of actin and myosin - and the strip. Disk I flashes zin. Z - Line (BELFRAGMA) is formed by an alpha-agctin protein having a media location. Proteins, nebulin and Totin contribute to the location of the acts of actin and myosin and their fixation in the Z-strip. The bodyfragm of adjacent beams is fixed with each other, as well as with the cortical layer of sarcoplasm with intermediate filaments. This contributes to the solid fixation of the discs and does not allow them to shift relative to each other.

Structural functional unit Miofibrill is sarcomer , within its limits there is a reduction in muscle fiber. It is represented by ½ I-disk + A-drive + ½ I-disk. When reducing the filament of actin, there are between the threads of myosin, inside the strips and disk i as such disappears.

Between beams, myofibrils is a chain of sarcos, as well as the tanks of the sarcoplasmic network at the level of the T-tube forming transversely located tanks (L-systems).

3. Specific membrane apparatus - It is formed by the T-tube (this is invagination of the cytlemma), which in mammals is at the level between dark and bright disks. Next to the T-tube there are terminal tanks of the sarcoplasmic network - agranular EPS, in which calcium ions accumulate. T-tube and two L-tanks form in aggregate triad . Triads play an important role in the initiation of muscle contraction.

4. Support - Educated meso - I. bulfragmami performing a reference function for a beam of myofibrils, as well as sarchatima . Sarchatimma (Muscular Fiber Sheath) is represented by two sheets: internal plasmolm, outdoor - basal membrane. Collagen and reticular fibers, forming the interlayer of connective tissue with vessels and nerves - in sarclatma endomisiasurrounding every fiber. Cells are located miosatellite Or myosatellitocytes - this type of cells is also formed from the Miotomes, giving two populations (myoblasts and myosatelistic). These are oval cells that have an oval kernel and all organelles and even a cell center. They are unlikely and participate in muscle fiber regeneration.

5. Nervous apparatus (See Nervous System - Motor Plaside).

Regeneration of skeletal cross-striped muscular fabric can go through:

1. compensatory hypertrophy,

2. Either the following way: when cutting muscle fiber, it is degenerating next to the cut and absorbed by macrophages. Then, in differentiated tanks, the EPS and the Golgi complex begin to form elements of sarcoplasm, and thickening is formed at the damaged ends - muscle kidneys growing towards each other. The myostels released during damage to the fiber are divided, merge among themselves and contribute to regeneration by completing in muscle fiber.

Histoophysiology of muscle contraction.

Molecule aktin It has a globular shape and consists of two chains globule, which spirally twist relative to each other, while the grooves are formed between these threads, which contains tropomyosine protein. The troponin protein molecules are located between the tropomosin at a certain distance. In calm state, these proteins cover the active centers of the actin protein. As a reduction, an excitation wave arises, which from the sarchatomma is transmitted by the T-tubes in the museum of muscle fiber and the sarcoplasmic network L-tank, calcium ions are ejected, which change the troponin configuration. Following this, Troponin shifts tropomyosine, resulting in active actorn protein centers. Belka molecules mozin Have a kind of golf stick. It distinguishes two heads and handle, while the heads and part of the handle are movable. During the reduction of myozin's head, moving along the active centers of the actin protein, tighten the actin molecules inside the drive of the disk A and the disk i almost disappears.

Muscle as an organ.

Muscular fiber is surrounded by a thin layer of loose fibrous connective tissue, this layer is called endomisia There are vessels and nerves in it. A bundle of muscle fibers is surrounded by a wider layer of connective tissue - visitia , and the whole muscle is covered with a dense fibrous connective tissue - epimise .

Distinguish three types of muscle fibers :

2. Red,

3. Intermediate.

White - (skeletal muscles), this is a volitional, fast-cutting muscles, which, with a reduction, is quickly tired, is characterized by the presence of ATP - the phase of the rapid type, and the low activity of succinate dehydrogenase, high-phosphorylase. The kernels are located along the periphery, and the myofibrils in the center, Belfragma at the level of a dark and light disk. White muscle fibers contain more myofibrils, but less than myoglobin, large glycogen stock.

Red - (Heart, Language) is an unallic muscles, the reduction of these fibers is a protracted tonic, without fatigue. Slow-type ATP phase, high activity of succinate dehydrogenase, low-phosphorylase, kernels are located in the center, myofibrils along the periphery, Belfragma at the T-tube level, contains more Mioglobin, providing red color of fibers than myofibrils.

Intermediate (Part of skeletal muscles) - occupy an intermediate position between the red and white type of muscle fibers.

Heart muscular fabric.

Educated 5 types of cells:

1. typical (contractile) musculature,

2. atypical - comprises R-cells (Paismaker cells) in the cytoplasm of which a lot of free calcium. It has the ability to excite both the impulse generation, are part of the rhythm driver, providing heart automatism. The pulse with the R-cell is transmitted to

3. transitional cells and then on

4. conductive Cells, with typical myocardium.

5. secretoryWe produce a sodium system, while they control the urinations.

Cardiac muscular fabric Refers to transverse and has a similar structure, as well as skeletal (i.e., there are the same devices), but differs from skeletal as follows:

1. If the skeletal muscle tissue is a symplast, then the hearter - has a cellular structure (cardiomyocytes).

2. Cardiomyocytes are connected with each other and form functional fibers.

3. Insert plates are the boundaries between the cells having a complex structure and containing interdigate, nexus and desmosomoms where the actin threads are woven.

4. Cells have one, two cores located in the center. And the bunches of the Miofibrill lie along the periphery.

5. Cardiomyocytes form cytoplasmic grows or oblique anastomoses, connecting functional fibers (therefore, the heart works according to the law "All or Nothing").

6. For cardiac muscular fabric, a red muscles type is characteristic (see above)

7. There is no source of regeneration (there are no myostels), regeneration is due to the formation of a connective tissue scar at the place of lesion or compensatory hypertrophy.

8. Develops from the mioepcardial plate of visceral sheet of the splash.

Cardiac muscular fabric Forms middle shell (myocardium) atrial and ventricles of the heart and is represented by two varieties of working and conductive.

Working muscular fabric Consists of cardiomyocyte cells, the most important feature of which is the presence of perfect contact zones. Connecting with each other, the end ends, they form the structure similar to the muscle fiber. On the side surfaces, cardiomyocytes have branches. Connecting ends with the branches of neighboring cardiomyocytes, they form anastomosis. The boundaries between the ends of the adjacent cardiomyocytes are inserted discs with straight or stepped circuits. In the light microscope, they have the type of transverse dark strips. Using inserts and anastomoses, a single structural and functional contracting system is formed.

In electron microscopy, it was revealed that in the field of inserted disks, one cell is in the other finance protrusions, on the side surfaces of which are desmosomoms, which ensures high adhesion strength. At the ends of the finance protrusions, sling was found through which the nerve impulses quickly propagate from the cell to the cell without the participation of the mediator synchronizing the reduction of cardiomyocytes.

Cardiac myocytes are single-core, sometimes dual-core cells. The kernels are located in the center, in contrast to skeletal muscle fibers. In the near-door zone there are components of the Golgi, Mitochondria, Lizosomes, Glycogen Granules.

The contracting apparatus of myocytes, as well as in skeletal muscle tissue, consists of myofibrils that occupy the peripheral part of the cell. Their diameter from 1 to 3 microns.

Myofibrils are similar to the myofibrils of skeletal muscle tissue. They are also constructed from anisotropic and isotropic disks, which also causes transverse allocations.

The cardiomyocyte plasmolm at the level of the Z-strips is infant into the depth of the cytoplasm, forming transverse tubes, differing from skeletal muscle tissue with a large diameter and the presence of a basal membrane that covers them outside, as well as sarchatim. The depolarization waves, which come inside the cardiac myocytes with plasmolemma, cause the slip of actin miosin (Protofibril) in relation to myosinov, causing the reduction as in skeletal muscle tissue.

T-tubes in cardiac operating cardiomyocytes form Diaps, that is, connected with the tanks of the sarcoplasmic network only on the one hand. Working cardiomyocytes have a length of 50-120 μm, a width of 15-20 microns. The number of myofibrils in them is less than in muscle fibers.

Cardiac muscular fabric contains a lot of myoglobin, so dark red. In myocytes there are many mitochondria and glycogen, i.e.: The energy of the heart muscle tissue is obtained during the decay of ATP, and as a result of glycolysis. Thus, the heart muscle works continuously all his life due to powerful energy equipment.

The intensity and frequency of abbreviations of the heart muscle are regulated by nerve impulses.

In embryogenesis, working muscle tissue develops from special sections of visceral leaflet of non-elected mesoderm (splash). In the formed working muscle tissue of the heart there are no cambial cells (miosatellites), so when damaged myocardium in the injured zone, the cardiomyocytes die and fibrous connecting tissue develops at the injury.

Conductive muscular heart fabric It is located as part of a complex of formations of the sinus-atrial node, located at the mouth of the cranical hollow vein, the atrocadic assembly, lying in the interdestrian partition, the atrocadic trunk (Gis beam) and its branches under the endocardium of the interventricular partition and in the connecting beds Myocardium.

All components of this system are formed by atypical cells specialized either on the production of pulse spreading throughout the heart and causing a reduction in its departments in the required sequence (rhythm) or in a pulse to working cardiomyocytes.

For atypical myocytes, a significant amount of cytoplasm is characterized, in which few myofibrils occupy the peripheral part and do not have a parallel orientation, as a result of which these cells are not characterized by transverse aperture. The kernels are located in the center of the cells. The cytoplasm is rich in glycogen, but there are few mitochondria in it, which indicates intensive glycolize and low-level aerobic oxidation. Therefore, the cells of the conductive system are more resistant to oxygen starvation than contracting cardiomyocytes.

As part of the sinus-atrial node atypical cardiomyocytes smaller, rounded shape. Nervous impulses are formed in them and they relate to the main rhythm drivers. The myocytes of the atrocarditricular node is somewhat larger, and the fibers of the Gis beam (Purkinier fibers) consist of large rounded and oval myocytes with an eccentric nucleus. The diameter of them is 2-3 times more than workers cardiomyocytes. The electron microscopically revealed that in atypical miacites weak the sarcoplasmic network, there is no system T-tube. Cells are connected not only by ends, but also side surfaces. Insert discs are arranged easier and do not contain finger-shaped connections, despair and nexus.

