Objective of laboratory work No. 1:
Study the structural features various types epithelial tissues.
Equipment and materials: laboratory microscope, histological preparations:
Single-layer single-row squamous epithelium (cat omental mesothelium)
Single layer single row cuboidal epithelium (rabbit kidney)
Single-layer single-row prismatic epithelium (rabbit kidney)
Single-layer single-row prismatic bordered epithelium (toothless intestine)
Stratified squamous non-keratinizing epithelium (cornea of the cow eye)
Stratified squamous keratinizing epithelium (skin of a human finger)
Laboratory work designed for 5 classroom hours.
Progress:
1. Consider drug 1.
Single-layer single-row squamous epithelium (mesothelium) (Fig. 1.3). Impregnation with silver nitrate. Nuclei are stained with hematoxylin.
The drug is a piece of omentum, its basis is connective tissue, covered on both sides with mesothelium. Holes are visible in the seal film. At low microscope magnification, find the place where the layer connective tissue thinner and clear cell boundaries are visible.
Study the drug at high magnification. The cell boundaries are uneven, the teeth of one cell correspond to the notches of another. It is noticeable that the cells are pressed very tightly against each other, the intercellular space is minimal. The nuclei of epithelial cells are round and are usually located in the center of the cell. Some mesothelial cells appear binucleate. This is due to the fact that against the background of the cytoplasm of superficial cells, the nuclei of deep-lying cells are visible.
2. Draw and label: 1) boundaries of mesothelial cells; 2) nuclei of epithelial cells; 3) cytoplasm.
3.Consider drug 2
. Single-layer single-row cubic or single-layer single-row prismatic epithelium (rabbit kidney) (Fig. 1.4). Hematoxylin-eosin staining.
At low magnification of the microscope, many large oval-shaped tubules are visible. Find cross sections of renal tubules that look like round or oval flat formations lined with single-layer epithelium. Depending on the caliber of the tubule, the epithelium can be of different heights - from prismatic to cubic (mainly cuboidal epithelium). Beneath the epithelium is loose connective tissue rich in blood vessels.
View the cells at high magnification. Please note that the epithelial cells are approximately the same height and width, and the cell nuclei are round. The epithelium and connective tissue are separated by a basement membrane.
4. Sketch and label: 1) nuclei of epithelial cells; 2) basement membrane; 3) apical and basal ends of epithelial cells; 4) lumen of the renal tubule; 5) cells and intercellular substance of connective tissue.
5. Consider drug 3. Single-layer single-row prismatic bordered epithelium (edentulous intestine) (Fig. 1.5). Hematoxylin-eosin staining.
With a low magnification of the microscope, find the dark border of the epithelium lining the intestinal tube and switch to high magnification. Narrow long cells of the ciliated epithelium are visible, located on the basement membrane. The nuclei of epithelial cells are dark-colored, oval in shape, and lie in one row in the basal part of the cells. On the apical surface of prismatic epithelial cells, you can see a light gray border consisting of cilia - the brush border.
Between the epithelial cells, goblet cells are sometimes found that secrete mucus onto the surface of the intestine. They are lighter. The nuclei are flattened and located at the base of the cells.
6. Sketch and label: 1) nuclei of epithelial cells; 2) brush border; 3) goblet cells; 4) basement membrane; 5) underlying connective tissue.
7. Consider drug 4. Stratified squamous non-keratinizing epithelium (cornea of a cow's eye) (Fig. 1.6). Hematoxylin-eosin staining.
At low microscope magnification, orient the specimen so that the epithelial layer is in the upper part of the section. The border of the epithelium with the connective tissue is a straight line. Select a section of the epithelium in which the cell boundaries are clearly visible and examine it at high magnification. It is clearly visible that the epithelium consists of several rows of cells different shapes. On the basement membrane there are cylindrical cells with elongated, vertically located nuclei. These cells form the basal layer of the epithelium. Epithelial cells of the basal layer regularly divide mitotically, creating a reserve of cells. Gradually, the cells of the basal layer move to the surface and turn into large polygonal cells of the spinous layer, and then acquire a flat shape and form a layer of flat cells (superficial layer). Squamous cells have rod-shaped nuclei and form several layers parallel to the surface of the epithelium. Note the gradual (from the basal layer of cells to upper layers epithelial cells) change in the shape of the nucleus, expressed in its flattening.
