Epithelial tissue: structural features, functions and types. Difference Between Epithelial Tissue and Connective Epithelial Tissue Formation

Date: 01.07.2020

The human body has a complex structure. It consists of various structures characterized by different levels of biological organization of living matter: cells with intercellular substance, tissues and organs. All structures of the body are interconnected, while cells with intercellular substance form tissues, organs are built from tissues, organs are combined into organ systems.

In the body, tissues are closely related morphologically and functionally. The morphological relationship is due to the fact that different tissues are part of the same organs. The functional connection is manifested in the fact that the activity of different tissues that make up the organs is coordinated. This consistency is due to the regulatory influence of the nervous and endocrine systems on all organs and tissues.

Distinguish between general and specialized fabrics. Tissues of general importance include:

epithelial or border tissues, their functions - protective and external exchange;

connective tissues or tissues of the internal environment, their functions are internal exchange, protective and supporting.

Various tissues, connecting with each other, form organs. It usually consists of several types of tissues, with one of them performing the main function of the organ (for example, muscle tissue in skeletal muscle), while others perform auxiliary functions (for example, connective tissue in muscle). The main tissue of the organ, which ensures its function, is called its parenchyma, and the connective tissue that covers it from the outside and penetrates it in different directions is called the stroma. In the stroma of the organ, there are vessels and nerves that carry out the blood supply and innervation of the organ.

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State budgetary educational institution
secondary vocational education of the city of Moscow
"Medical School No. 8
Moscow Department of Health "
(GBOU SPO "MU No. 8 DZM")

Methodical development of a practical lesson

(for students)

Academic discipline: OP.02 "Human Anatomy and Physiology"Theme: "Epithelial and connective tissue"

Specialty: 34.02.01 NursingCourse: 2

Teacher: Lebedeva T.N.

2015 year

Practical lesson

Topic: “Epithelial and

connective tissue “

Lesson objectives:

Students should know:

Fundamentals of the structure and function of various types of epithelial and connective tissue.

Students should be able to:

Distinguish on micropreparations, posters: varieties of monolayer, stratified epithelium, glands, fibrous connective tissue, connective tissue with special properties, skeletal connective tissue.

Chronocard of the occupation.

Busy plan:

Organizational part - 2 min.

Control of the initial level of knowledge (survey), demonstration of cells, varieties of epithelial and connective tissues, an overview of their functions. Assignment for independent work and

self-control - 15 min.

Independent work and self-control - 55 min.

3. Final control - 15 minutes.

Summing up the lesson and homework - 3 min.

Method of carrying out.

Practical lesson with fragments of your own - search work.

Equipment for the lesson.

Posters, micropreparations with various types of epithelial tissue, glands, connective tissue, microscopes, "Atlas of normal human anatomy" V.Ya. Lipchenko et al., Textbooks by E.A. Vorobieva et al. "Anatomy and physiology", L.F. Gavrilova and others. "Anatomy".

Technological map of the theoretical lesson

SECTION 2. Selected issues of cytology and histology
Topic 2.2. Basics of Histology. Classification of fabrics. Epithelial, connective tissue.
Class No.	3. Epithelial, connective tissue.
Occupation type	lesson assimilation of new knowledge, generalization and systematization of knowledge
The form holding	lecture
Lesson objectives To know:	definition of "Fabrics" classification of fabrics localization, structural features, varieties and functions of epithelial tissues (integumentary and glandular epithelium and their varieties) connective tissue classification localization, structural features, varieties and functions of connective tissues (fibrous, with special properties, skeletal tissues, their varieties)
Equipment for the lesson	board, chalk ■ tables "Stratified epithelium", "Unilamellar epithelium", "Glandular epithelium", "Scheme of the structure of glands" of the table "Lamellar bone tissue. The structure of the long bone "," Cartilage tissue "," Dense fibrous connective tissue "," Loose fibrous connective tissue "," Adipose tissue "
Training literature	Shvyrev A.A. Human anatomy and physiology with the basics of general pathology. Textbook for medical schools and colleges. Rostov-on-Don. "Phoenix", 2014, - 412 p. Samusev R.P., Lipchenko V.Ya. Atlas of Human Anatomy [Text]. M .: OOO "Izd. House "Onyx 21st Century": LLC "Peace and Education", 2007.

Course of the lesson:

	stage lessons	time (min.)	methods	teacher activity	student activities
	The organization onny moment			Fills in the journal, informs students about the topic, goals and lesson plan.	Write down the topic and goals of the lesson in a notebook.
	Motivation educational activities		Explanatory illustrative	Motivates students to learn new material	Listen, answer the teacher's questions
	Presentation new material		Explanatory illustrative reproductive partially search.	Explains new material, accompanies the explanation with a demonstration of tables, tablets, anatomical dummies and models, as well as pictures and diagrams on the board.	They write down new material in a notebook, draw diagrams; consider visual aids; analyze situations suggested by the teacher as an example.
	Reflection		Problem.	Emphasizes students' attention on the most important points of the lesson. Answers the questions. Offers to generalize the material studied, to assess the degree of achievement of the objectives of the lesson.	Ask questions, generalize what was learned in the lesson. Assess the individual degree of achievement of goals.
	Outcome lessons			Evaluates the work of the group in class, gives homework.	Write down homework.
Total class time90 minutes

ACTIVITY MOTIVATION

Distinguish between general and specialized fabrics. Tissues of general importance include:

epithelial or border tissues, their functions - protective and external exchange;

connective tissues or tissues of the internal environment, their functions - internal exchange, protective and supporting.