Muscular fabricsthey are a group of tissues of various origin and structure combined on the basis of a general feature - a pronounced contractility, thanks to which they can perform their main function - move the body or part of it in space.

The most important properties of muscle tissues.The structural elements of muscle tissues (cells, fibers) have an extended form and are capable of reduced due to the powerful development of the contracting device. For the latter, a highly ordered location is characterized. aktinovand myosine myofilamentscreating optimal conditions for their interaction. This is achieved by the bond of reduced structures with special elements of the cytoskeleton and plasmolemma (Sarchatum),performing reference function. In terms of muscle tissues, myofilaments form organlelles of special meaning - miofibrils.For muscle reduction, a significant amount of energy is required, therefore, in structural elements of muscle tissues there is a large amount of mitochondria and trophic inclusions (lipid droplets, glycogen granules) containing substrates - energy sources. Since muscle contraction proceeds with calcium ions, in muscle cells and fibers, the structures exercising its accumulation and selection are well developed - agranular endoplasmic network. (Sarcoplasmatic network), Kavoola.

Classification of muscular fabricsbased on the signs of their structure and functions (Morphofunctional classification)and (b) origin (Histogenetic classification).

Morphofunctional classification of muscle tissues highlight cross-resistant (deshastable) muscle tissueand smooth muscular fabric.Transverse muscle tissues are formed by structural elements (cells, fibers), which have transverse allocations due to a special orderly interconnection of actin and aligning myophilaments in them. Related transverse muscular tissues skeletteand heart muscular fabric.Smooth muscular tissue consists of cells that do not have a cross-term. The most common type of this tissue is a smooth muscular fabric, which is part of the wall of various organs (bronchi, stomach, guts, uterine, uterine tube, ureter, bladder and vessels).

Histogenetic classification of muscle tissues highlight three main types of muscular fabrics: somatic(skeletal muscle tissue), nomichic(cardiac muscular tissue) and mesenchymna(Smooth muscular fabric of internal organs), as well as two additional: moepithelial cells(modified epithelial reduced cells in the end departments and small output ducts of some glands) and mioneral elements(Signal cells of neural origin in the eye iris).

Skeletal transverse (exhausted) muscular fabricby its mass exceeds any other tissue of the body and is the most common muscle tissue of the human body. It provides the movement of the body and its parts in the space and maintaining the posture (included in the locomotor unit), forms eye muscles, muscles of the oral cavity, language, pharynx, larynx. A similar structure has a slow visceral exhausted muscle tissue, which is found in the upper third of the esophagus, is part of the exterior anal and urethral sphincters.

Skeletal transverse muscle tissue develops in the embryonic period from miotomovcoming, giving rise to actively divided myoblastam- cells that are located chain and merge with each other in the field of ends with education muscular tubes (Mitubule)transformed by B. muscular fibers.Such structures formed by a single giant cytoplasm and numerous nuclei, in domestic literature traditionally called simplists(in this case - myosimplestami)however, this term is absent in the adopted international terminology. Some myoblasts do not merge with others, located on the surface of the fibers and giving the beginning miosatellitzites- small cells that are cambial elements of skeletal muscle tissue. Skeletal muscle tissue is formed collected in bundles transverse muscle fibers(Fig. 87), which are its structural and functional units.

Muscular fibers skeletal muscle tissue is cylindrical formation of a variable length (from millimeters to 10-30 cm). Their diameter varies widely depending on the belonging to a certain muscle and type, functional state, the degree of functional load, the state of the power supply

and other factors. In the muscles, muscle fibers form beams in which they lie in parallel and, deforming each other, often acquire an incorrect multifaceted form, which is especially clearly visible on transverse sections (see Fig. 87). Between muscle fibers there are thin layers of loose fiber junction tissue, carrier vessels and nerves - endomise.Cross-term desecution of skeletal muscle fibers due to the alternation of dark anisotropic disks (bands a)and light isotropic disks (stripsI). Each isotropic disk dissects in thin dark lini Z - Balfragm(Fig. 88). Muscular fiber cores are relatively bright, with 1-2 nuclei, diploid, oval, flattened - lie on its periphery under the sarchatum and are located along the fiber. Outside the sarchatum is covered with thick basal membrane,in which reticular fibers come into.

Miosatellitocytes (mios cells) - Small flattened cells located in shallow presses of the muscle fiber sarchatimm and covered with a common basal membrane (see Fig. 88). The core of myosatellitocyte is dense, relatively large, organelles are small and few. These cells are activated in damage to muscle fibers and ensure their reparative regeneration. Merging with the rest of the fiber at reinforced load, myosatellocytes are involved in its hypertrophy.

Miofibrils they form a contracting device of muscle fiber, arranged in sarcoplasm at its length, occupying the central part, and is clearly detected on transverse sections of the fibers in the form of small points (see Fig. 87 and 88).

Myofibrillas have their own transverse allocations, and in muscle fiber they are located so much ordered that the isotropic and anisotropic disks of different myofibrill coincide among themselves, caused by the transverse allocation of the entire fiber. Each myofibrill is formed by thousands of repeating consistently interconnected structures - sarcomers.

Sarcomer (Miomer)it is a structural and functional unit of myofibrils and represents its site located between two bulfragmami (z lines).It includes an anisotropic disk and two halves of isotropic disks - one half of each side (Fig. 89). Sarcomer is formed by an ordered system thick (mosic)and thin (acts) of myofilaments.Thick myophilaments are associated with mezophragm (line M)and focused in an anisotropic disk,

and thin myophilaments are attached to balphragmam (z lines),form isotropic discs and partially penetrate into an anisotropic disk between thick threads up to light strip N.in the center of anisotropic disk.

Muscular abbreviation mechanism describes the theory of sliding threadsaccording to which the shortening of each sarcomer (A, consequently, myofibrils and all muscle fibers) occurs due to the fact that as a result of the interaction of actin and alone in the presence of calcium and ATP, thin threads are moved into the gaps between thick without changing their length. In this case, the width of the anisotropic disks does not change, and the width of the isotropic disks and the bands of N - decreases. The strict spatial orderliness of the interaction of a plurality of thick and thin myophilaments in the sarcomer is determined by the presence of a complexly organized supporting device to which, in particular, belongs to the belief and mezofragma. Calcium stands out from sarcoplasmic networkthe elements of which are powered by each myofibrill, after receipt of the signal from Sarchatim T-tubes(the totality of these elements is described as sarcotubular system).

Skeletal muscle as an organ it consists of muscle beams associated with the system of connective tissue components together (Fig. 90). Outside the muscle covers epimizius- Thin, durable and smooth covers of thick fibrous connective tissue, glowing the body of more subtle connecting partitions - perimisiawhich surrounds the bunches of muscular fibers. From permias, the subtlest layers of loose fiber junction tissue, surrounding each muscular fiber - endomise.

Types of muscle fibers in a skeletal muscle - varieties of muscle fibers with certain structural, biochemical and functional differences. Typing muscle fibers is made on preparations when setting histochemical reactions of detection of enzymes - for example, ATPase, lactate dehydrogenase (LDH), succinate dehydrogenase (SDH) (Fig. 91) and others. In general, it is possible to conditionally distinguish three main types of muscle fibers, between which there are transitional Options.

Type I (red)- Slow, tonic, resistant to fatigue, with a small reduction force, oxidative. Characterized by a small diameter, relatively thin myofibrils,

the high activity of oxidative enzymes (for example, SDH), low activity of glycolithic enzymes and the mosic atphase, the predominance of aerobic processes, a high content of Mioglobin pigment (determining their red color), large mitochondria and lipid inclusions rich in blood supply. Numerically prevail in the muscles performing long-term tonic loads.

Type IIB (White)- Fast, totanic, easily tightened, with great reduction force, glycolithic. Characterized by a large diameter, large and strong myofibrils, high activity of glycolytic enzymes (for example, LDH) and ATPase, low activity of oxidative enzymes, the predominance of anaerobic processes, a relatively low content of small mitochondria, lipids and myoglobin (defining their light color), considerable amount of glycogen, Comparatively weak blood supply. They prevail in the muscles performing rapid movements, such as muscles of the limbs.

Type IIA (intermediate)- Fast, resistant to fatigue, with great strength, oxigative-glycolithic. On the preparations resemble the fibers of type I. A equally capable of using the energy obtained by oxidative and glycolithic reactions. According to its morphological and functional characteristics, the position is occupied, intermediate between the fibers of type I and IIb.

Skeletal muscles of a person are mixed, i.e. contain fibers of various types that are distributed in them mosaic (see Fig. 91).

Cardiac transverse (acheuta) muscular fabricit is found in the muscular shell of the heart (myocardium) and the mouths of large vessels associated with it. The main functional property of heart muscle tissue is the ability to spontaneous rhythmic contractions, which affect the hormones and the nervous system. This tissue provides heart cuts that support blood circulation in the body. The source of the development of cardiac muscular fabric serves mioPicardial Plate Visceral Licketer Slane(Organic chipping in the neck of the embryo). Cells of this plate (myoblasts) are actively multiplied and gradually turn into cardiac muscular cells - cardiomyocytes (hearty myocytes).Laying in chains, cardiomyocytes form complex intercellular compounds - insert discsbinding them in heart muscular fibers.

Mature hearty muscular tissue is formed by cells - cardiomyocytes,associated with each other in the field of inserts and forming a three-dimensional network of branching and anastomosing heart muscular fibers(Fig. 92).

Cardiomyocytes (hearty myocytes) - Cylindrical or branching cells, larger in ventricles. In atria, they usually have a wrong form and smaller sizes. These cells contain one or two nuclei and sarcoplasm, covered with sarchatum, which is surrounded by a basal membrane. Their kernels are bright, with the predominance of eukhromatin, well-visible nucleists - occupy a central position in the cage. In an adult, a significant part of cardiomyocytes - polyploidmore than half - double.Cardiomyocyte sarcoplasma contains numerous organelles and inclusions, in particular, a powerful contractual apparatus, which is strongly developed in contractile (working) cardiomyocytes (especially in ventricular). The contractile apparatus is presented heartfelt stuffed myofibrilsin the structure of fibers of skeletal muscle tissue similar to the miofibrils (see Fig. 94); In the aggregate, they determine the transverse allocations of cardiomyocytes.