8. Sketch and label: 1) cells and intercellular substance of connective tissue; 2) basement membrane; 3) basal layer of epithelial cells; 4) layer of spinous cells; 5) layer of flat cells.
9. Consider drug 5. Stratified squamous keratinizing epithelium (skin of a human finger) (Fig. 1.7). Hematoxylin-eosin staining.
At low microscope magnification, orient the specimen so that the epithelial layer is in the upper part of the section. The boundary between the epithelium and connective tissue has the shape of a strongly curved curve. The epidermis on the preparation is dark, and the connective tissue part of the skin is light. Pay attention to the relationship between the epithelial layer and the underlying connective tissue, which extends deeply into the thickness of the epithelium, forming its papillae, rich in blood vessels. An uneven border provides significant
increasing the contact surface of the epidermis and connective tissue, which improves the nutrition of the epithelium and increases the adhesion strength of these tissues.
Find a section of the epidermis cut strictly vertically and examine it at high magnification.
The epidermis has 5 layers: basal, spinous, granular, shiny and horny. The cells of the basal layer are prismatic in shape, lie on the basement membrane, and regularly divide mitotically. The cells of the spinous layer are process-shaped and retain the ability to divide. As epithelial cells grow, they undergo keratinization. The granular layer (dark-colored) is formed by 2-3 rows of elongated cells; the cytoplasm contains grains of the keratohyalin protein, which is then converted into the eleidin protein, detected in the degenerating cells of the stratum pellucida. The stratum pellucida is light in color, the boundaries of the cells of this layer are almost invisible, and the nuclei are not visible. The most superficial and thickest layer of the epithelial layer is the stratum corneum. It consists of dead keratinized cells that look like nuclear-free scales that gradually peel off from the surface of the skin. In the stratum corneum, openings located one above the other may be noticeable - sections of corkscrew-shaped ducts of the sweat glands located outside the epidermis in the connective tissue part of the skin.
10. Sketch and label: 1) cells and intercellular substance of connective tissue; 2) basement membrane; 3) basal layer of epithelial cells (germ layer); 4) layer of spinous cells; 5) granular layer; 6) stratum lucidum 7) stratum corneum.
Control questions and tasks for independent work
1. Characterize common features the structure of all epithelia. 2. What characteristics is the morphofunctional classification of integumentary epithelium based on? 3. Describe single-layer epithelia according to the diagram: location in the body, structural features, functions. 4. Describe multilayer epithelia according to the diagram: location in the body, structural features, functions. 5. Regeneration of integumentary epithelium. 6. Derivatives of epithelium - nails, hair. 7. Give a general description of glandular epithelia. 8. Describe the phases of glandulocyte secretion. 9. What is the main difference between endocrine and exocrine glands? 10. What features is the morphofunctional classification based on? exocrine glands? 11. Regeneration and age-related features of the glandular epithelium.
Exercise 1. Examine and sketch preparations 1,2,3,4,5.