Various fabrics, connecting with each other, formorgans. It usually consists of several types of tissues, with one of them performing the main function of the organ (for example, muscle tissue in skeletal muscle), while others perform auxiliary functions (for example, connective tissue in muscle). The main tissue of the organ, which ensures its function, is called its parenchyma, and the connective tissue that covers it from the outside and penetrates it in different directions is called the stroma. In the stroma of the organ, there are vessels and nerves that carry out the blood supply and innervation of the organ.

Baseline control questions

The cell and its basic properties.
The main parts of the cell.
Cell organelles and their functions.
Fabric, main types of fabrics.
Position and function of epithelial tissue.
Distinctive features of epithelial tissue.
Types of epithelial tissue.
What is Mesothelium?
Varieties of monolayer epithelium.
Exo- and endocrine glands.
Features of the structure of connective tissue.
Connective tissue functions.
Types of connective tissue.
Varieties of fibrous connective tissue.
The main types of cells of loose connective tissue.
A variety of connective tissue with special properties.
Varieties of skeletal connective tissue.
The structure and types of cartilage tissue.
Bone tissue and its varieties.

Task number 2

Using the literature recommended in item 1 of task No. 1, study the structure of connective tissue and its difference from epithelial tissue. In this case, pay attention to the following morphological features of the connective tissue:

it has a wide variety in structure;
it is less rich in cells than epithelial tissue;
its cells are always separated by significant layers of intercellular substance, including the main amorphous substance and special fibers (collagen, elastic, reticular);
it, in contrast to epithelial tissue, is a tissue of the internal environment and almost never contacts the external environment, internal cavities and participates in the construction of many internal organs, combining various types of tissues with each other;
the physicochemical features of the intercellular substance and its structure largely determine the functional significance of the connective tissue varieties.

In fig. see the connective tissue classification scheme.

Consider slides with loose, dense unformed and formed fibrous connective tissue, reticular, adipose, cartilage and bone tissue. On a micropreparation with a loose fibrous connective tissue, find (against the background of the main amorphous substance, collagen and elastic fibers) the main cells of this tissue type and familiarize yourself with their functions:

fibroblasts are involved in the production of the main amorphous substance and collagen fibers; fibroblasts that have completed a developmental cycle are called fibrocytes;
poorly differentiated cells are able to transform into other cells (adventitia cells, reticular cells, etc.);
macrophages are capable of phagocytosis;
tissue basophils (mast cells) produce heparin, which prevents blood clotting;
plasma cells provide humoral immunity (synthesize antibodies - gamma globulins);
lipocytes (adipocytes) - fat cells accumulate reserve

fat;

pigment cells (melanocytes) - pigment cells contain the pigment melanin.

Loose fibrous connective tissue is found in all organs, as it accompanies the blood and lymph vessels and forms the stroma of many organs.

Considering micropreparations with varieties of dense fibrous connective tissue, pay attention to the fact that in an unformed dense tissue against a background of a small number of cells, collagen and elastic fibers are densely arranged, intertwined and go in different directions, and in a formalized one - they go only in one direction. The first type of dense fibrous connective tissue forms a reticular layer of the skin, and the second - the tendons of muscles, ligaments, fascia, membranes, etc.

Studying reticular, adipose, gelatinous, pigment tissues, note that they are all characterized by a predominance of homogeneous cells, which are usually associated with the very name of connective tissue varieties with special properties.

Next, consider the types of skeletal connective tissue: cartilage and bone. Cartilage tissue consists of cartilage cells (chondrocytes), located in groups of 2-3 cells, the main substance and fibers. Depending on the structural features of the intercellular substance, select 3 types of cartilage: hyaline, elastic and fibrous. Geolin cartilage forms almost all articular cartilage, rib cartilage, airways, epiphyseal cartilage. Elastic cartilage forms the cartilage of the auricle, part of the auditory tube, external auditory canal, epiglottis, etc. Fibrous cartilage is part of the intervertebral discs, pubic symphysis, intra-articular discs and menisci, sternoclavicular and temporomandibular joints. Bone tissue consists of bone cells (osteocytes) embedded in a calcified intercellular substance containing ossein (collogenic) fibers and inorganic salts. It forms all the bones of the skeleton, being at the same time a depot of minerals, mainly calcium and phosphorus. Depending on the location of the bundles of ossein fibers, two types of bone tissue are distinguished: coarse-fibrous and lamellar. In the first tissue, bundles of ossein fibers are arranged in different directions. This tissue is inherent in embryos and young organisms. The second tissue consists of bone plates, in which the ossein fibers are arranged in parallel bundles inside the plates or between them. It can be compact and spongy. The compact bone tissue consists mainly of the middle part of the long tubular bones, and cancellous bone tissue forms their ends, as well as short bones. Flat bones contain both the one and the other bone tissue. To sing the body and the end

Task number 3

Fill in LDS "epithelial tissue"
Fill in LDS “connective tissue”
Solve tasks:

Problem 1

how can one explain the high strength of stratified squamous epithelium, which remains intact (intact) even after rather strong mechanical stress?