There are very numerous and large mitochondria (see Fig. 93 and 94) between Miofibrils. Myofibrils are surrounded by elements of a sarcoplasmic network associated with T-tubes (see Fig. 94). Cardiomyocyte cytoplasm contains oxygen-binding pigment of myoglobin and accumulation of energy substrates in the form of lipid droplets and glycogen granules (see Fig. 94).

Types of cardiomyocyte in the heart muscle tissue, they differ in structural and functional signs, biological role and topography. There are three main types of cardiomyocytes (see Fig. 93):

1)contractile (working) cardiomyocytesform the main part of the myocardium and are characterized by a powerfully developed contractile apparatus, which occupies the most sarcoplasma;

2)current cardiomyocyteshave the ability to generate and rapid electrical impulses. They form nodes, bundles and fibers conductive system of heartand divided into several subtypes. Characterized by the weak development of the contractile apparatus, light sarcoplasma and large nuclei. IN conductive heart fibers(Purkinje) These cells have large sizes (see Fig. 93).

3)secretor (endocrine) cardiomyocyteslocated in the atriums (especially

vOM) and are characterized by a processful form and a weak development of the contractile apparatus. In their sarcoplasma near the poles of the kernel there are surrounded membranes dense granules containing atrial sodretetic peptide(hormone, causing sodium loss and water with urine, extension of vessels, decrease in blood pressure).

Insert discs correction of cardiomyocytes with each other. Under the light microscope, they have the form of transverse direct or zigzag strips crossing the heart muscle fiber (see Fig. 92). The electron microscope is determined by the complex organization of the insertion disk, which is a complex of intercellular compounds of several types (see Fig. 94). In the field of transverse (oriented perpendicular location of myofibrils) sections of inserting disk, adjacent cardiomyocytes form numerous interdigations associated with contacts such as desmosomomand adhesive fascia.Actin Filaments are attached to the transverse sections of the inserted disk sarchatrols at the level lines Z.On the Sarchatum of the longitudinal sections of the inserted disk there are numerous slitual compounds (Nexus),providing ionic communication of cardiomyocytes and transmission of a reduction impulse.

Smooth muscular fabricit is part of the wall of hollow (tubular) internal organs - bronchi, stomach, guts, uterine, uterine pipes, ureters, bladder bladder (visceral smooth muscular fabric),as well as vessels (vascular smooth muscular tissue).Smooth muscular fabric is also found in the skin, where it forms muscles, lifting hair, in capsules and trabecules of some organs (spleen, ich). Due to the contractile activity of this tissue, the activity of the digestive tract, the regulation of respiration, blood and lymphotok, the separation of urine, the transport of genital cells, etc. The source of the development of smooth muscle tissue in the embryo is mesenchym.The properties of smooth myocytes also have some cells with a different origin - moepithelial cells(modified contractile epithelial cells in some glands) and mioneral cellsiris eye (develop from neural primarily). The structural and functional unit of smooth muscle tissue serves smooth myocyt (smooth muscular cell).

Smooth myocytes (smooth muscle cells) - elongated cells preferably

teanoid shapes that do not possess transverse aperture and forming numerous connections with each other (Fig. 95-97). Sarchatimmaeach smooth myocyte is surrounded basal membrane,in which thin reticular, collagen and elastic fibers are intertwined. Smooth myocytes contain one extended diploid core with the predominance of eukhromatin and 1-2 nuclei, located in the central thickened part of the cell. In the sarcoplasm of smooth myocytes, moderately developed organizations of the total value are located together with the inclusions in the cone-shaped sections of the core poles. Its peripheral part is occupied by a contracting device - aktinovand myosine myofilamentswhich in smooth myocytes do not form myofibrils. Actin myophilaments are attached to sarcoplasm to oval or spindle-shaped dense tanks(see Fig. 97) - structures, homologous lines Z in transverse tissues; similarities associated with the inner surface of the Sarchatomma are called dense plates.

The reduction in smooth myocytes is ensured by the interaction of myophilaments and develops in accordance with the model of sliding threads. As in transverse muscle tissues, the reduction of smooth myocytes is induced by the influx of Ca 2+ in a sarcoplasm, which in these cells is highlighted sarcoplasmic networkand caveolami- numerous flask-shaped phenomena of the Sarchatim surface. Due to the pronounced synthetic activity, smooth myocytes produce and isolated (like fibroblasts) collagen, elastin and components of an amorphous substance. They are also able to synthesize and secrete a number of growth factors and cytokines.

Smooth muscular fabric in organs usually represented by layers, bundles and layers of smooth myocytes (see Fig. 95), inside which cells are associated with interdigations, adhesive and slotted connections. The location of smooth myocytes in the formation is such that the narrow part of one cell arrives to a wide part of the other. This contributes to the most compact laying of myocytes, ensuring the maximum area of \u200b\u200btheir mutual contacts and high tissue strength. Due to the described arrangement of smooth muscle cells in a reservoir on transverse sections, the cross sections of myocytes cut in a wide part and in the narrow edge region are adjacent (see Fig. 95).

Muscular fabrics

Fig. 87. Skeletal transverse muscle tissue

1 - muscle fiber: 1.1 - Sarchatimm, coated with a basal membrane, 1.2 - sarcoplasma, 1.2.1 - Miofibrils, 1.2.2 - Fields of Miofibrils (Congeim); 1.3 - muscular fiber cores; 2 - endomisia; 3 - layers of loose fibrous connective tissue between the bunches of muscle fibers: 3.1 - blood vessels, 3.2 - fat cells

Fig. 88. Skeletal muscle fiber (diagram):

1 - basal membrane; 2 - Sarchatim; 3 - Miosatellitocyte; 4 - core of myosimplast; 5 - isotropic drive: 5.1 - BELFRAGMA; 6 - anisotropic disk; 7 - Miofibrils

Fig. 89. Plot Miofibrils of skeletal muscle tissue fiber (Sarcomer)

Figure with EMF

1 - Isotropic disk: 1.1 - Thin (Aktin) Miofilaments, 1.2 - Belfragma; 2 - anisotropic disk: 2.1 - thick (mosinic) myophilaments, 2.2 - mezofragma, 2.3 - strip H; 3 - Sarcomer

Fig. 90. Skeletal muscle (cross-section)

Color: Hematoksilin-Eosin

1 - epimizios; 2 - perimisia: 2.1 - blood vessels; 3 - Muscular Fiber Bundles: 3.1 - Muscular Fibers, 3.2 - Endomisia: 3.2.1 - Blood vessels

Fig. 91. Types of muscle fibers (cross-cut skeletal muscle)

Histochemical reaction to the detection of succinate dehydrogenase (SDH)

1 - type I fibers (red fibers) - with high SDH activity (slow, oxidative, resistant to fatigue); 2 - Type (white fiber) fibers - with low SDH activity (fast, glycolithic, tired); 3 - type II (intermediate fiber) - with moderate activity of SDH (fast, oxidative and glycolithic, resistant to fatigue)

Fig. 92. Cardiac transverse muscle tissue

Coloring: Iron Hematoxylin

A - longitudinal cut; B - transverse cut:

1 - cardiomyocytes (form hearted muscle fibers): 1.1 - Sarchatimma, 1.2 - sarcoplasma, 1.2.1 - Miofibrils, 1.3 - core; 2 - insert discs; 3 - anastomoses between the fibers; 4 - loose fibrous connecting fabric: 4.1 - blood vessels

Fig. 93. Ultrastructural organization of cardiomyocytes of various types

Figures with EMF

A - contractile (worker) Heart ventricular cardiomyocyst:

1 - basal membrane; 2 - Sarchatim; 3 - sarcoplasma: 3.1 - Miofibrils, 3.2 - mitochondria, 3.3 - lipid drops; 4 - core; 5 - insert disk.

B - cardiomyocyte conducting heart system (from subendocardial network fibers Purkinier):

1 - basal membrane; 2 - Sarchatim; 3 - sarcoplasma: 3.1 - Miofibrillas, 3.2 - mitochondria; 3.3 - glycogen granules, 3.4 - intermediate filaments; 4 - kernels; 5 - insert disk.

B - endocrine cardiomyocyte from atrium:

1 - basal membrane; 2 - Sarchatim; 3 - sarcoplasma: 3.1 - Miofibrillas, 3.2 - mitochondria, 3.3 - secretory granules; 4 - core; 5 - insert disk

Fig. 94. Ultrastructural organization of the field of inserted disk between adjacent cardiomyocytes

Figure with EMF

1 - basal membrane; 2 - Sarchatim; 3 - sarcoplasma: 3.1 - Miofibrillas, 3.1.1 - Sarcomer, 3.1.2 - isotropic disk, 3.1.3 - anisotropic disk, 3.1.4 - bright strip H, 3.1.5 - Belfragma, 3.1.6 - Mesofragma, 3.2 - mitochondria, 3.3 - T-tube, 3.4 - elements of the sarcoplasmic network, 3.5 - lipid drops, 3.6 - glycogen granules; 4 - Insert Disc: 4.1 - InterDigations, 4.2 - Adhesive Fascia, 4.3 - Desmosoma, 4.4 - Slitual Connection (Nexus)

Fig. 95. Smooth muscular fabric

Color: Hematoksilin-Eosin

A - longitudinal cut; B - transverse cut:

1 - Smooth myocytes: 1.1 - Sarchatimma, 1.2 - sarcoplasma, 1.3 - core; 2 - layers of loose fibrous connective tissue between beams of smooth myocytes: 2.1 - blood vessels

Fig. 96. Isolated smooth muscular cells

Color: Gematoksilin

1 - core; 2 - sarcoplasma; 3 - Sarchatimma

Fig. 97. Ultrastructural organization of the smooth myocyte (plot of cells)

Figure with EMF

1 - Sarchatim; 2 - sarcoplasma: 2.1 - mitochondria, 2.2 - dense taurus; 3 - core; 4 - Basal Membrane

Cardiac muscular fabric - section Agriculture, anatomy and histology of agricultural animals This fabric forms one of the layers of the heart wall - myocardium. She is.

This fabric forms one of the layers of the heart wall - myocardium.

Fig. 66. The scheme of the structure of cardiac muscular fabric:

1 - muscle fiber; 2 - insert discs; 3 - core; 4 - layer of loose connective tissue; 5 - transverse cut of muscle fiber; a - kernel; B - Bundles Miofibrils located on radius.