| Drug No. 1. Multilayer squamous epithelium. Cornea of the eye. Hematoxylin–eosin. | |
| At low magnification, look at the two parts. One is colored blue-violet - this is multilayered epithelium, the second part is represented by connective tissue, and is colored pink. Between them you can see a fairly thick uncolored layer - this is the basement membrane. At high magnification, you can count from 10 to 13 rows of cells. The lowest layer is formed by one row of prismatic cells with an oval-shaped nucleus and is connected to the basal membrane using hemidesmosomes. Stem cells and differentiating cells are found here. Then there are cells of almost cubic shape. Wedged between them are spiny cells of irregular polygonal shape with rounded nuclei. | Multilayered squamous (non-keratinizing) epithelium of the cornea: 1- flat cells of the apical layer; 2- cells of the middle layer; 3- cells of the basal layer; 4- basement membrane; 5- corneal substance (connective tissue) The following rows gradually flatten. Light spaces – intercellular gaps – are clearly visible between the cells. These cells slough off over time. There are no blood vessels in the epithelial layers. |
| Drug No. 2. Tall prismatic (cylindrical) epithelium. Rabbit kidney. Hematoxylin-eosin | ||
| At low magnification, the kidney tubules are clearly visible, cut into various directions. Depending on how they were cut, the tubules can be in the form of circles or ovals and have a lumen of varying sizes. Connective tissue fibers are visible between the tubules and blood vessels. Under high magnification you should find a cross section of the renal tubule, where a number of tall cylindrical cells adjacent closely to each other are clearly visible. The cells are located on a thin basement membrane. Cells have basal and apical edges. The nucleus lies closer to the basal part of the cell. Draw a cross-section of one tubule, indicating the listed structures. |  Single-layer cylindrical epithelium of the collecting ducts of the kidney: 1- cylindrical cells; 2- basement membrane; 3- connective tissue and vessels surrounding the tubes
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| Drug No. 3. Low prismatic epithelium. Rabbit kidney. Hematoxylin-eosin. | ||
| On the preparation at low magnification, find a cross section of the renal tubules. The size of the lumen may vary. Epithelial cells are arranged in one row and fit very tightly to each other, forming a continuous layer. Determine the shape of epithelial cells by comparing their width and height. Between the cells in the apical part, end plates can be seen. The nuclei are round, large and lie closer to the basal part and almost at the same level. The basement membrane separates the epithelial cells from the underlying connective tissue. In connective tissue large quantities there are blood capillaries. Examine the specimen under high magnification, examine the basement membrane, |  Low prismatic epithelium of rabbit renal tubules: 1-lumen of the tubule; 2 – prismatic cells; 3 – basement membrane; 4 – connective tissue and vessels surrounding the tubules. having the appearance of a thin oxyphilic border on the outside of the tubule, consider the cytoplasm and nuclei of epithelial cells. Draw a cross-section of one tubule, indicating the listed structures. |
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| Drug No. 4. Single-layer squamous epithelium (mesothelium). Impregnation with silver nitrate + hematoxylin. Total drug | |
| A total film preparation of the intestinal mesentery, in which the lateral borders of tightly adjacent epithelial cells of irregular shape were revealed by impregnation with silver nitrate. The thinnest parts of the preparation are painted light yellow, and the convoluted borders of the cell (1) are painted black. The cell contains one or two nuclei. This is due to the fact that the mesentery consists of two layers of epithelium, and between them there is a thin layer of connective tissue. Nuclei (2) are counterstained with hematoxylin. Examine the preparation under high magnification and draw 5-6 cells, indicating the tortuous cell boundaries, nuclei and cytoplasm |
 Single-layer squamous epithelium (mesothelium) of the omentum: 1-epithelial cells; a-cytoplasm; b-core;
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| Drug No. 5. Transitional epithelium. Rabbit bladder. Hematoxylin-eosin. | |
| The specimen is a cross-section of the bladder wall. The inside of the wall is lined with transitional epithelium. The epithelial layer forms folds. Examine the preparation at low magnification. The epithelial layer is represented by several layers of cells: the basal layer, the intermediate layer and the superficial layer. Intermediate layer cells various shapes(round, cubic and irregular polygonal, and on the surface - elongated if the layer is not stretched), some of them are binuclear. The lowest layer of the epithelial layer is separated from the connective tissue by a thin basement membrane. | 
Transitional epithelium of the bladder (epithelium with an unstretched organ wall): 1- superficial cells with a cuticle on the surface; 2- cells of the intermediate layers of the epithelium; 3- cells of the basal layer of the epithelium; 4- loose connective tissue A blood vessel can be seen located in the loose connective tissue (4). |
INDEPENDENT WORK.
Exercise 1. Draw a diagram of the structure of a desmosome, hemidesmosome and its relationship with the basement membrane, noting the main chemical components of these structures.
Task 2. Draw up a diagram of the morphological classification of epithelia, giving relevant examples.
Recommended further reading.
1. Shubnikova E.A. Epithelial tissues.-M.: Publishing house of Moscow State University, 1996.-256 p.
2. Ham A., Cormack D. Histology.-M., Mir, 1983.-T.2.-P.5-34.
Laboratory work No. 2
Topic: Epithelial tissues. Glandular epithelium. Exocrine glands
Purpose of the lesson.