Problem 2

two classmates Kolya and Misha, 11 years old, while skiing down a steep hill on a sled in winter, turned over and got injured: Kolya - an extensive superficial abrasion in the area of \u200b\u200bthe right knee joint and lower leg, and Misha - a deep bruised and lacerated wound measuring 2 x 0.5 cm in the area of \u200b\u200bthe elevation of the thumb of the left hand. How, in your opinion, will the regeneration and healing of soft tissues in both schoolchildren take place?

Problem 3

name the main cells of loose fibrous connective tissue, which are actively involved in the body's defense, and the specific functions of these cells.

Task 4

what is the macrophage system of the body and which cells belong to it?

long tubular bone, visually familiarize yourself with the structure of these two types of bone tissue.

Sketch into albums from fig. 4-8 on pages 22-24, 26 "Anatomy"

LF Gavrilova and others. Some types of connective tissue: loose, dense unformed and formed, reticular, fatty, cartilaginous and bone. You can finish sketching in fabric albums at home.

Are common

function

General
character -
history

Classi -
fication

Genetic and
morpho-functional
cash types
epithelium

Varied
these epithelia

Morpho-funk -
national
character
cells

Character
located -
nuclei

Private

function

Test on the topic:

"Epithelial tissue

indicate which of the following functions are common functions of epithelial tissues:

a) external exchange,

b) internal exchange,

c) protective function,

d) trophic function.

Indicate which of the following mechanisms constitute the function of external exchange:

a) the accumulation of substances in the body,

b) the intake of substances into the body,

c) synthesis of a substance,

d) the release of substances from the body.

Indicate which of the following characteristics are inherent in epithelial tissues:

a) the presence of intercellular substance,

b) cell layer,

c) border area / sage,

d) the presence of blood vessels,

e) lack of blood vessels,

f) the presence of a basement membrane,

g) lack of basement membrane,

h) polar differentiation,

i) apolarity of cells,

j) low regenerative capacity,

l) high regenerative capacity.

Indicate which of the listed epithelia belong to the group of unilamellar epithelia:

a) flat,

b) cubic,

c) cylindrical,

d) transitional,

e) keratinizing.

Indicate which of the following functions are inherent in stratified epitheliums:

a) motor,

b) secretory,

c) protective.

Indicate which of the following methods of secretion is characterized by exocrine (1), endocrine (2), and mixed (3) glands:

a) secretion of secretion into the internal environment of the body,

b) the allocation of a secret to the external environment.

What are the general functions of epithelial tissues?
Name the types of unilamellar epithelium according to their shape.
What are the varieties of stratified epithelium?
What tissue always underlies epithelial tissue?
List organelles of special significance found in epithelial tissue.

Test on the topic:

" Connective tissue "

Reticular tissue

Indicate which of the listed organs includes the reticular tissue:

a) muscles,

b) tendons,

c) leather,

d) hematopoietic organs.

Indicate which of the following components are part of the intercellular substance of the reticular tissue:

a) basic substance,

b) basement membrane,

c) lymph,

d) collagen fibers,

e) reticular fibers.

Indicate which of the following functions is performed by the intercellular substance of the reticular tissue:

a) support,

b) protective,

c) contractile.

Indicate which of the following functions is performed by the reticular tissue:

a) support,

b) contractile,

c) trophic,

d) secretory,

e) protective.

Loose fibrous unformed connective tissue.

Indicate which of the following components are part of the loose fibrous unformed connective tissue:

a) basement membrane,

b) cellular elements,

c) meucellular substance.

Indicate which of the following functions are performed by loose fibrous unformed connective tissue:

a) trophic,

b) participation in external exchange,

c) support,

d) excretory,

e) protective.

Indicate which of the listed types of fibers are part of the loose fibrous unformed connective tissue:

a) chondrinic,

b) reticular,

c) ossein,

d) elastic,

e) collagen.

Indicate which of the following patterns of fiber location are characteristic of loose fibrous loose connective tissue:

a) ordered,

b) disordered.

Indicate which of the listed cellular elements are part of the loose fibrous unformed connective tissue:

a) fibroblasts,

b) fibrocytes,

c) leukocytes,

d) chondroblasts,

e) neurocytes,

f) histiocytes-macrophages,

g) epithelial cells,

h) plasma,

i) obese,

j) reticular,

l) e! sir,

m) pigmented,

m) poorly differentiated.

Indicate which of the following functions are performed by the fibroblast:

a) phagocytosis,

b) the production of antibodies,

c) the formation of the basic substance,

d) the formation of fibers.

Indicate which of the following functions is performed by histiocyte-macrophage:

a) support,

b) the formation of the basic substance of loose fibrous unformed connective tissue,

c) protective.

Indicate which of the following functions is performed by a plasma cell:

a) the formation of the basic substance of loose fibrous unformed connective tissue,

b) support,

c) the production of antibodies,

d) the production of proteolytic enzymes.

Dense connective tissue.

Indicate which of the following tissues are included in the group of dense connective tissues:

a) coarse fiber,

b) lamellar,

c) unformed,

d) formalized.

Specify the localization in the body of dense unformed (1) and densely formed (2) connective tissues:

a) tendons,

b) mesh layer koe / si,

c) ligaments.

Indicate which of the following components are part of the intercellular substance of dense connective tissues:

a) bundles of reticular fibers,

b) lymph, c) bundles of collagen fibers,

d) basic substance.

Indicate which of the following functions is performed by dense connective tissues:

a) trophic,

b) support,

c) protective.

