Apical. Features of the structure of epithelial tissue. Characteristics of epithelial tissues. Different approaches to classification

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I am deeply convinced that this is not so, otherwise there would be no need to engage in politics, try to melt the "eternal pole

The article is dedicated to the poet, publicist, human rights activist Galansky Yuri Timofeevich and his social activities. The dominant place is occupied by the statements of Y. Galansky himself: fragments of his letters, articles, messages to the government and other authorities, as well as his poems.

before his arrest (it happened on January 19, 1967), his Dukhoborism resulted in an intention to create a "second pole<...>destructive potential is intertwined with the tendency of its concentration on hostile opposite poles

HISTOLOGICAL AND HISTO-AUTO-RADIOGRAPHIC STUDY OF THE SUB-COMMISSIONAL BODY IN NORMALITY, WITH CHANGES IN WATER EXCHANGE AND VOLUME OF CEREBROSPINAL FLUID ABSTRACT DIS. ... CANDIDATE FOR BIOLOGICAL SCIENCES

M .: MOSCOW VETERINARY ACADEMY

Based on the foregoing, we set ourselves the task: 1. Due to the fact that the subcommissural organ, as the morphological structure of the central nervous system, is little known in our country and the question of its structure is far from clear, to give a brief morphological description of the organ of domestic animals and person. 2. To study: a) the connection of Reisner's fiber or its fibrils with the surface of the subcommissural organ; b) Reisner fiber morphology; c) the reliability of secretion in the subcommissural body; d) communication of the organ with cerebrospinal fluid; e) connection of the organ with water exchange.

pole.<...>At the apical pole of the cells, and especially where there are crypts, homopositive granularity is found.<...>In some cases, you can see the rupture of the apical pole of the goblet cell and the release of the cell contents.<...>Towards the apical pole of the cells, the homogeneous coloration is retained, but against its background clearly<...>The apical pole dome-shapedly rises above the free surface of the organ, and the basal part of the cell

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The ultrastructure of nephrocytes of proximal and distal convoluted tubules, podocytes, mesangiocytes and macrophages of interstitial connective tissue of rat kidneys after a single intravenous injection of nanosized magnetite particles modified with chitosan (magnetic nanospheres) or lipids (magnetoliposomes) was studied. Using transmission electron microscopy, the ultrastructural features of the absorption of nanosized particles of magnetite have been established, and the shape, size and number of vesicles containing nanoparticles in nephrocytes of convoluted tubules and macrophages of rat kidneys after administration of suspensions of nanospheres and magnetoliposomes have been described.

1.2 μm) with electron-dense structures 90-100 nm in size were found on the basal (Fig. 2, a) and apical<...>the poles of the nephrocytes of the proximal and distal convoluted tubules.<...>During the experiment, vesicles in nephrocytes moved from the basal cell to the apical pole.<...>(2) pole.<...>The movement of vesicles in the nephrocytes from the basal pole to the apical pole indicates the transfer of the LFM.

The article describes the micromorphology and histochemistry of the cells of the mucous membrane of the caudal part of the funnel, protein and shell parts of the oviduct of chickens during oviposition, and analyzes their participation in egg formation. All cells of the mucous membrane of the oviduct can be divided into three groups: 1. cells of the integumentary epithelium; 2. epithelial cells of the lamina propria glands; 3. connective tissue cells. The integumentary epithelium of the folds of the oviduct funnel is represented by two types of cells - ciliate and goblet. Epithelial cells of the tubular glands of the caudal part of the funnel are cubic or columnar. The structure of the integumentary epithelium of the protein section includes three types of cells - ciliate, goblet and protein secreting. In the protein part of the oviduct, three generations of glands were found, the epithelial cells of which differ from each other morphometrically. The integumentary epithelium of the shell section is single-layer, two-row, columnar ciliated, represented by ciliate and goblet cells. Epithelial cells of the tubular glands of the shell section are columnar. In the loose connective tissue of the mucous membrane of the oviduct, there are fibroblasts, histiocytes, tissue basophils, plasma cells, lymphocytes, and in the shell section - eosinophilic macrophages.