After self-study theoretical material and work on practical lesson the student must know:
1..Characteristics of glandular epithelial cells, features of their structure.
2.Classifications and typical examples various types of glands.
3. Secretory cycle of glandular epithelial cells, its morphofunctional characteristics and structure various types secretory cells.
Topic study plan
Glandular epithelia
Definitions and classification
Types of secretion
Merocrine
Apocrine
Holocrine
Epithelial tissues communicate the body with external environment. They perform integumentary and glandular (secretory) functions.
The epithelium is located in skin, lines the mucous membranes of all internal organs, is part of the serous membranes and lines the cavities.
Epithelial tissues perform various functions - absorption, excretion, perception of irritations, secretion. Most of the body's glands are made of epithelial tissue.
All germ layers take part in the development of epithelial tissues: ectoderm, mesoderm and endoderm. For example, the epithelium of the skin of the anterior and posterior sections of the intestinal tube is a derivative of ectoderm, the epithelium of the middle section of the gastrointestinal tube and respiratory organs is of endodermal origin, and the epithelium of the urinary system and reproductive organs is formed from mesoderm. Epithelial cells are called epithelial cells.
To the main general properties epithelial tissues include the following:
1) Epithelial cells fit tightly to each other and are connected by various contacts (using desmosomes, closure bands, gluing bands, slits).
2) Epithelial cells form layers. There is no intercellular substance between the cells, but there are very thin (10-50 nm) intermembrane gaps. They contain the intermembrane complex. Substances entering and secreted by cells penetrate here.
3) Epithelial cells are located on the basement membrane, which in turn lies on loose connective tissue that nourishes the epithelium. basement membrane up to 1 micron thick, it is a structureless intercellular substance through which nutrients come from blood vessels located in the underlying connective tissue. Both epithelial cells and loose connective underlying tissue participate in the formation of basement membranes.
4) Epithelial cells have morphofunctional polarity or polar differentiation. Polar differentiation is different structure superficial (apical) and lower (basal) poles of the cell. For example, at the apical pole of some epithelial cells, the plasmalemma forms an absorptive border of villi or ciliated cilia, and the basal pole contains the nucleus and most organelles.
In multilayer layers, the cells of the superficial layers differ from the basal ones in shape, structure and function.
The polarity indicates that different areas cells are committed various processes. The synthesis of substances occurs at the basal pole, and at the apical pole absorption, movement of cilia, and secretion occur.
5) Epithelia have a well-expressed ability to regenerate. When damaged, they quickly recover through cell division.
6) There are no blood vessels in the epithelium.
Classification of epithelia
There are several classifications of epithelial tissues. Depending on the location and function performed, two types of epithelia are distinguished: integumentary and glandular .
The most common classification of integumentary epithelium is based on the shape of the cells and the number of their layers in the epithelial layer.
According to this (morphological) classification integumentary epithelia divided into two groups: I) single-layer and II) multi-layer .
IN single-layer epithelia the lower (basal) poles of the cells are attached to the basement membrane, and the upper (apical) poles border on the external environment. IN stratified epithelia only the lower cells lie on the basement membrane, all the rest are located on the underlying ones.
Depending on the shape of the cells, single-layer epithelia are divided into flat, cubic and prismatic, or cylindrical . In squamous epithelium, the height of the cells is much less than the width. This epithelium lines the respiratory sections of the lungs, the cavity of the middle ear, some sections of the renal tubules, and covers all the serous membranes of the internal organs. Covering the serous membranes, epithelium (mesothelium) participates in the secretion and absorption of fluid into the abdominal cavity and back, and prevents the fusion of organs with each other and with the walls of the body. By creating a smooth surface of the organs lying in the chest and abdominal cavity, provides the ability to move them. The epithelium of the renal tubules is involved in the formation of urine, the epithelium of the excretory ducts performs a delimiting function.
Due to the active pinocytotic activity of squamous epithelial cells, substances are rapidly transferred from the serous fluid to the lymphatic bed.