Cartilage tissue

Indicate which of the following components are part of the cartilage tissue:

a) the periosteum,

b) perichondrium,

c) cellular elements,

d) terminal glandular sections,

e) basic substance,

f) chondrin fibers,

g) ossein fibers.

Indicate which of the following functions are performed by cartilage tissue:

a) regenerative,

b) support,

c) trophic,

d) participation in carbohydrate metabolism,

e) protective.

Indicate which of the following cells are part of the cartilage tissue:

a) fibroblast,

b) chondroblast,

c) fibrocyte,

d) chondrocyte.

Please indicate. In which of the following structures elastic cartilage is localized:

a) ribs,

b) airways,

c) auricle,

d) epiglottis,

e) the skeleton of the embryo,

f) laryngeal cartilage.

Indicate which of the following characteristics are inherent in the intercellular substance of elatic cartilage:

a) many elastic fibers,

b) rich in water,

c) few collagen fibers,

d) the presence of areas of calcification,

e) lack of areas of calcification.

Specify in which of the listed structures the collagen-fibrous cartilage is localized:

a) meyupozv it on-line disks,

b) auricle,

c) the symphysis of the pubic bones,

d) ribs,

e) airways,

f) sternoclavicular joint,

g) soft jaw fussing,

h) cartilage of the larynx,

i) places of transition of fibrous tissue into hyaline cartilage.

Bone

Indicate which of the following functions are characteristic of bone tissue:

a) participation in carbohydrate metabolism,

b) support,

c) secretory,

d) participation in mineral metabolism.

Indicate which of the following cells are part of the bone tissue:

a) fibroblast,

b) osteoblast,

c) mast cell,

d) osteocyte,

e) osteoclast,

f) chondrocyte,

e / s) plasma cell.

Indicate which of the following components are part of the intercellular substance of cartilage (1) and bone (2) tissues:

a) ossein fibers,

b) chondrin fibers,

c) osseomucoid,

d) inorganic salts,

e) chondromucoid,

f) glycogen.

Indicate what types of bone plates are contained in lamellar bone tissue:

a) osteon plates,

b) closure,

c) delimiting,

d) intercalary,

e) internal general,

f) basal,

e / s) outdoor general.

Specify the nature of the location of ossein fibers in coarse fibrous (1) and lamellar (2) bone tissue:

a) orderly,

b) randomly.

Indicate, with the help of which of the listed structures the bone grows in length (1) and in width (2):

a) epiphyseal growth plate,

b) periosteum.

Standards of answers to the test:
"Epithelial tissue"

a, in
b, d
b, c, d, f, h, l
a B C
1-6, 2-a, 3 - a, b
a-external exchange, b-protective (barrier)
a-flat, b-cubic, c-cylindrical
a-keratinizing, b-non-keratinizing, c-transient
a-connective tissue
a-tonofibrils, b-cilia, c-microvilli

Standards of answers to the test:
“ Connective tissue ”

Reticular tissue

macrophages are capable of phagocytosis.
plasmocytes (plasma cells) synthesize antibodies - gamma globulins and provide humoral immunity.
tissue basophils - produce heparin, which prevents blood clotting.

Cells and their derivatives combine into tissues. Tissue is a historically developed system of cells and intercellular substance, united by origin, structure and functions. The structure and function of tissues is studied by histology.

In the human body, 4 types of tissues are distinguished: epithelial, connective, muscle, and nervous.

Type of fabric	Structural features	Functions	Location
Epithelial	The cells are tightly pressed, the intercellular substance is poorly developed	Barrier, dividing, protective, secretory, excretory, sensory	Integuments, mucous membranes, glands
Connecting	Tissue cells are surrounded by a developed intercellular substance containing fibers, bone plates, fluid	Supporting, protective, nutritional, transport, protective, regulatory, respiratory	Bones, cartilage, tendons, blood and lymph, subcutaneous fat, brown fat
Muscular	The striated muscles are represented by multinucleated fibers, smooth muscles are formed by short mononuclear fibers. Muscle tissue is excitable and contractile	Body movement - contraction of the heart, contraction of internal organs, changes in the lumen of blood vessels	Skeletal muscles, heart, smooth muscles of internal organs, walls of blood vessels
Nervous	Consists of nerve cells - neurons and auxiliary cells (neuroglia). A neuron usually has one long process - an axon and one or more tree-like branching processes - a dendrite. Nerve tissue is excitable and conductive	Performs the functions of perception, conduction and transmission of excitation received from the external environment and internal organs, analysis, preservation of the information received, the integration of organs and systems, the interaction of the body with the external environment.	Brain, spinal cord, nerve nodes and fibers

Organs are formed from tissues, with one of the tissues being dominant.

The epithelium can be superficial and glandular. Accordingly, the glandular produces various substances and is part of various glands (remember the endocrine system from question 30). There are many types of epithelium, a multilayer non-keratinizing and keratinizing (see question 29 skin) epithelium should be distinguished. The first one covers the mucous membrane of the oral cavity, esophagus, and the cornea of \u200b\u200bthe eye. The transitional epithelium of the bladder and urinary tract, which changes its thickness when stretched, deserves a separate discussion. The epithelium of the intestinal tract plays a huge role in our body. It is a banded columnar epithelium of the intestine. Thanks to him, parietal digestion is carried out under the action of enzymes fixed on the cell membrane.

Connective tissue is a very large group of tissues. These are bone, cartilaginous, connective tissue proper, blood, lymph, brown fat, pigment tissue.