third, ciliate, goblet and protein-secreting at the apical end.<...>pole or lie centrally, the nuclei of the goblet cells are always located eccentrically, closer to the basal<...>pole of cells.<...>The apical cytoplasm is weakly basophilic, foamy.<...>The cytoplasm of cells near the nuclei is intensely basophilic, and its apical part is foamy, weakly basophilic

The aim of the work was to study the dynamics of the content of different forms of lymphocytes in the white pulp of the spleen of chickens during ontogenesis. The studies were carried out on 20 chickens of the Lohmann-Brown cross during critical periods: adaptation (3–14 days), juvenile (30–45 days), morphofunctional maturity (8–18 months). It was found that at the stage of adaptation and in the juvenile period, large lymphocytes are detected in all zones of lymphoid nodules, however, in the juvenile period their content decreases by 1.6 times, at the stage of morphofunctional maturity - by 2.4 times. At the stage of morphofunctional maturity in all zones, an increase in the number of small lymphocytes by 2.9 times compared with that in the periods of adaptation and juvenile is revealed. The proportion of average lymphocytes with the age of the bird changes insignificantly - at the stage of morphological and functional maturity, it increases by 1.2 times.

<...>

Histology of the digestive system organs textbook. manual for students studying in the specialty "Dentistry"

The textbook is based on the extended content of lectures on the specialized sections of the course of private histology for dental students, as well as detailed methodological recommendations for laboratory and practical exercises in the relevant sections with a description of drugs, diagrams and micrographs. Special attention given to the sections on the structure and development of teeth.

cells (into the former apical pole, which has become functionally basal); cells acquire a highly prismatic<...>At this pole, an outgrowth (Toms outgrowth) is formed.<...>and basal poles.<...>Parietal cell functions: through the apical pole, parietal cells secrete hydrogen and chlorine ions<...>poles (fig. 37).

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In order to study the histological structure of the lacrimal gland, material was obtained from 10 rabbits of 1.5 years of age of the Soviet chinchilla breed.

In many cells, an oxyphilic homogeneous secret in the form of a half moon accumulates at the apical pole.<...>Often this secret is found in the cavity of the secretory section, near the apical pole of cells or in

The aim of the study was to study the effect of liver damage of mesenchymal genesis in the mother on spermatogenesis in offspring. Wistar rats were taken as the object of the study. The animals were divided into 2 groups: control (53 animals from 15 litters) and experimental (51 animals from 13 litters). The experimental animals were divided into 5 age subgroups: 1-, 15-, 30-, 45- and 70-day-old. We used morphological, morphometric and statistical research methods. To assess the activity of spermatogenesis, various criteria were used: the diameter of the seminiferous convoluted tubules, the proportion of tubules with desquamated epithelium, the number of sustentocytes, spermatogonia, spermatocytes, spermatids and spermatozoa, the total content of spermatogenic cells and the number of giant spermatogenic cells, including those with destroyed nuclei.

Cytology, histology, embryology. Part 1 methodical instructions and a workbook for laboratory and practical exercises

RIC SGSKhA

The methodological instructions provide information on the methods of histological examination, structural features of cells of animal origin. Methods of cell division, violations of their normal division, stages of development of multicellular organisms in embryogenesis, structural features are considered. different types fabrics. To check the degree of assimilation of tasks, control questions were drawn up. In addition, questions for the colloquium are presented at the end of each section.