The single-layer squamous epithelium covering the mucous membranes of organs and serous membranes is called lining.
Single layer cuboidal epithelium lines the excretory ducts of the glands, kidney tubules, forms follicles thyroid gland. The height of the cells is approximately equal to the width.
The functions of this epithelium are related to the functions of the organ in which it is located (in the ducts - delimiting, in the kidneys osmoregulatory, and other functions). Microvilli are located on the apical surface of cells in the kidney tubules.
Single-layer prismatic (cylindrical) epithelium has a greater cell height compared to width. It lines the mucous membrane of the stomach, intestines, uterus, oviducts, collecting ducts of the kidneys, excretory ducts of the liver and pancreas. Develops mainly from the endoderm. The oval nuclei are shifted to the basal pole and are located at the same height from the basement membrane. In addition to the delimiting function, this epithelium performs specific functions inherent in one or another organ. For example, the columnar epithelium of the gastric mucosa produces mucus and is called mucous epithelium, the intestinal epithelium is called edged, since at the apical end it has villi in the form of a border, which increase the area of parietal digestion and absorption nutrients. Each epithelial cell has more than 1000 microvilli. They can only be considered in electron microscope. Microvilli increase the absorption surface of the cell up to 30 times.
IN epithelia, lining the intestines are goblet cells. These are single-celled glands that produce mucus, which protects the epithelium from the effects of mechanical and chemical factors and promotes better movement of food masses.
Single-layer multirow ciliated epithelium lines airways respiratory organs: nasal cavity, larynx, trachea, bronchi, as well as some parts of the reproductive system of animals (vas deferens in males, oviducts in females). The epithelium of the airways develops from the endoderm, the epithelium of the reproductive organs from the mesoderm. Single-layer multirow epithelium consists of four types of cells: long ciliated (ciliated), short (basal), intercalated and goblet. Only ciliated (ciliated) and goblet cells reach the free surface, and basal and intercalary cells do not reach the upper edge, although together with others they lie on the basement membrane. Intercalary cells differentiate during growth and become ciliated (ciliated) and goblet-shaped. Cores different types cells lie at different heights, in the form of several rows, which is why the epithelium is called multirow (pseudo-stratified).
Goblet cells are single-celled glands that secrete mucus that covers the epithelium. This promotes the adhesion of harmful particles, microorganisms, and viruses that enter with the inhaled air.
Ciliated cells on their surface they have up to 300 cilia (thin outgrowths of the cytoplasm with microtubules inside). The cilia are in constant motion, due to which, along with mucus, dust particles trapped in the air are removed from the respiratory tract. In the genitals, the flickering of cilia promotes the advancement of germ cells. Consequently, the ciliated epithelium, in addition to its delimiting function, performs transport and protective functions.
II. Stratified epithelia
1. Stratified non-keratinizing epithelium covers the surface of the cornea of the eye, oral cavity, esophagus, vagina, caudal part of the rectum. This epithelium comes from the ectoderm. It has 3 layers: basal, spinous and flat (superficial). The cells of the basal layer are cylindrical in shape. Oval nuclei are located at the basal pole of the cell. Basal cells divide mitotically, replacing dying cells of the surface layer. Thus, these cells are cambial. With the help of hemidesmosomes, basal cells are attached to the basement membrane.
The cells of the basal layer divide and, moving upward, lose contact with the basement membrane, differentiate and become part of the spinous layer. Layer spinosum formed by several layers of cells of irregular polygonal shape with small processes in the form of spines, which, with the help of desmosomes, firmly connect the cells to each other. Tissue fluid with nutrients circulates through the gaps between the cells. Thin filaments-tonofibrils are well developed in the cytoplasm of spinous cells. Each tonofibril contains thinner filaments-microfibrils. They are built from the protein keratin. Tonofibrils, attached to desmosomes, perform a supporting function.
The cells of this layer have not lost mitotic activity, but their division is less intense than that of the cells of the basal layer. Upper cells The stratum spinosum gradually flattens and moves into the superficial flat layer 2-3 rows of cells thick. The cells of the flat layer seem to spread out over the surface of the epithelium. Their kernels also become flat. Cells lose their ability to undergo mitosis and take the form of plates and then scales. The connections between them weaken and they fall off the surface of the epithelium.