The muscle tissue forms the striated muscles, heart muscle and smooth muscle fibers. They contain myofibrils, consisting of actin and myosin, due to the sliding of myophilamines from these proteins, muscle contraction occurs.

Nervous tissue is represented by glia and neurons. Glial cells perform supporting, trophic, protective, isolating and secretory functions. There is glia (ependiomyocytes) or simply ependyma, which lines the cerebral ventricles and the spinal canal. The surface is provided with microvilli. She participates in the formation of cerebrospinal fluid, performs supporting and delimiting functions.

Astrocytes are the main supporting elements of the central nervous system. Transport of substances from the capillary bed to the neuron is carried out. Microglia - HC macrophages, have phagocytic activity.

Oligodendrocytes - located near neurons and their processes. They are also called Schwann cells. They form the sheath of the nerve fiber (axon). Interception of ranvier through 0.3-1.5 mm. The myelin sheath provides and improves the isolated conduction of nerve impulses along the axons and participates in the metabolism of the axon. In the interceptions of Ranvier, during the passage of a nerve impulse, an increase in biopotentials occurs. Some of the non-fleshy nerve fibers are surrounded by myelin-free Schwann cells.

The structural and functional unit of the organs of the nervous system is a neuron with processes extending from it. The processes of the nerve cell are divided into an axon (axial process) and tree-branching dendrites. Usually several dendrites extend from the body of the neuron. Dendrites perceive excitement and conduct them to the cell body. The axon, which departs from the cell in the singular, is characterized by uniform thickness and regular contour. He can give off branches (collaterals), which transmit impulses from the body of his cell and other cells. The nerve impulse is directed along the axon from the cell body. A synapse is a specialized connection between two neurons. It provides the transmission of excitement. The most common synapse is chemical, transmission is carried out using a neurotransmitter - a chemical. Synapses can be axo-dendritic (between the axon and the dendrite of neurons), axo-axonal (between two axons of neurons), axosomatic (between the axon and the soma or the body of neurons). There may also be axovascular synapses, between the axons of the hypothalamic neurosecretory cells and the capillary wall, which ensure the flow of neurohormone into the blood. There are neuromuscular synapses between the motor neuron axon and skeletal muscle fiber. There may be neurosecretory synapses between the nerve and the exocrine or endocrine gland.

Epithelial tissue, or epithelium, covers the outside of the body, lines the body cavities and internal organs, and also forms most of the glands.

Varieties of the epithelium have significant structural variations, depending on the origin (epithelial tissue develops from all three germ layers) of the epithelium and its functions.

However, all species have common features that characterize epithelial tissue:

The epithelium is a layer of cells, due to which it can protect the underlying tissues from external influences and exchange between the external and internal environment; violation of the integrity of the reservoir leads to a weakening of its protective properties, to the possibility of infection.
It is located on the connective tissue (basement membrane), from which nutrients are supplied to it.
Epithelial cells are polarized, i.e. parts of the cell (basal), lying closer to the basement membrane, have one structure, and the opposite part of the cell (apical) has another; different components of the cell are located in each part.
Possesses a high ability to regenerate (recover). Epithelial tissue does not contain intercellular substance or contains very little of it.

Epithelial tissue formation

Epithelial tissue is made up of epithelial cells that are tightly connected to each other and form a continuous layer.

Epithelial cells are always found on the basement membrane. It delimits them from the loose connective tissue, which lies below, performing a barrier function, and prevents the germination of the epithelium.

The basement membrane plays an important role in the trophism of epithelial tissue. Since the epithelium is devoid of blood vessels, it receives nutrition through the basement membrane from the vessels of the connective tissue.

Classification by origin

Depending on the origin, the epithelium is divided into six types, each of which occupies a certain place in the body.

Cutaneous - develops from the ectoderm, localized in the oral cavity, esophagus, cornea, and so on.
Intestinal - develops from the endoderm, lines the stomach, the small intestine and the large intestine
Coelomic - develops from the ventral mesoderm, forms serous membranes.
Ependymoglial - develops from the neural tube, lines the brain cavity.
Angiodermal - develops from the mesenchyme (also called the endothelium), lining the blood and lymph vessels.
Renal - develops from the intermediate mesoderm, occurs in the renal tubules.

Features of the structure of epithelial tissue

According to the shape and function of the cells, the epithelium is divided into flat, cubic, cylindrical (prismatic), ciliated (ciliated), as well as single-layer, consisting of one layer of cells, and multilayer, consisting of several layers.

Table of functions and properties of epithelial tissue
Epithelium type	Subtype	Location	Functions
Unilamellar uniserial epithelium	Flat	Blood vessels	BAS secretion, pinocytosis
	Cubic	Bronchioles	Secretory, transport
	Cylindrical	Gastrointestinal tract	Protective, adsorption of substances
Single layer multi-row	Columnar	The vas deferens, the duct of the epididymis	Protective
Single layer multi-row	Pseudo stratified ciliated	Respiratory tract	Secretory, transport
Multilayer	Transitional	Ureter, bladder	Protective
	Flat non-keratinizing	Oral cavity, esophagus	Protective
	Flat keratinizing	Skin	Protective
	Cylindrical	Conjunctiva	Secretory
	Cubic	Sweat glands	Protective

Single layer

Single layer flat the epithelium is formed by a thin layer of cells with uneven edges, the surface of which is covered with microvilli. There are mononuclear cells, as well as with two or three nuclei.