Actually cardiac, muscle The fabric in its physiological properties occupies an intermediate position between the smooth muscles of internal organs and transverse (skeletal). It is reduced faster smooth, but slower transverse muscles, it works rhythmically and is tires little. In this regard, in its structure there are a number of peculiar features (Fig. 66). This fabric is made of individual muscle cells (myocytes), almost rectangular shapes located on each other. In general, it turns out a structure resembling transverse fiber, divided into segments by transverse partitions - insert discs We are areas of plasmamama of two neighboring cells in contact with each other. Next lying fibers are connected by anastomoses, which allows them to decline simultaneously. Muscular fiber groups are surrounded by connecting interlayers like endomise. In the center of each cell 1-2 cores of oval form. Myofibrils are located along the periphery of the cells and have transverse aperture. Between myofibrils in sarcoplasma a large number of mitochondria (Sarkos), extremely rich in cristles, which speaks of their high energy activity. Outside the cell is covered, except for plasmalama, also the basal membrane. Wealth cytoplasm and well-developed trophic apparatus provide the heart muscle continuity of activity.

Conductive system The heart consists of poor museum of muscle tissue, capable of coordinating the work of the separated muscles of ventricles and atrial.

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1. Bone system. Skeleton as a system of movement and supports. Types of combination of bones, battle and joints. The relative mass of the skeleton bones in the body of animals and meat tutes. 2.

To facilitate the study of the body of the animal body through the body, several imaginary planes are carried out. Sagittal plane, spent vertically along the body of the animal

The anatomy section, which studies the bones is called osteology (from the lat. Osteon - bone, Logos - doctrine). The skeleton consists mainly of bones, as well as from cartilage and ligaments.

The bones of the skeleton are interconnected with varying degrees of mobility. 1 Continuous - synartrosis - the battle of two bones through various fabrics with education

The whole life of the animal is associated with the function of movement. In the implementation of the motor function, the main role belongs to skeletal muscles, which are the working bodies of the nervous system.

The muscle has a tendon head, a belly and a tendon tail. Skeletal muscles depending on the function being performed differ from each other by the ratio of muscle beams and connective kits

To the auxiliary devices and muscle organs include: 1. Fascia - cover muscles, playing the role of cases, ensure the best conditions for movement, facilitate blood and

1. The patterns of the structure, location and function of the internalities. The concept of body cavities. 2. General characteristics of system of digestive, respiration, uriction and multiplied

Internally systems are compacted from hollow, pipes and compact organs. Tube organs. Despite sharp differences in the structure depending on the function, labor

Blood is a specific fluid, the necessary life environment for all cells, tissues and organs of multicellular organisms. To maintain the metabolism in cells, blood brings and

The nervous system is of great importance in the life of living organisms, ensuring the relationship between all body bodies, adjusting their functions and adapting the body to the changing conditions of the environment

Internal secretion. The glands of the internal secretion (endocrine), in contrast to conventional glands, do not have output ducts, and distinguish the substances formed in them - hormones in the blood

All mammals and birds have a constant body temperature, independent of ambient temperature. The ability of the body to maintain a constant body temperature with changing temperatures

The diverse interaction of the outside world is perceived by the senses, thanks to which the body's connection with the environment is carried out. However, there are specific analysis

1. irritation of the analyzer receptors with adequate stimuli (wands of the eye - light); 2. Generation of receptor potential; 3. Pulse transmission to the nervous cell and generation in

Receptor devices of sense organs have a number of common properties. 1. High sensitivity to adequate stimuli (i.e. specifically

In mammals (eyeballs) are located in the deepening of the bones of the skull - the eye and are close to the ball. The eye consists of: - optical parts

Light rays before entering the retina photoreceptors, undergo a number of refractions, because Pass through the cornea, crystal and the vitreous body. Refraction of rays when moving

Man and animal should well and clearly see objects deleted at different distance. The ability of the eye clearly see the distant items is called accommodation.

Mesh shell is an important component of the eye, located between the vitreous body and the vascular sheath. It is the basis of the support cells forming the structure

Colorful eyesight is of great importance in the life of animals: - improves the visibility of objects; - increases the completeness of the presentation of them; - Promotes best

In the process of evolution, animals have formed an organ that perceives and analyzing sound oscillations is an auditory analyzer. In mammals, the auditory apparatus is divided into three

1. Sound oscillations are captured by the ear shell and are transmitted through the outer auditory passage to the eardrum. 2. The eardrum begins to fluctuate with the frequency corresponding to

Air conduction is carried out in the range: a person from 16 DOGC (oscillations in 1 s), dogs - 38 - 80,000, sheep - 20 - 20,000, horses - 1000 - 1025. Human speech sounds with

The smell is a complex process of perceiving odors with a special body. In animals, the sense of smell plays a very important role in the process of searching for food, stall, nests, sexual partner. Perifer

The taste analyzer informs the animal about the amount and quality of different feed substances. The receptor cells of the analyzer of taste are located in the mucous membrane of the papillars of the language that have fungus

The signals about the ambient temperature organism gets from thermistors. Thermoreceptors are divided into two groups: - coolness - are located superficially; - Heat faces

This sensitivity is due to the irritation of special receptors located in the skin at some distance from each other. The perception of two points separately determines the threshold of the tactile sensitivity.

Pain is an unconditional reflector protective reaction that provides information on the proceedable changes in the function of organs and tissues. The feeling of pain is formed in the cerebral cells head

The classification of receptors on extero, inter-and proproporeceptors is rather morphological character, they are functionally related to each other. So, the hearing body is functionally interacting with

The skin of birds has, like the skin of mammals, epidermis, the base of the skin and the subcutaneous layer. However, in the skin of birds there are no sweat and sebaceous glands, but there is a special cork iron,

The system of respiratory organs of birds is characterized by changing the structure of some organs and is complemented by special air bags (Fig. 21).

The genital organs of males consist of semennikov, appendages of seeds, seedworks and some birds from a peculiar penis (Fig. 23). Added sex glands in birds

Bird heart four-chamber; It differs from the heart of mammals by the fact that in the right ventricle there are no nobble muscles and an atrioventricular valve. The latter is replaced by a special muscle plate coming

Features of the nervous system and senses. The spinal cord of the birds is generally similar to the spinal cord of mammals, but ends with a short terminal thread. In the middle brain instead of four twoly

The technological raw material of the meat industry is the various organs of the animal. The modern processing industry is capable of turning into a useful product of the national economy.

The cell is a self-regulating elementary, live system, which is part of the tissue and subordinate to the highest regulatory systems of a holistic organism. Each K.

The endoplasmic network is a system of anastomosing (related) with each other by tubules or tanks located in deep layers of cells. Diameter of bubbles and tanks

This organoid received its name in honor of the scientist K. Goldzhi, who for the first time in 1898 saw and described it. In animal cells, this organoid has an extensive mesh structure and considerable

Cells of some tissues due to the characteristics of their functions, besides these organelles, have special organelles that provide a cell to the specifics of its functions. Such organelles represent

Cellular inclusions are temporary accumulations of any substances arising in some cells in the process of their livelihoods. Inclusions have a kind of fucking droplets

The fertilized egg in the process of its division (crushing) and development turns into a complex multicellular body. In the course of development, some cells under the influence of genetically

Fabrics do not remain unchanged after they acquired the features specific for them. They constantly commit processes of development and adaptation to continuously changing external conditions.

Epithelial tissue (or epithelium) develops from all three embryonic sheets. The epithelium is located near vertebrates and man on the surface of the body, wipes all the hollow

The cells of this epithelium have the ability to synthesize special substances - secrets, the composition of which are not the same at different glands. Properties of secretion possess both individual cells and complex MN

The support and trophic fabrics form the frame (stroma) of the organs, carry out the organ trophic, carry a protective and reference function. Reference-trophic fabrics include blood, lymph

According to the degrees of ordering and predominance of certain tissue elements, the following connecting fabrics are distinguished: 1. loose fibrous - distributed in the body everywhere, with

Three types of cartilage distinguish: hyaline, elastic, fibrous. All of them originated from mesenchym and have a similar structure, the overall function (support) and take part in carbohydrate exchange. H.

The bone tissue is formed from the mesenchyma and develops in two ways: directly from the mesenchyma or in the place of previously laid down cartilage. In bone tissue distinguish cells and an intercellular substance.

Muscular fabrics are divided into: smooth, skeletal and cordial transverse. The general sign of the structure of muscle tissues is the presence of reduced elements in the cytoplasm

Nervous tissue consists of neurons and neuroglia. The main embryonic source of the nervous tissue is the nervous tube, depicted from the ectoderma. The main functional unit of nervous tissue I

General characteristic. This group includes tissues that can cause a motor effect either in separate organs (heart, intestines, etc.), or the entire animal in space.

A muscular layer of walls of all bandwidth internal organs is built from the smooth muscular fabric, it is also in the walls of blood vessels and in the skin. This fabric is reduced relatively slowly, d

From this type of fabric, the whole somatic, or skeletal, musculatura of mammals, as well as muscles of the language, muscles, leading the eyeball, the muscles of the larynx and some others are constructed. Across

After slaughtering an animal metabolism, characteristic of the living organism, stops. Not all organs and complex systems of the body are dying after slaughter. Many, normally not functioning, engage in special

Steam meat is the initial control structure with which you can compare all subsequent changes in meat, exposed to further technological processing. Microscopic analysis

Use in theory and practice of histological studies of comparative changes occurring in steam and chilled meat can contribute to the intensification and improvement of the modes

In 1970, N. P. Yanushkin and I. A. Lagosha found that when storing chilled meat, the formation of a crust of dried in surface layers of carcass and bran in

Meat freezing is a complex process. Its stroke largely depends on the duration of the period last after the slaughter of animals, from temperature and topographically

Skeletal transverse muscle muscle fibers of domestic birds can be determined by the nuclei that lie not under the sarchatum, but in the depths of sarcoplasm, and by the presence of oval erythrocytes in the vessels

When conducting various studies, it is often necessary to know the size of muscle fibers in different cuts of meat or in separate muscles. But the accurate information is still very small, and they are not systematized. IN

The quality of meat (tenderness, taste) is largely depends on the content of connective tissue in the muscles. In the finest layers, the endomise between the individual fibers are found mainly

Ambassador. Under the arrangement of an ordinary stationary way (20% brine) in samples of meat (the long muscles of the back of the pig) transverse and longitudinal allocations are well preserved after 6

The skin, which is the outer cover of the body of animals, consists of three layers - superficial (epidermis), actually skin (dermis) and subcutaneous layer. Cells of surface

The skin develops from ectoderma and mesenchym. Ektoderma gives the beginning of the outer layer of the skin, or the epidermis (Fig. 49, a, b, b, s), and the mesenchym produced by dermatomas - in

The epidermis is represented by a multi-layered flat epithelium of the unequal thickness in different places; It is especially significant for its reservoir in the hairless places of the skin (Fig. 49).