2. Stratified squamous keratinizing epithelium develops from the ectoderm and forms the epidermis, covering the surface of the skin.
The epithelium of hairless skin has 5 layers: basal, spinous, granular, shiny and horny.
In the skin with hair, only three layers are well developed - basal spinous and horny.
The basal layer consists of a single row of prismatic cells, most of which are called keratinocytes. There are other cells - melanocytes and non-pigmented Langerhans cells, which are skin macrophages. Keratinocytes participate in the synthesis of fibrous proteins (keratins), polysaccharides, and lipids. The cells contain tonofibrils and grains of the melanin pigment that come from melanocytes. Keratinocytes have high mitotic activity. After mitosis, some of the daughter cells move to the superior spinous layer, while others remain in reserve in the basal layer.
The main significance of keratinocytes- formation of a dense, protective, non-living horny substance of keratin.
Melanocytes stitched shape. Their cell bodies are located in the basal layer, and processes can reach other layers of the epithelial layer.
Main function of melanocytes- education melanosomes containing skin pigment - melanin. Melanosomes enter neighboring epithelial cells along the processes of the melanocyte. Skin pigment protects the body from excessive ultraviolet irradiation. Participating in the synthesis of melanin are: ribosomes, granular endoplasmic reticulum, and Golgi apparatus.
Melanin in the form of dense granules is located in the melanosome between the protein membranes that cover the melanosomes and on the outside. Thus, melanosomes chemical composition are melanoprodeids. Cells of the spinous layer multifaceted, have uneven boundaries due to cytoplasmic projections (spines), with the help of which they are connected to each other. The stratum spinosum is 4-8 layers of cells wide. In these cells, tonofibrils are formed, which end in desmosomes and firmly connect the cells to each other, forming a supporting-protective frame. The spinous cells retain the ability to reproduce, which is why the basal and spinous layers are collectively called the germinal layer.
Granular layer consists of 2-4 rows of flat-shaped cells with a reduced number of organelles. The tonofibrils are impregnated with keratohealin substance and turned into grains. Keratinocytes of the granular layer are the precursors of the next layer - brilliant.
Shiny layer consists of 1-2 rows of dying cells. In this case, the keratogealin grains merge. Organelles degrade, nuclei disintegrate. Keratohealin transforms into eleidin, which refracts light strongly, giving the layer its name.
The most superficial stratum corneum consists of horny scales arranged in many rows. The scales are filled with the horny substance keratin. On skin covered with hair, the stratum corneum is thin (2-3 rows of cells).
So, the keratinocytes of the surface layer turn into a dense non-living substance - keratin (keratos - horn). It protects underlying living cells from strong mechanical stress and drying out.
The stratum corneum serves as the primary protective barrier, impermeable to microorganisms. The specialization of the cell is expressed in its keratinization and transformation into a horny scale containing chemically stable proteins and lipids. The stratum corneum has poor thermal conductivity and prevents the penetration of water from the outside and its loss by the body. In the process of histogenesis, sweat cells are formed from epidermal cells - hair follicles, sweat, sebaceous and mammary glands.
Transitional epithelium- originates from mesoderm. It lines the inner surfaces of the renal pelvis, ureters, bladder and urethra, i.e., organs that are subject to significant stretching when filled with urine. The transitional epithelium consists of 3 layers: basal, intermediate and superficial.
The cells of the basal layer are small cubic, have high mitotic activity and perform the function of cambial cells.
2. From the nephroganotomy
1. Staining: hematoxylin, eosin
provide regeneration);
Stratified squamous non-keratinizing epithelium of the cornea
1. Staining: hematoxylin
2. From ectoderm
3. Consists of layers:
· basal layer
spinous layer
4. Lines the anterior ( oral cavity, pharynx, esophagus) and final section (anal rectum) digestive system, cornea. Mechanical protection.
Stratified squamous epithelium of the skin
1. Staining: hematoxylin
2. From ectoderm
3. Consists of layers:
· basal layer
spinous layer
granular layer
shiny layer
layer of horny scales
4. Epidermis of the skin. Defence from mechanical damage, radiation, bacterial and chemical exposure, differentiates the organism from the environment.