Single layer cubic consists of cells with the same height and width, characteristic of the glands excretory duct. The single-layer columnar epithelium is divided into three types:

Bordered - found in the intestines, gallbladder, has adsorbing properties.
Ciliated - is characteristic of the oviducts, in the cells of which there are mobile cilia at the apical pole (they contribute to the movement of the egg).
Glandular - localized in the stomach, produces a mucous secret.

Single layer multi-row the epithelium lines the respiratory tract and contains three types of cells: ciliated, intercalated, goblet and endocrine. Together they ensure the normal functioning of the respiratory system, protect against the ingress of foreign particles (for example, the movement of cilia and mucous secretions help to remove dust from the respiratory tract). Endocrine cells produce hormones for local regulation.

Multilayer

Multilayer flat non-keratinizing the epithelium is located in the cornea, anal rectum, etc. Three layers are distinguished:

The basal layer is formed by cells in the form of a cylinder, they divide in a mitotic way, some of the cells belong to the stem;
spinous layer - cells have processes that penetrate between the apical ends of the cells of the basal layer;
a layer of flat cells - located outside, constantly dying off and peeling off.

Stratified epithelium

Multilayer flat keratinizing the epithelium covers the surface of the skin. There are five different layers:

Basal - formed by poorly differentiated stem cells, together with pigment - melanocytes.
The spinous layer together with the basal layer form the growth zone of the epidermis.
The granular layer is built of flat cells, in the cytoplasm of which the keratoglian protein is located.
The shiny layer got its name from its characteristic appearance during microscopic examination of histological preparations. It is a homogeneous shiny strip, which stands out due to the presence of elaidin in flat cells.
The stratum corneum consists of horny scales filled with keratin. The scales that are closer to the surface are susceptible to the action of lysosomal enzymes and lose their connection with the underlying cells, therefore they constantly peel off.

Transitional epithelium is located in the renal tissue, urinary tract, bladder. Has three layers:

Basal - consists of cells with intense coloration;
intermediate - with cells of various shapes;
integumentary - has large cells with two or three nuclei.

It is common for the transitional epithelium to change shape depending on the state of the organ wall; they can flatten or acquire a pear-shaped shape.

Special types of epithelium

Aceto-white -it is an abnormal epithelium that becomes intensely white when exposed to acetic acid. Its appearance during colposcopic examination makes it possible to identify the pathological process in the early stages.

Buccal -collected from the inner surface of the cheek, is used for genetic examination and the establishment of family ties.

Functions of epithelial tissue

Located on the surface of the body and organs, the epithelium is a border tissue. This situation determines its protective function: protection of the underlying tissues from harmful mechanical, chemical and other influences. In addition, metabolic processes occur through the epithelium - the absorption or excretion of various substances.

The epithelium, which is part of the glands, has the ability to form special substances - secrets, and also to release them into the blood and lymph or into the ducts of the glands. This epithelium is called secretory, or glandular.

Differences between loose fibrous connective tissue and epithelial

Epithelial and connective tissue perform different functions: protective and secretory in the epithelium, supporting and transport in connective tissue.

The cells of the epithelial tissue are tightly interconnected, there is practically no intercellular fluid. There is a large amount of intercellular substance in the connective tissue, the cells are not tightly connected to each other.

Biology lesson in grade 8 Lesson number 6

Lesson topic: Basic human tissues. Epithelial and connective tissue.

The purpose of the lesson: to give a general idea of \u200b\u200bthe variety of tissues in the human body and their functions;

Lesson objectives:

Educational: to reveal the concept of the tissues of a multicellular animal organism and the classification of tissues.

At the level of the periodontal ligament, there may be some structural changes due to various trauma or forces that can be applied in the occlusal areas. One of these changes can be a ligament rupture, which accompanies hemorrhage, necrosis, destruction or resorption of blood vessels and bone resorption. Thus, in this situation, the tooth loses significantly from the attachment that holds it in the alveoli and becomes weak. The repair process can happen quickly due to the specific properties of collagen.

Vascularization of the periodontal ligament

The cells that the periodontal ligament adheres to are: fibroblasts, osteoblasts, osteoclasts, cementoblasts, Malassi cell debris, macrophages, cells associated with vascular and neural structures. Blood lightening Provided by the upper and lower alveolar arteries, which flow into the alveolar bone, taking the form of the interalveolar arteries.

Developing: develop the ability to compare the structural features of tissues in connection with the functions performed.

Educational: to foster the spirit of competition, quick thinking, the ability to analyze, to carry out aesthetic education.

Equipment: drawings "Human cell",

Teaching method: verbal, explanatory and illustrative.

Innervation of the periodontal ligament

Functions performed by the periodontal ligament

The structure of the alveolar processes. The actual alveolar bone, also called hard lamellae or crushed stone laminate, is the bony portion of the attachment of the ligament fibers and coincides with the facial bone. The alveolar abutment bone includes both the cancellous and the cortical plate and represents the outer body and the limit of the alveolar process.

With age, the loss of teeth leads to the formation of narrow jaws, which leads to a reduction in processes, which ultimately leads to a loss of bone mass. Alveolar processes are extremely sensitive to the transmission of sensations of pressure and tension, which by their nature stimulate the process of bone formation.

Predicted result:students will study the tissues of the human body.

Lesson type:revealing the content of the topic.

Lesson type: combined.