Cleaning, shot from the animal, is called the skin. The skin released during the isoiced from the subcutaneous layer is called fur, and the skin liberated from the epidermis. Most major

In the small intestine, the processes of digestion and nutrient materials are being absorbed into the blood and lymphatic channel. These physiological properties are reflected in the structure of the small intestine:

In pots, digestive processes play a much smaller role than thin; There is intensive suction, mainly water and minerals, as well as

Livestock is an important branch of agriculture, providing the population with a variety of food products, and the light industry - raw materials. Milk, meat, eggs

The Constitution is a combination of anatomical and physiological features of the animal associated with the nature of productivity. In the history of animal husbandry, there was a lot of attempts to develop

Studying the basics of anatomy and physiology of animals can be concluded that animal reaction on the environment, and therefore their productivity, fertility, disease resistance and many

The creation of animals of the desired type is possible only when taking into account the patterns of individual development, accounting for the factors affecting the cultivation of young people. Individual development

For the growth and development of agricultural animals, unevenness and frequency are characteristic. Agricultural animals most of them belong to the highest mammal, he

Cropon breeding - the pairing of animals of one breed is used in breeding farms, in dairy farms, in many sheep farms, on poultry farms

Modern intensive animal management methods are designed for the maximum use of all potential animal capabilities: obtaining the maximum amount of products for the minimum

Meat productivity is concluded by the morphological and physiological features of animals. These features are formed and developed under the influence of heredity, Cormal conditions

Of all environmental factors, the strongest influence on animal productivity has feeding. From feed Animal gets structural material for constructing fabric, energy and substance, reg

Feed feed is a property to satisfy the natural needs of the animal. It depends on the chemical composition of the feed. A significant part of most feed is water (Fig. 18).

Under the nutability of the feed understand the property of the latter to satisfy the natural requirements of animals in food. Feed feed nutrition in their chemical composition, content in them

For normal growth, animals must necessarily obtain with food so-called indispensable amino acids: lysine, tryptophan, leucine, isoleucine, phenylalanine, threonine, methionine, valine, arginine. Name

The most demanding about the flow of full-fledged protein growing and adult animals with high productivity. The lack of some amino acids in some feed can be replenished by

Vitamins - biologically active organic compounds necessary for the vital functions of the body. The absence or disadvantage in the feed of one vitamin causes severe illness in animals

Almost all chemical elements found in nature are found in the body of animals. Depending on the quantity they are divided into macroelements (calcium, phosphorus, magnesium, potassium, sodium, gray

Green food green feed - that the grass of natural meadows and specially cultivated for the needs of animal husbandry. An important biological value of grass is explained by the wealth of proteins,

Waste of dairy, meat and fishing industry contains many proteins of high biological value, minerals and vitamins. Fogged basically young

The mixture of dried and crushed feeds, composed of scientifically substantiated recipes, is customary with feed. There are in crumbly, granulated and briquetted form. Distinguish K.

For full feeding of animals, mineral feed is needed, so-called additives. The table salt is used for all animals as a source of sodium and chlorine, which not

Cattle is better than other animal species, digesting feed with high fiber content. Due to the synthesis of amino acids in the forefronts as a result of microorganis

Stomach ruminant complex, multi-chamber. It is an example of an evolutionary adaptation of animals to consumption and digesting large quantities of vegetation feed. Such animals are called

Gastric juice - a colorless liquid of an acidic reaction (pH \u003d 0.8-1.2), containing organic and inorganic substances. Na, K, MG, HCO inorganic substances

The Dutch breed is the most ancient and most expensive breed, created, according to most researchers, without the adherte of other breeds. According to P. N.

Simmental breed. Motherland of Simmental cattle - Switzerland. There is no consensus about his origin, however, it is known that over the past few centuries this cattle times

To increase the meat production in the country, fattening cattle has great importance. With the right organization of fattening animals, the cost of meat is reduced, and the meat cattle breeding becomes high

Food is fattening livestocks on natural pasture grounds. In the deep districts of Kazakhstan, Siberia, Lower Volga region, Transcaucasia, the North Caucasus, the Far East, the Urals have large areas

High productivity can be obtained only from breed animals adapted to a specific climatic zone and feed conditions. All breeds in the direction of productivity are divided into

Indicators Productivity Number of supports from 1 sows per year 2.0-2.2 multi-flow sows, goal

When setting a pig on fattening, you need to pay attention to its breed, health and development. Special attention deserves the state of the lungs. With their damage, the pig is breathing hard, often,

Meat fattening is the main type of fattening of most of the sweeps (from 3-4 to 6-8 months of age on achievement). With meat fattening, the average daily increase in the beginning

Breed. Pigs of domestic and most foreign rocks, as well as their penetration, with intensive fattening to the 6.5-8-monthly age reaches a live masskg during costs

All feed on the effect on the quality of meat and sludge is divided into three groups. First group. This grain feed, contributing to the production of high quality pork - barley, wheat, rye, mountain

Its selection can be different and depends on the demand of the population on the pork of different varieties, from market prices for it and the possibility of obtaining one or another pork in the calculation of one animal. IN

Before the fence, the pigs are stopped feeding in 12 hours, water gives water. Kill a pig better in a limp condition, without prior stun. After hanging with a sharp narrow knife

A significant place in the meat balance is occupied by lamb. One of its valuable features is the smallest cholesterol content compared to other animal meat. Economically

In the farms involved in the breeding of sheep, the year begins with the preparation of casemate for the concern. Most rocks are hunting in the afternoon. Only the sheep of the Romanov breed are capable of

The fine direction of productivity Soviet Merinos (coat-meat, fine). The breed has a complex origin. In her formation

In the Belgorod region, you can breed a sheep of various breeds: everything will depend on what they want to get. If the farm wants to get good quality lamb and white wool suitable for

An important branch of productive animal husbandry is sheep. By the amount of breeds and variety of products, it exceeds other industries. Wool, fur coat and fur sheepskin were

Pasture period. The sheep can be translated into pasture content in our field in the second half of April - early May. At the same time during the first 5-7 days before the pasture on Pa

Although the entire period of imagination lasts 5 months, the first three months the need for nutrients in the developing fetus is small, therefore, if there is good pasture herbs, an additional subcooked

Homemade chickens, chicken detachments, the most common type of agricultural bird. There were about 5 thousand years ago from the wild Bancake chickens (Gallus Bankiva) taught in India. Character

Poultry products include egg, meat, fluff, pen, as well as litter, used as valuable fertilizer. Egg is one of the most valuable foods. In nutability 1 egg

Young birds can be obtained from under the hut or by artificial egg incubation. The duration of the extension of eggs: chicken, duck, turkey, goose, musky ducks -

The success of growing meat chickens (broilers) significantly depends on the breeding qualities of the chickens. In 2 months of age, meat chickens with proper feeding and content have a living mass of more than 1.5 kg.

Geese differ in high growth intensity. The back of their weight increases the enemy and reaches 4 kg or more. From a carcass 1 goose you can remove up to 300 g of the pen, including 60 g of the fluff. Feather and Pooh GU

Poultry feed is conditionally divided into carbohydrate (all cereals, of juicy - potatoes, beets, from technical waste - bran, melasse, fum); Protein (animal origin -

Chickens should be fed immediately after they descend, but preferably no later than 8-12 hours after hatching. Weak chicks feed with a pipette with a mixture of chicken

The diet for chickens should consist of whole grains and a flour mixture consisting of vegetable animal feed and mineral origin. The adult bird is fed 3-4 times a day. In the morning yes

It is necessary to feed geese with such a calculation so that in the spring during the reproduction period they had good fatness. For feeding geussy in the first days of life, moistened mixers of boiled eggs are prepared, Ze

Homemade ducks have a good appetite, energetic digestion. They with great success use extensive sudden walkways and especially small reservoirs, where in large numbers they eat various

In the spring with the appearance of greens to the very late autumn, the indeek should be scattered on pastures. Even in winter, when the weather is favorable, the turkeys need to walk away. Turks on pasture eat significant count

Chickens Egg breeds are very movable, have a small mass, lightbounds, dense plumage, well-developed comb and earrings. The bird weight does not exceed 1.7-1.9 kg (chickens). They are good feeding

Significantly higher productivity of individual lines and crossings. Crossing males of one line with females, the other and on the contrary, get crosses. The results of the crossing are verified on the combination of lines by Kachev

For this direction, not only actually meat productivity (feed cost per unit of production, strength), but also an increased egg production (the number of broiler chickens obtained from

Chickens of egg-meat breeds have always been distinguished by viability, good adaptability to local conditions, significantly exceeding egg breeds with live weight and mass of eggs, which justifies some

Peking. This is one of the most common meat breeds, bred by the poultry of China more than three hundred years ago. Beijing ducks are hardy, well tolerate harsh winters, their VP

Holmogorskaya. This is one of the leading domestic breeds of geese. Over the color of the plumage, white and gray varieties are more common. Goose eggs start up to

North Caucasian. Valid in the Stavropol Territory by crossing local bronze trials with broad bronze broadcasts. The torso is massive, wide front, to the tail

Broiler (English Broiler, from Broil - fry on fire), meat chicken, characterized intense p

Before the poultry is needed some preparation that will prevent a quick damping of the carcass. First of all, it is necessary to clean the gastrointestinal tract from food residues. For this chickens, ducks and

1. Khrustaleva I.V., Mikhailov N.V., Schneiberg N. I., and others. Pet Anatomy: Tutorial Publishing House. 4th, corrected and complemented. M.: Kolos, 1994.s. 2. Ekkin V.F., Sidorova M.V. MO

1. Lebedeva N.A., Bobrovsky A.Ya., Pimmanskaya V.N., Tinyakov G.G., Kulikova V.I. Anatomy and histology of meat industry animals: textbook. M.: Easy industrial, 1985.- 368 p. 2. Diamond I.

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Cardiac muscular fabric

Cardiac muscular fabric Forms middle shell (myocardium) atrial and ventricles of the heart and is represented by two varieties of working and conductive.