5. 
The basal layer contains stem cells for regeneration
Stratified transitional epithelium of the bladder mucosa
1. Staining: hematoxylin, eosin
2. From ectoderm
· basal layer
· intermediate layer
cover cells
4. Lines hollow organs, the wall of which is capable of strong stretching (pelvis, ureters, bladder). Protective.
5. The basal layer contains stem cells for regeneration
Coarse fiber bone. Total preparation of the gill arch of the fish cover
1. Coloring: no.
2. From mesenchyme.
3. Ossein fibers are arranged randomly and disorderly. Osteoblasts and osteocytes are located in the lacunae.
4. Present in cranial sutures, places of attachment of tendons to bones; in the embryonic period, first, in place of the cartilaginous model of the future bone, coarse-fibrous bone is formed, which then becomes fine-fibrous.
Transverse section of the decalcified diaphysis tubular bone(tibia)
1. Staining: thionin + picric acid, Schmorl method
2. From mesenchyme
3. 1) Periosteum (periosteum).
2) External general (general) plates - bone plates surround the bone along the entire perimeter, and between them are osteocytes.
3) Osteon layer. Osteon (Haversian system) is a system of 5-20 cylinders of bone plates, concentrically inserted into each other. A blood capillary runs through the center of the osteon. Osteocytes lie between the bone plates-cylinders in the lacunae. The spaces between adjacent osteons are filled with intercalary plates - these are the remains of the decaying old osteons that were here before these osteons.
4) Internal common (general) plates (similar to external ones).
5) Endooste - similar in structure to the periosteum.
4. Regeneration and growth of bone in thickness is carried out due to the periosteum and endosteum.
White adipose tissue
1. No coloring
2. See the rest above
Hyaline cartilage
1. 
Staining: hematoxylin, eosin
2. From mesenchyme
3. Cells – chondrocytes, chondroblasts, chondroclasts, semi-stem cells, stem cells. Chondrocytes are the main cells, oval-round in shape with basophilic cytoplasm, located in lacunae, forming isogenic groups
Intercellular substance - collagen fibers, elastic fibers and ground substance
Around the isogenic groups there is a clearly defined basophilic zone - the so-called territorial matrix
The weakly oxygenic areas between the territorial matrices are called the interterritorial matrix.
4. Covers all articular surfaces of bones, is contained in the sternal ends of the ribs, in the airways. Support-mechanical, protective.
5. Regeneration thanks to stem and semi-stem cells
Dog cerebellum
1. Color: AgNO 3
2. From the neural tube
3. Layers of bark:
Molecular (stellate and basket cells)
Ganglion (pyriform Purkinje cells)
Granular (granule cells, Golgi cells and spindle cells)
White matter: afferent and efferent fibers
4. Regulation of motor acts
Single-layer cuboidal epithelium of the renal tubules
1. Staining: hematoxylin, eosin
2. From the nephroganotomy
3. Consists of a single layer of sharply flattened cubic cells. When cut, the diameter (width) of the cells is equal to the height.
4. Found in the excretory ducts of the exocrine glands, in the convoluted renal tubules.
5. Regeneration occurs due to stem (cambial) cells, evenly scattered among other differentiated cells.
Single-layer multirow ciliated epithelium of the trachea
1. Staining: hematoxylin, eosin
2. From the endoderm of the epichordal plate
3. All cells are in contact with the basement membrane, but have different heights and therefore the nuclei are located on different levels, i.e. in several rows. Within this epithelium there are different types of cells:
Short and long intercalary cells (poorly differentiated and among them stem cells; provide regeneration);
Goblet cells - have the shape of a glass, do not perceive dyes well (white in the preparation), produce mucus;
- ciliated cells have ciliated cilia on the apical surface.