Lesson plan:

1. Organization of the class.

2. Checking homework.

4. Homework.

5. Viewing a segment of a video

During the classes:

Fasciitis bone. It occurs in the dental follicle and is the point of attachment of fiber bundles in the periodontal ligament. The name of the fascicular bone is associated with Shar-Pei fibers and numerous perforations that lead to the formation of vascular and nerve elements, therefore it is called a crypt-like plate.

Spongy bone Located between the cortical plate and the fascicular bone. It occupies the middle of the alveolar processes and is trabecular in nature. Cortical plate It is located on the surface of the alveolar processes and extends from the alveolar ridge to the lower limits of the alveoli. It is finely fibrillated thin bone, consisting of longitudinal lamellas, Haversian canals, which together form Haversian systems of thickness that vary considerably.

1. Organization of the class:

I come in. Hello. I check the attendance. I report the topic of the lesson and the plan of work for the lesson.

2. Checking homework:

Retelling of the theme “Cell organelles. The chemical composition of the cell "and independent work (Notebook with tasks for individual work, grade 8, part 1, page 6)

3. Learning new material.

Vulcanization of alveolar processes

Functions of alveolar processes

Signs that can occur at the periodontal level. Changes in the contour of the gums, which can occur in the form of: recession, true or false periodontal pockets, fracture lesions. They are caused by swelling and swelling of the mucous membranes of the gums or a decrease in resin volume.

Volume changes in the gingival mucosa. A decrease in volume, which can be physiological or pathological. Physiological due to the aging process, and pathological due to dystrophic forms of periodontopathy. The increase in volume is associated with gingival hyperplasia and hypertrophy.

In human and animal bodies, individual cells or groups of cells, adapting to the performance of various functions, differentiate, i.e. change their forms and structure accordingly, remaining at the same time interconnected and subordinate to a single integral organism. This process of continuous development of cells leads to the emergence of many different types of cells that make up human tissue.

You know that the human body, like all living organisms, consists of cells. The cells are not randomly arranged. They are connected by the intercellular substance, grouped and form tissues. Tissue is a collection of cells that are identical in origin, structure and functions. Tissues are divided into 4 groups: epithelial, connective, muscular and nervous.

Epithelial tissue (from the Greek epi - surface), or epithelium, forms the upper layer of the skin (only a few cells thick), mucous membranes of internal organs (stomach, intestines, excretory organs, nasal cavity), as well as some glands. The cells of the epithelial tissue are closely adjacent to each other. Thus, it plays a protective role and protects the body from harmful substances and microbes entering it. Cell shapes are varied: flat, tetrahedral, cylindrical, etc. The structure of the epithelium can be single-layer and multilayer. So, the outer layer of the skin is multilayer. When it peels off, the upper cells die off and are replaced by internal ones, the next.

Depending on the function performed, the epithelium (Fig. 3) is divided into the following groups:

glandular epithelium - cells secrete milk, tears, saliva, sulfur;

ciliated epithelium of the respiratory tract retains dust and other foreign bodies with the help of mobile cilia. Hence its other name - ciliated;

the stratified integumentary epithelium covers the surface of the skin and the oral cavity, lines the esophagus from the inside; single-layer tetrahedral (cubic) - lining the renal tubules from the inside; cylindrical - lining the stomach and intestines from the inside;

the sensitive epithelium perceives excitement. For example, the olfactory epithelium of the nasal cavity is very sensitive to odors.

Functions of epithelial tissue:

1) protects the tissues underneath;

2) regulates the constancy of the internal environment of the body;

3) participates in the metabolism at the initial and final stages;

4) regulates metabolism, etc.

Connective tissue. Connective tissue is formed by blood, lymph, bones, fat, cartilage, tendons, ligaments. By structure, connective tissue is subdivided into dense fiber, cartilaginous, bone, loose fiber, blood and lymph (Fig. 4).

Dense-fibrous tissue - cells are located close to each other, there is a lot of intercellular substance, a lot of fibers. It is located in the skin, in the walls of blood vessels, ligaments and tendons.

Cartilage tissue - spherical cells, arranged in bundles. There is a lot of cartilage tissue in the joints, between the vertebral bodies. The epiglottis, pharynx, and auricle are also made of cartilage.

Bone. It contains calcium salts and protein. Bone connective tissue cells are alive, surrounded by blood vessels and nerves. The structural unit of bone tissue is osteon. It consists of a system of bone plates in the form of cylinders inserted into each other. Between them are bone cells - osteocytes, and in the center - nerves and blood vessels. Skeletal bones are composed entirely of this tissue.

Loose-fiber fabric. The fibers are intertwined with each other, the cells are located close to each other. Surrounds blood vessels and nerves, fills the space between organs. Bonds skin to muscles. Under the skin it forms a loose tissue - subcutaneous fatty tissue.

Blood and lymph are fluid connective tissue.

Connective tissue functions:

1) gives strength to fabrics (dense fiber fabric);

2) forms the basis of the tendons and skin (dense tissue);

3) performs a supporting function (cartilage and bone tissue);

4) provides transportation of nutrients and oxygen (blood, lymph) throughout the body.

4. Watch a video clip

Disc "Human Anatomy"

5. Homework

(retelling § 7)

6. Lesson summary and grading.

What conclusion did you draw at the end of our lesson?

Tissues are a collection of cells and non-cellular structures (non-cellular substances) that are similar in origin, structure, and functions. There are four main groups of tissues: epithelial, muscle, connective and nervous.