The contracting apparatus of myocytes, as well as in skeletal muscle tissue, consists of myofibrils that occupy the peripheral part of the cell. Their diameter from 1 to 3 microns.

Myofibrils are similar to the myofibrils of skeletal muscle tissue. They are also constructed from anisotropic and isotropic disks, which also causes transverse allocations.

T-tubes in cardiac operating cardiomyocytes form Diaps, that is, connected with the tanks of the sarcoplasmic network only on the one hand. Working cardiomyocytes have a length of the width. The number of myofibrils in them is less than in muscle fibers.

The intensity and frequency of abbreviations of the heart muscle are regulated by nerve impulses.

Cardiac muscular fabric

DEVELOPMENT. The source of the development of cardiac mjekhoy tissue is the Mioepcardial plate, part of the visceral splashpotoma in the cervical embryo. Its cells turn into myoblasts that are actively divided by mitosis and differentiate. In the cytoplasm of myoblasts, myofilaments forming myofibrils are synthesized. Initially, myofibrils do not have allocated and a certain orientation in the cytoplasm. In the process of further differentiation, the longitudinal orientation and subtle myophilaments are attached to the forming seals of the sarchatimma (z-substance).

As a result, the ever-increasing orderliness of the myofibrils of myofibrils acquire transverse exhaustion. Cardiomytes are formed. In their cytoplasm, the content of organelles is growing: mitochondria, graspeed EPS, free ribosomes. In the process of differentiation, Cardio myocytes do not immediately lose the ability to divide and continue to multiply. In some cells there may be no cytotomy, which leads to the appearance of dual core cardiomyocytes. Developing cardiomyocytes have a strictly defined spatial orientation, setting up in the form of chains and forming intercellular contacts to each other - insert discs. As a result of the divergent differentiation, the cardiomyocytes turn into a cell of three types: 1) workers, or typical, contractile; 2) conductive, or atypical; 3) Secretory (endocrine). As a result of terminal differentiation, cardiomyocytes by the time or in the first months of postnatalo ontogenesis lose the ability to divide. In mature heart muscle tissue, Cambial cells are absent.

STRUCTURE. Cardiac muscular tissue is formed by cardi-oomiocyt cells. Cardiomyocytes are the only tissue element of heart muscle tissue. They are connected to each other using inserted disks and form functional muscle fibers, or a functional symplast that is not a symplast in a morphological concept. Functional fibers are branched and the anastomosy is the side surfaces, as a result of which a complex three-dimensional network is formed (Fig. 12.15).

Cardiomyocytes are elongated with a rectangular weakly precious shape. They consist of kernel and cytoplasm. Many cells (more than half of the adult individual) are duid and polyploid. The degree of polyptloidization is different and reflects the adaptive possibilities of myocardium. The kernels are large, bright, are in the center of cardiomyocytes.

The cytoplasm (sarcoplasma) of cardiomyocytes has pronounced OK-Syphilia. It contains a large amount of organelle and inclusions. The peripheral part of the sarcoplasma is occupied by the arranged longitudinally stressed myofibrils, constructed in the same way as in skeletal muscle tissue (Fig. 12.16). In contrast to the myofibrils of skeletal muscle tissue lying strictly isolated, in the cardiomyocytes, myofibrils are often merged with each other with the formation of a single structure and contain reduced proteins that are chemically different from the reduced proteins of myofibrils of skeletal muscles.

Sire and T-tubes are weaker than in skeletal muscle tissue, which is associated with the automation of the heart muscle and the smaller influence of the nervous system. In contrast to the skeletal muscle tissue, the SPR and the T-tube form not the triads, but the Diads (one tank of the SPR arrives to the T-tube). Typical terminal tanks are absent. SPR less intensively accumulates calcium. Outside, the cardiocytes are covered with a sarchatma consisting of a cardiompocyte plasma and basal membrane outside. The vasal membrane is closely associated with the intercellular substance, collagen and elastic fibers are woven. The basal membrane is absent in the places of inserts. Components of the cytoskeleton are associated with inserted disks. Through the integrins of the citolem, they are also associated with the intercellular substance. Insert wheels are a place of contacts of two cardiomyocytes, complexes of intercellular contacts. They provide both mechanical and chemical, functional communication of cardiomyocytes. In the light microscope, have a kind of dark transverse strips (Fig. 12.14 b). In the electron microscope, insert discs have a zigzag, step view or type of toothed line. They include horizontal and vertical sites and three zones (Fig. 12.1, 12.15 6).

1. Zones as desmembore and sticking strips. Are on vertical (transverse) areas of discs. Provide mechanical compound cardiomyocytes.

2. Nexus zones (slot contacts) - excitation transmission places from one cell to another, provide chemical communication of cardiomyocytes. Detected on the longitudinal sections of inserts. Miofibrill attachment zones. Low on transverse sections of inserts. Serve as in places attaching actin philants to Sarchatim Cardii-Ocita. This attachment occurs to the Z-strips detected on the inner surface of the sarchatum and similar Z-lines. In the field of inserts, there are large numbers of cadhelerins (adhesive molecules that carry out the calcium-dependent adhesion of cardio-myocytes with each other).

Types of cardiomyocytes. Cartoomyocytes have different properties in different parts of the heart. So, in the atrodi they can share mitosis, and in the ventricles are never divided. There are three types of cardiomyocytes that differ significantly from each other with a building and functions: workers, secretory, conductive.

1. Operating cardiomyocyte the structure described above.

2. Among the atrial myocytes there are secretory cardiomyocytes that produce a sodium system (NUF), which enhances the secretion of sodium by the kidneys. In addition, the NUF is relaxing the smooth Mi-Ocites of the arteries wall and suppresses the secretion of hormones causing hyper-tensulation (aldosteronea of \u200b\u200bvasopressin). Everything is leading to an increase in the diuresis and the lumen of the arteries, a decrease in the volume of circulating fluid and as a result - to a decrease in blood pressure. Secretor cardiomyocytes are localized mainly in the right atrium. It should be noted that all cardiomyocytes have the ability to synthesize in embryogenesis, but in the process of differentiation of ventricular cardiomyocytes, this ability is reversible, which can be recovered here during the overvoltage of the heart muscle.

3. Significantly different from working cardiomyocytes conductive (atypical) cardiomyocytes. Proceed with a conductive heart system (see "Cardiovascular system"). They are twice as much workers cardiomyocytes. There are few miofibrils in these cells, the volume of sarcoplasm is increased, in which a significant amount of glycogen is detected. Thanks to the content of the last cytoplasma of atypical cardiomyocytes, it does not perceive the color. The cells contain many lysosomes and there are no T-tube. The function of atypical cardiomyocytes is the generation of electrical impulses and transmit them to working cells. Despite the automatism, the work of cardiac muscle tissue is strictly regulated by the autonomic nervous system. The sympathetic nervous system participates and enhances, parasympathetic - replete and weakens heart abbreviations.

Regeneration of cardiac muscular fabric. Physiological regeneration. Realizes on the intracellular level and flows with high intensity and speed, since the heart muscle carries a huge load. Even more, it increases with severe physical work and in pathological conditions (hypertension, etc.). In this case, there is a constant wear of the components of the cytoplasm of cardiomyocytes and the substitution of their newly formed. With an increased load on the heart, hypertrophy occurs (increase in size) and hyperplasia (increase in quantity) organelle, including myofibrils with increasing in the last number of sarcomers. In young age, polyptloidization of cardiomyocytes and the emergence of dual cells are also noted. The working hypertrophy of myocardium is characterized by an adequate adaptive growth of its vascular bed. In pathology (for example, heart defects, also causing cardiomyocyte hypertrophy), it does not occur, and after a while due to nutritional disorders, the death of the cardiomyocytes occurs with the replacement of their scar tissue (cardiosclerosis).

Reparative regeneration. When wounds of the heart muscle, myocardial infarction and other situations. Since in the heart muscle tissue, Pet Cambial cells, then during damage to the myocardial ventricles, regenerator and adaptive processes go on an intracellular level in neighboring cardiomyocytes: they increase in size and take the function of dead cells. At the site of the dead cardiomyocytes, a connecting bracket is formed. Recently, it has been established that only the cardiomyocytes of the relatively small portion of the infarct zone and the nearby zone are captured at myocardial infarction. The more significant number of cardiomyocytes surrounding the infarct zone is dying by apotose, and this process is leading in the death of the cordial muscle cells. Therefore, the treatment of myocardial infarction primarily should be directed towards the suppression of the apoptosis of cardiomyocytes in the first day after the onset of heart attack.

In case of damage to the myocardium atrial in a small amount can be regenerated at the cellular level.

Stimulation of reparative regeneration of cardiac muscle tissue. 1) Preventing the apoptosis of cardiomyocytes by the purpose of drugs that improve the microcirculation of myocardium that reduces blood coagulation, its viscosity and improving the rheological properties of blood. The successful fight against post-infarction apoptosis of cardiomyocytes is an important condition for further successful myocardial regeneration; 2) the purpose of anabolic preparations (vitamin complex, RNA and DNA preparations, ATP, etc.); 3) Early use of dosage physical exertion, a complex of exercise of therapeutic physical education.

In recent years, in experimental conditions, the transplantation of skeletal muscle tissue was used to stimulate the regeneration of cardiac muscular tissue. It has been established that skeletal muscle fibers that are introduced into myocardium mocardia, which set close not only structural, but also functional communication with cardiomyocytes. Since the substitution of myocardial defect is not an inert connecting, but manifests the contractile activity with a skeletal muscle tissue more advantageous in functional and even in mechanical terms, then the further development of this method may be promising in the treatment of myocardial infarction in humans.

Muscular fabrics Combines the ability to reduce.

Particularities of the structure: a contractile apparatus, which occupies a significant part in the cytoplasm of the structural elements of muscle tissue and consisting of actin and alone filaments, which form special purpose organelles - miofibrils .

Classification of muscular fabrics

1. Morphofunctional classification:

1) Transverse, or exhausted muscular fabric: skeletal and heartfelt;

2) Unigenous muscular tissue: smooth.

2. Histogenetic classification (depending on sources of development):

1) Somatic type (from somitov's miotomites) - skeletal muscle tissue (transverse);

2) Children's type (from the mioepcardial plate of visceral sheet of splash) - heart muscle tissue (transverse);

3) Mesenchymal type (develops from mesenchym) - smooth muscular fabric;

4) From the skin ectoderma and proportal plate - Moepithelial cells of hotels (smooth myocytes);

5) Neural Origin (from a nervous tube) - Mioneral cells (smooth muscles, narrowing and expanding pupil).