4. Lines the airways. Purification and humidification of passing air.
Single layer squamous epithelium represented in the body by endothelium and mesothelium. Mesothelium covers the serous membranes (leaves of the pleura, peritoneum and pericardium). Its cells - mesotheliocytes - lie in one layer on the basement membrane, they are flat, have a polygonal shape and uneven edges. Serous fluid is released and absorbed through the mesothelium, which facilitates the movement and sliding of organs (heart, lungs, abdominal organs). Endothelium lines the blood vessels, lymphatic vessels and heart. It is a layer of flat cells - endothelial cells, lying in one layer on the basement membrane. Only they come into contact with the blood and through them, in the blood capillaries, the exchange of substances between blood and tissues occurs.
Single layer cuboidal epithelium lines part of the renal tubules. It is a layer of cubic cells lying in one layer on the basement membrane. The epithelium of the renal tubules performs the function of reabsorption of a number of substances from primary urine into the blood.
Single layer prismatic epithelium It is a layer of prismatic (cylindrical) cells lying in one layer on the basement membrane. This epithelium lines inner surface stomach, intestines, gallbladder, a number of ducts of the liver and pancreas, some kidney tubules. In the single-layer prismatic epithelium lining the stomach, all cells are glandular producing mucus, which protects the stomach wall from damage and digestive action gastric juice. The intestine is lined with a single layer of prismatic bordered epithelium, which ensures the absorption of nutrients. To do this, numerous outgrowths are formed on the apical surface of its epithelial cells - microvilli, which together form a brush border.
Single-layer multirow (pseudostratified) epithelium lines the airways: nasal cavity, trachea, bronchi. This epithelium is ciliated, or flickering ( its eyelashes can move quickly in one plane - flicker). It consists of cells different sizes, the nuclei of which lie at different levels and form several rows - that’s why it is called multirow. It only seems that it is multi-layered (pseudo-layered). But it is single-layered, since all its cells are connected to the basement membrane. There are several types of cells in it:
A) ciliated(ciliated) cells; the movement of their cilia removes those trapped along with the air in Airways dust particles;
b) mucous membranes(goblet) cells secrete mucus onto the surface of the epithelium, performing a protective function;
V) endocrine, these cells release hormones into the blood vessels;
G) basal(short intercalary) cells are stem and cambial, capable of dividing and turning into ciliated, mucous and endocrine cells;
d) long insert, lie between the ciliated and goblet, performing supporting and supporting functions.
Stratified squamous non-keratinizing epithelium covers the outside of the cornea of the eye, lines the oral cavity, esophagus, and vagina. There are three layers in it:
A) basal the layer consists of prismatic-shaped epithelial cells located on the basement membrane. Among them there are stem and cambial cells capable of mitotic division (due to the newly formed cells, epithelial cells are replaced above the underlying layers of the epithelium);
b) spiny(intermediate) layer consists of cells of irregular polygonal shape, interconnected by desmosomes;
V) flat(surface) layer - finishing its life cycle, these cells die and fall off the surface of the epithelium.
Stratified squamous keratinizing epithelium(epidermis) covers the surface of the skin. The epidermis of the skin of the palms and soles has a significant thickness and there are 5 main layers:
A) basal the layer consists of prismatic shaped epithelial cells containing keratin intermediate filaments in the cytoplasm; there are also stem and cambial cells, after the division of which, some of the newly formed cells move to the overlying layers;
b) spiny layer - formed by polygonal-shaped cells that are firmly connected to each other by numerous desmosomes; the tonofilaments of these cells form bundles - tonofibrils, granules with lipids appear - keratinosomes;
V) grainy the layer consists of flattened cells, the cytoplasm of which contains grains of the protein filaggrin and keratolinin;
G) brilliant the layer is formed by flat cells that lack nuclei and organelles, and the cytoplasm is filled with the protein keratolinin;
d) horny the layer consists of postcellular structures - horny scales; they are filled with keratin (horny substance) and air bubbles; the outermost horny scales lose contact with each other and fall off the surface of the epithelium, and they are replaced by new cells from the basal layer.
Stratified transitional epithelium lines urinary tract(calyces and pelvis of the kidneys, ureters, bladder), which are subject to significant stretching when filled with urine. It distinguishes the following cell layers: a) basal; b) intermediate; c) superficial. When stretched, the cells of the superficial layer are flattened, and the cells of the intermediate layer are embedded between the basal ones; at the same time, the number of layers decreases.
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