... Epithelial tissues cover the body from the outside and line the hollow organs and walls of body cavities from the inside. A special type of epithelial tissue - glandular epithelium - forms most of the glands (thyroid, sweat, liver, etc.).

… Epithelial tissues have the following features: - their cells are closely adjacent to each other, forming a layer; - there is very little intercellular substance; - cells have the ability to recover (regenerate).

... Epithelial cells in shape can be flat, cylindrical, cubic. By the number of layers of the epithelium, there are single-layer and multi-layer.

… Examples of epithelium: single-layer flat epithelium lines the chest and abdomen of the body; multi-layered flat forms the outer layer of the skin (epidermis); monolayer cylindrical lines most of the intestinal tract; multilayer cylindrical - the cavity of the upper respiratory tract); monolayer cubic forms the tubules of the nephrons of the kidneys. Functions of epithelial tissues; borderline, protective, secretory, suction.

CONNECTING TISSUE PROPERLY CONNECTING SKELETAL Fibrous Cartilaginous 1. loose 1. hyaline cartilage 2. dense 2. elastic cartilage 3. formalized 3. fibrous cartilage 4. unformed With special properties Bone 1. reticular 1. coarse fibrous 2. fatty 2. lamellar: 3. mucous compact substance 4.pigmented spongy substance

... Connective tissues (tissues of the internal environment) unite groups of tissues of mesodermal origin, which are very different in structure and function. Types of connective tissue: bone, cartilaginous, subcutaneous fatty tissue, ligaments, tendons, blood, lymph, etc.

… Connective tissues A common characteristic feature of the structure of these tissues is a loose arrangement of cells, separated from each other by a well-defined intercellular substance, which is formed by various proteins of a protein nature (collagen, elastic) and the main amorphous substance.

... Blood is a kind of connective tissue, in which the intercellular substance is liquid (plasma), due to which one of the main functions of blood is transport (carries gases, nutrients, hormones, end products of the vital activity of cells, etc.).

... The intercellular substance of loose fibrous connective tissue located in the layers between the organs, as well as connecting the skin with the muscles, consists of an amorphous substance and elastic fibers freely located in different directions. Due to this structure of the intercellular substance, the skin is mobile. This fabric has a supporting, protective and nourishing function.

... Muscle tissues determine all types of motor processes inside the body, as well as the movement of the body and its parts in space.

... This is due to the special properties of muscle cells - excitability and contractility. All cells of muscle tissue contain the finest contractile fibers - myofibrils, formed by linear protein molecules - actin and myosin. When they slide relative to each other, the length of the muscle cells changes.

... Transversely striated (skeletal) muscle tissue is built of many multinucleated fiber-like cells 1-12 cm long. All skeletal muscles, muscles of the tongue, walls of the oral cavity, pharynx, larynx, upper part of the esophagus, mimic, diaphragm are built from it. Figure 1. Fibers of striated muscle tissue: a) appearance of the fibers; b) cross section of fibers

... Peculiarities of striated muscle tissue: speed and arbitrariness (ie, the dependence of contraction on the will, desire of a person), consumption of large amounts of energy and oxygen, rapid fatigability. Figure 1. Fibers of striated muscle tissue: a) the appearance of the fibers; b) cross section of fibers

... The heart tissue consists of transversely striated mononuclear muscle cells, but has different properties. The cells are not arranged in a parallel bundle, like skeletal cells, but branch, forming a single network. Thanks to the many cell contacts, the incoming nerve impulse is transmitted from one cell to another, providing simultaneous contraction and then relaxation of the heart muscle, which allows it to perform a pumping function.

… Cells of smooth muscle tissue do not have cross striation, they are fusiform, mononuclear, their length is about 0.1 mm. This type of tissue is involved in the formation of the walls of tubular internal organs and blood vessels (digestive tract, uterus, bladder, blood and lymph vessels).

... Nerve tissue, from which the brain and spinal cord, nerve nodes and plexuses, peripheral nerves are built, performs the functions of perception, processing, storage and transmission of information from both the environment and the organs of the organism itself. The activity of the nervous system provides the body's reactions to various stimuli, regulation and coordination of the work of all its organs.

... Neuron - consists of a body and processes of two types. The body of a neuron is represented by the nucleus and the surrounding cytoplasm. It is the metabolic center of the nerve cell; when it is destroyed, it dies. The bodies of neurons are located mainly in the brain and spinal cord, that is, in the central nervous system (CNS), where their clusters form the gray matter of the brain. Clusters of nerve cell bodies outside of the central nervous system form nerve nodes, or ganglia.

Figure 2. Different shapes of neurons. a - a nerve cell with one process; b - a nerve cell with two processes; c - a nerve cell with a large number of processes. 1 - cell body; 2, 3 - processes. Figure 3. Diagram of the structure of the neuron and nerve fiber 1 - the body of the neuron; 2 - dendrites; 3 - axon; 4 - axon collaterals; 5 - myelin sheath of the nerve fiber; 6 - terminal branching of the nerve fiber. The arrows show the direction of propagation of nerve impulses (according to Polyakov).

… The main properties of nerve cells are excitability and conductivity. Excitability is the ability of the nervous tissue to enter a state of excitement in response to irritation.

... conduction is the ability to transmit excitation in the form of a nerve impulse to another cell (nervous, muscular, glandular). Thanks to these properties of the nervous tissue, perception, conduct and formation of the body's response to the action of external and internal stimuli are carried out.