Muscular fabric functions: Moving the body or its parts in space.

Skeletal muscular fabric

Occaped (cross-striped) muscular fabric It makes up to 40% of the mass of an adult, part of skeletal muscles, muscles of the language, larynx, etc. refer to arbitrary muscles, since their reductions are subject to the will of a person. It is these muscles that are involved in sports.

Histogenesis. Skeletal muscle tissue develops from the cells of the Miotomes of myoblasts. There are head, cervical, chest, lumbar, sacral Miotoma. They grow up in the dozal and ventral directions. The branches of the spinal nerves will grow early in them. Part of the myoblasts are differentiated in place (form an autochthonous musculature), and others from 3 weeks of intrauterine development migrate into the mesenchym and, merging with each other, form muscular tubes (Mitubs) With large centrally oriented nuclei. In the Miotubes there is differentiation of special organel miofibrils. Initially, they are located under the plasmolemma, and then fill most of the Miotuba. The kernels are shifted to the periphery. Cell centers and microtubules disappear, the pulps is significantly reduced. Such a multi-core structure is called symplast , and for muscle tissue - miosimplast . Some myoblasts are differentiated into miosatelitical acids, which are located on the surface of myosimplests and subsequently take part in the regeneration of muscle tissue.

Skeletal muscle tissue

Consider the structure of muscle tissue at several levels of living organization: at the organ level (muscle as an organ), on the tissue (directly muscle tissue), on the cell (the structure of muscular fiber), on the subcellular (structure of myofibrils) and at the molecular level (the structure of actin and mosinic threads).

On Carint:

1 - Muscle icy (organ level), 2 - transverse muscle cut (fabric level) - muscle fibers, between which RVST: 3 - endomisia, 4 - nervous fiber, 5 - blood vessel; 6 - cross-section of muscle fiber (cellular level): 7 - muscle fiber kernels - symplast, 8 - mitochondria between myofibrils, blue - sarcoplasmic reticulum; 9 - cross-section Miofibrillas (subcellular level): 10 - Thin Actin Threads, 11 - Thick Mosic Threads, 12 - Heads of Thick Mosic Threads.

1) Organ Level: Building muscles as an organ.

The skeletal muscle consists of beams of muscle fibers connected together by the system of connective tissue components. Endomisium- Strikes RVST between muscle fibers where blood vessels pass, nerve endings . Perimisia - surrounds 10-100 bunches of muscle fibers. Epimizius - The outer sheath of the muscles is represented by a dense fibrous cloth.

2) fabric level: structure muscle tissue.

The structural and functional unit of skeletal transverse (acheutable) muscle tissue is muscular fiber - cylindrical form formation with a diameter of 50 microns and a length of 1 to 10-20 cm. Muscular fiber consists of 1) miosimplest (look at it above, the structure is lower), 2) small cambial cells - miosatelitocyteMoving to the surface of the Miosimplast and are located in the recesses of its plasmolemma, 3) of the basal membrane, which is covered by plasmolem. The complex of plasmolem and the basal membrane is called sarchatimma. For muscle fiber, the transverse allocation is characterized, the kernel is shifted to the periphery. Between muscle fibers - Strusting RVST (endomisia).

3) Cellular level: structure muscular fiber (miosimplast).

The term "muscular fiber" implies Miosimplast, since myiosimplast provides a reduction function, myosatellocytes participate only in regeneration.

Miosimplast, like a cell, consists of 3 components: nuclei (or rather than nuclei), cytoplasm (sarcoplasma) and plasmolemma (which is covered with a basal membrane and is called Sarcolmma). Almost the entire volume of the cytoplasm is filled with Miofibrils - special purpose orgellary, general purpose organelles: GREPS, AEPS, Mitochondria, Golgi complex, lysosomes, and the kernel are shifted to the periphery of the fiber.

In muscle fiber (miosimplast) differ functional devices: membrane, fibrillar (contractile) and trophic.

Trophic apparatusincludes kernels, sarcoplasm and cytoplasmic organelles: mitochondria (energy synthesis), GREPS and Golgi complex (protein synthesis - structural components of myofibrils), lysosomes (phagocytosis of worn-out structural fiber components).

Membrane apparatus: Each muscular fiber is covered with a sarchatma, where the outer basal membrane is distinguished (under the basal membrane), which forms pensions ( T.-Pube). To each T.-Pube is adjacent two tanks triad: Two L.- Hubles (Tsters of AEPS) and one T.-Pube (plasmolm piercing). In the tanks of the AEPS concentrate SA 2+ required while reducing. Miosatellitocytes arrive outside the plasmolemma. In case of damage to the basal membrane, the mitotic cycle of myosatellitocytes is launched.

Fibrillar apparatusThe long part of the cytoplasm of the allocated fibers occupy special purpose organelles - miofibrillas, are oriented longitudinally, providing contractile function of tissue.

4) Sub-cell level: Building miofibrils.

In the study of muscle fibers and myofibrils under a light microscope, there is an alternation of dark and light sections in them. Dark discs are distinguished by double bempraine and are called anisotropic disks, or BUT- disks. Light discs do not possess double bempraine and are called isotropic, or I.-Disc.

In the middle of the disk BUT There is a brighter area - N.-zone, where only thick threads of myozin protein are contained. In the middle N.-sons (means BUT-dy) stands out darker M.-Linia consisting of Miomesin (needed to assemble thick threads and fixing them with reduction). In the middle of the disk I. Located dense line Z.which is built of protein fibrillar molecules. Z.-Ronia is connected to neighboring myofibrils using desphan protein, and therefore all these lines and drives of neighboring myofibrill coincide and a picture of the transverse perverse of the muscular fiber is created.

The structural unit of myofibrilla is Sarcomer (S.) — this is a bunch of myofilaments prisoner between two Z.-lines. Myofibrill consists of a variety of sarcomers. The formula describing the structure of the Sarcomer:

S. = Z. 1 + 1/2 I. 1 + BUT + 1/2 I. 2 + Z. 2

5) Molecular level: Building aktinov and mosinova Filaments .

Under the electron microscope, miofibrillas are aggregates from thick, or mosinova, and thin, or aktinov, filaments. Between thick filaments are thin filaments (diameter 7-8 nm).

Thick filaments, or alone threads,(diameter 14 nm, length 1500 nm, the distance between them is 20-30 nm) consist of molecules of the protein of myosin, which is the most important contractile protein of the muscle, 300-400 molecules of myosis in each thread. Miosis molecule is a hexamer consisting of two heavy and four light chains. Heavy chains are two spiral twisted polypeptide threads. They carry spherical heads at their ends. There is a hinge section between the head and heavy chain, with which the head can change its configuration. In the head area - light chains (two each). Misepes molecules are laid in thick threads in such a way that their heads are turned outward, speaking over the surface of thick threads, and heavy chains form a thick thread rod.

Myosin has ATP-azna activity: released energy is used for muscle contraction.

Thin filaments, or actin threads, (Diameter 7-8 nm), formed by three proteins: actin, troponin and tropomosin. The main most protein is Aktin, which forms a spiral. Tropomyozin molecules are located in the groove of this helix, troponin molecules are located along the spiral.

Thick threads occupy the central part of Sarcomer - BUT-disk, thin occupy I.- disks and partially included between thick myophilaments. N.- It consists of thick threads.

At rest interaction of thin and thick threads (myofilaments)it is impossible, because Myozin-binding plots of actin are blocked by troponin and tropomosin. With a high concentration of calcium ions, conformational changes in tropomyosine lead to unlocking the myozin-binding sections of actin molecules.

Muscular fiber motor innervation. Each muscular fiber has its own innervation apparatus (motor plaque) and is surrounded by a network of hemokapillars located in the adjacent RVST. This complex is called mion. A group of muscle fibers that are innervated by one motoryone called nervous muscular unit. Muscular fibers in this case can be placed nearby (one nervous end can control from one to dozen muscle fibers).

When the nerve impulses arrives in the axon of motor neurons occurs reduction of muscle fiber.

Reduced muscle

When reducing muscle fibers are shortened, but the length of the actin and mosic filaments in the myofibrils does not change, and their movement occurs relative to each other: myosine threads are moving into space between Aktinov A, Aktinov - Between myosinov. As a result, the width is reduced I.-disc H.-poligas and decreases the length of the sarcomer; width BUT-Disc does not change.

Sarcomer formula with full reduction: S. = Z. 1 + BUT+ Z. 2

Molecular Muscular Reduction Mechanism

1. Passage of a nerve impulse through neuro-muscular synaps and depolarization of muscle fiber plasmolem;

2. The depolarization wave passes by T.- pipes (plasmolem piercing) to L.-Tubeons (sarcoplasmic reticulum tanks);

3. Opening of calcium channels in sarcoplasmic reticulum and ion yields SA 2+ in sarcoplasma;

4. Calcium diffuses to thin threads of the sarcomer, binds to troponin C, leading to conformational changes in tropomyosis and freeing active centers for the binding of myosin and actin;

5. The interaction of myosine heads with active centers on the actin molecule with the formation of actino-mosic "bridges";

6. The myosine heads "walk" on the actin, forming new connections of actin and myosin during the movement, while actin threads are tightened into the space between myosine threads to M.-lini, bringing away two Z.-lini;

7. Relaxation: SA 2+ -atf-az sarpoplasmic reticulum pumps SA 2+ from sarcoplasma in tanks. In sarcoplasm concentration SA 2+ becomes low. Troponin's bonds are broken FROM With calcium, tropomyosis closes the myosin-binding plots of thin threads and prevents them from interacting with myosin.

Each movement of the MIOSIN head (accession to the actine and disconnection) is accompanied by the cost of ATP.

Sensitive innervation (neuromuscular spindle). Intrafusal muscle fibers together with sensitive nerve endings form neuromuscular spindles, which are a skeletal muscle receptors. Outside formed a capsule spindle. When reducing cross-striped (running) muscle fibers, the tension of the connecting and woven capsule is changed and the tone of intraphus (arranged under the capsule) of muscle fibers changes accordingly. A nervous impulse is formed. With excessive stretching, the muscles arises a feeling of pain.

Classification and types of muscle fibers

1. By the nature of the reduction: phase and tonicmuscular fibers. Phase are able to carry out rapid abbreviations, but cannot hold the achieved shortening level. Tonic muscle fibers (slow) provide maintaining static voltage or tone, which plays a role in maintaining a certain position of the body in space.

2. According to biochemical features and color Highlight red and white muscular fibers. The color of the muscles is due to the degree of vascularization and the content of myoglobin. The characteristic feature of the red muscular fibers is the presence of numerous mitochondria, the chains of which are located between the myofibrils. In white muscle fibers, mitochondria are smaller and they are uniformly in the sarcoplasm of muscle fiber.

3. By type of oxidative exchange : oxidative, glycolithic and intermediate. The identification of muscle fibers is based on the identification of the activity of the enzyme succinate dehydrogenase (SDH), which is a marker for mitochondria and the Krebs cycle. The activity of this enzyme indicates the tension of energy metabolism. Muscular fibers are isolated BUT-Type (glycolithic) with low SDG activity, FROM-Type (oxidative) with high activity ADH. Muscular fibers IN-Type occupy an intermediate position. Muscular fiber transition from BUT-Type B. FROM-Type lakes changes from anaerobic glycolysis to metabolism, depending on oxygen.

Sprinter (athletes, when fast short-range reduction, bodybuilders need) workout and nutrition is aimed at the development of glycolytic, fast, white muscular volccasses: there are many glycogen reserves and energy produced mainly by analombic way (white meat in chicken). Styers (athletes - Marathonians, in those sports where endurance is needed) oxidative, slow, red fibers in muscles are dominated - there are many mitochondria in them for aerobic glycolysis, blood vessels (needed oxygen).

4. In the running muscles, two types of muscle fibers distinguish: extrafusalwho prevail and cause actually the contractile function of the muscles and intrafusalincluded in propriceceptors - neuromuscular spindles.

The factors defining the structure and function of the skeletal muscle are the effect of nervous tissue, hormonal effect, muscle location, level of vascularization and motor activity.

Cardiac muscular fabric

Heart muscular fabrics in the muscular shell of the heart (myocardium) and in the mouths of the large vessels associated with it. It has a cellular type of structure and the main functional property is the ability to spontaneous rhythmic abbreviations (involuntary reductions).

It develops from a mioepcardial plate (visceral leaflet of mesoderm in the cervical leaflet), the cells of which are multiplied by mitosis, and then differentiate. The cells appear in the cells, which further form myofibrils.

Structure. Structural unit of cardiac muscular fabric - cell cardiomiocyte.Between the cells there are interlayers of the RVST with blood vessels and nerves.

Types of cardiomyocyte : 1) typical (workers, contractile), 2) atypical(conductive), 3) secretory.

Typical cardiomyocytes

Typical (workers, contractile) cardiomyocytes - Cylindrical cells, up to 100-150 μm long and 10-20 μm diameters. Cardiomyocytes form the bulk of myocardium, connected to each other in the chain bases of cylinders. These zones are called inserted discsin which the desmotomomal contacts and nexus (slut-like contacts) are distinguished. Desmosomoms provide mechanical clutch, which prevents the discrepancy of cardiomyocytes. Slim contacts contribute to the transfer of reduction from one cardiomyocyte to another.

Each cardiomyocyte contain one or two nuclei, sarcoplasm and plasmolem, surrounded by the basal membrane. There are functional devices, the same as in the muscular fiber: membrane, fibrillar (contractile), trophic,as well as Energy.

Trophic apparatus includes the kernel, sarcoplasma and cytoplasmic organelles: GREPS and the Golges complex (protein synthesis - structural components of myofibrils), lysosomes (phagocytosis of the structural components of the cell). Cardiomyocytes, like the olokna skeletal muscle tissue, are characterized by the presence of iron-containing oxygen-binding pigment of myoglobin, which gives them red and similar in structure and function with hemoglobin erythrocytes in their sarcoplasma.

Energy apparatus Presented by mitochondria and inclusions, whose splitting ensures energy. Mitochondria is numerous, lie between fibrils, in the poles of the nucleus and under the Sarcollam. The energy required by cardiomyocytes is obtained by splitting: 1) the main energy substrate of these cells - fatty acidswho are deposited in the form of triglycerides in lipid drops; 2) glycogen in granules located between fibrils.

Membrane apparatus : Each cell is covered with a shell consisting of a plasmolem complex and basal membrane. The shell forms fusion ( T.-Pube). To each T.-Tube is adjacent one tank (unlike muscle fiber - 2 tanks) sarpoplasmatic reticuluma (modified AEPS), forming dida: one L.-buchka (tank AEPS) and one T.-Pube (plasmolm piercing). In the tanks of the AEPS ions SA 2+ accumulate not as actively as in muscle fibers.

Fibrillar (contractile) apparatus Cardiomyocyt's large part of the Cardiomiocyt cytoplasma is occupied by special purpose organelles - miofibrillas, are oriented longitudinally and located along the periphery cells. The coding apparatus of workers cardiomyocytes with skeletal muscle fibers. When relaxing, calcium ions are highlighted in a sarcoplasma at a low rate, which ensures automatism and frequent cuts of cardiomyocytes. T.-brubs wide and form Diaps (one T.-Pube and one network tank) that converge in the area Z.-Line.

Cardiomyocytes, binding to inserted discs, form contractile complexes, which contribute to the synchronization of the reduction, side anastomoses are formed between cardiomyocytes of adjacent contractile complexes.

Function of typical cardiomyocyte: Ensuring the strength of reduction of the heart muscle.

Conductive (atypical) cardiomyocytes have the ability to generate and rapid electrical impulses. They form nodes and bundles of the conductive heart system and are separated into several subtypes: PaceMekers (in the synoatrile node), transitional (in an atrio-ventricular node) and a beam cells of His and fibers Purkinje. Cardiomyocytes are characterized by the weak development of the contractile apparatus, light cytoplasm and large nuclei. There are no T-tubes and transverse aperture in cells, since myofibrils are located disordered.

Function atypical cardiomyocyte - generation of pulses and transmission to working cardiomyocytes, providing an automatism of myocardial reduction.

Secretor cardiomyocytes

Secretory cardiomyocyte in atriums, mainly in the right; Characterized by the processful shape and weak development of the contractile apparatus. In the cytoplism, near the core poles - secretory granules containing sitting factor, or atropeptine (hormone, regulating blood pressure). The hormone causes the loss of sodium and water with the urine, the extension of the vessels, a decrease in pressure, the oppression of the secretion of aldosterone, cortisol, vasopressin.

Function of secretory cardiomyocyte: endocrine.

Cardiomyocyte regeneration. For cardiomyocytes, only intracellular regeneration is characteristic. Cardiomyocytes are not capable of dividing, they have no cambial cells.

Smooth muscular fabric

Smooth muscular fabric forms the walls of the inner hollow organs, vessels; It is characterized by the lack of a allocated, involuntary abbreviations. Innervation is carried out by the vegetative nervous system.

Structural and functional unit of an inexhariced smooth muscle tissue - smooth muscular cell (MMC), or smooth myocyte. Cells have a spit-shaped form with a length of 20-1000 μm and a thickness of 2 to 20 microns. In the cell of the cells have an elongated process.

Smooth myocyt

The smooth myocyte consists of a nuclear-shaped kernel located in the center of the nucleus, cytoplasm with organelles and sarchatimms (plasmolem complex and basal membrane). In the cytoplasm at the Poles there is a Golgi complex, many mitochondria, ribosomes, and a sarcoplasmic reticulum is developed. Miofilaments are located space or along the longitudinal axis. In MMC, Aktinovy \u200b\u200band myosin filaments do not form myofibrils. Actin threads are larger and they are attached to dense tales, which are formed by special crosslinking proteins. Next to the actin threads are myosin monomers (micromyosis). Possessing different lengths, they are much shorter than thin threads.

Reducing smooth muscle cells It is carried out in the interaction of actin filaments and myosin. The signal running through the nervous fibers causes the mediator allocation, which changes the state of the plasmolemma. It forms flask-shaped phenomenon (Cavaoma), where calcium ions are concentrated. The reduction of the MMC is induced by the influx of calcium ions in cytooplasm: Cavools are packed and together with calcium ions fall into the cell. This leads to the polymerization of myosin and interacting it with actin. Actin threads and dense calves come closer, the force is transmitted to Sarchatum and the MMC is shortened. Myosin in smooth myocytes is able to interact with actin only after phosphorylation of its light chains with a special enzyme - a kinase of light chains. After stopping the calcium ion signals, Caveolas leave; Myozic depolarizes, loses affinity for actin. As a result, complexes of myofilaments are disintegrated; Reduction stops.

Special types of muscle cells

Moepithelial cells Exterma derivatives are derived, do not have allocated. The secretory departments and output duct glands (salivary, dairy, tear) are surrounded. With iron cells, they are associated with desmosomes. Reducing, contribute to the allocation of the secret. In the terminal (secretory) departments, the shape of the cells of the outflow, star. The core in the center, in the cytoplasm, mainly in the process of localized myophilaments that form a contractile device. In these cells there are cytokheratin intermediate filaments, which emphasizes their similarity with epithelocytes.

Mioneral cells they develop from the cells of the outer layer of the eye gland and form the muscle, the narrowing pupil and the muscle expanding the pupil. According to the structure, the first muscle is similar to Menchima Museum. The muscle that expanding the pupil is formed by the cells of the cells are located radially, and the poison-containing part of the cell is between the pigment epithelium and the stroma iris.

Myofibroblasts refer to loose connective tissue and are modified fibroblasts. They show the properties of fibroblasts (the intercellular substance synthesize) and smooth myocytes (have pronounced contracting properties). As a variant of these cells can be considered mioid cells As part of the walls of the convoluted seed tuber of the egg and the ovar ovarian follicle layer. When healing wounds, part of fibroblasts synthesize smooth muscle actines and mosins. Myofibroblasts ensure that the edges of the wound are tightened.

Endocrine smooth myocytes - These are modified MMC, representing the main component of the yukstaglomelar kidney apparatus. They are in the wall arteriole of the renal body, have a well-developed synthetic apparatus and reduced contractile. The enzyme renin produced in the granules and the exocytosis mechanism falling into the blood.

Regeneration of smooth muscle tissue.Smooth myocytes are characterized by intracellular regeneration. With an increase in the functional load, the hyperrophy of myocytes and in some organs hyperplasia (cellular regeneration) occurs. So, during pregnancy, smooth muscle cells of the uterus can increase 300 times.