Under a low microscope magnification, small blastomeres are visible at the apical pole, at the vegetative pole<...>Sketch (Fig. 17) and mark: 1 - blastomeres of the apical pole, 2 - blastomeres of the vegetative pole<...>At the apical pole, they have a delicate border of pale pink color - cilia that can be seen<...>apical pole.<...>pole of one cell; 4 - basal pole of the same cell; 5 - cell nucleus; 6 - basement membrane; 7 -

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In order to simulate ischemia, the anterior descending branch of the left coronary artery was ligated in 48 rabbits. After 5 days, the animals of the experimental group were injected intramyocardially with a suspension of the Alloplant biomaterial (BMA), and in the control group, physiological saline was used. At various times after the operation, histological, electron microscopic and immunohistochemical studies were performed. In rabbits of the control group in the ischemic area, signs of pronounced inflammatory response, the outcome of which was the formation of dense avascular connective tissue with subsequent degeneration into adipose tissue. In rabbits in the experimental series, implanted BMA particles initiated the migration of monocytes – macrophages and their phenotypic maturation.

The article presents the results of a morphological study of the uterus obtained after hysterectomy from 60 patients with diffuse adenomyosis of the II-III degree, accompanied by a pronounced syndrome of chronic pelvic pain. The general morphological assessment of the sections of the uterus was carried out by staining with hematoxylin and eosin. To assess the nature of intercellular cooperation, various cell lines were visualized by immunohistochemistry. To study the kinetics of cells, cell proliferation and apoptosis were assessed using monoclonal antibodies to Ki-67 and p53, respectively. Estrogen sensitivity was determined using monoclonal antibodies to estrogen receptors. It is concluded that in adenomyosis, a violation of epithelio-mesenchymal relations is recorded, which determine the violation of the morphogenesis of the branching of the uterine glands, which is accompanied by an increase in the proliferation of epithelial cells against the background of a high sensitivity of epithelial and stromal cells to estrogens

immaturity, the manifestations of which were a high nuclear-cytoplasmic ratio and the absence of a developed apical<...>poles.<...>the formation of a pseudo-multi-row pattern (due to the close arrangement of nuclei in the absence of a pronounced apical<...>poles of cells of the uterine glands).

A morphological and ultrastructural study of the kidneys of rats with experimental oxalate nephrolithiasis was carried out. The features of the development of stress of the endoplasmic reticulum in nephrolithiasis and during the use of β-tocopherol were studied. Signs of endoplasmic reticulum stress with activation of the proapoptotic branch and damage to the cell lining of the nephron tubules and collecting ducts were revealed. Shown are ultrastructural changes in organelles, nuclei and cell membranes of epithelial cells. The relationship between the processes of stress in the endoplasmic reticulum and oxidative damage that develops in the early stages of lithogenesis has been established.

Ultrastructural changes mainly affected the apical parts of epitheliocytes, basal<...>the poles of the cells suffered to a lesser extent.<...>More pronounced changes found in the apical poles of epitheliocytes, which can be explained by the process

Physiology

The textbook contains test items for preparation for the final certification in human and animal physiology for the following didactic units: Digestion, Respiration, Metabolism and energy, Heat production and heat regulation, Immunology, Excretion, Higher nervous activity, Central nervous system, Physiology of excitable tissues, Adaptation; on plant physiology according to the following didactic units: Plant cell physiology, Water regime, Photosynthesis, Respiration, Mineral nutrition, Plant growth and development, Plant resistance to adverse conditions. - Elista: Kalmyk University Publishing House, 2013. - 50 p.

the pole of the cell and the exit of the secretory material from the cell. ten.<...>In the center there is an elongated nucleus, at the poles of the GRES, the Golgi complex and ribosomes.<...>The difference in the polarization of the basal and apical membranes is 2-3 mV. which creates significant<...>the pole of the cell and the exit of the secretory material from the cell. 4.<...>Apical meristem of shoots 2. Green leaf 3. Growth point 4.

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Cytology, histology and embryology: Study guide. Part 2

The presented training manual includes methodological material on the topics of private histology, which is presented in accordance with the requirements of the third generation FSES HPE, curriculum, working curriculum for the discipline "Cytology, histology and embryology". The educational-methodical manual is intended for students of higher educational institutions studying in the direction of training (specialty) 111801 “Veterinary medicine” (qualification (degree) “specialist”). For successful implementation by students independent work the manual provides questions, tests and situational tasks for self-examination, allowing them to gain good knowledge and a more complete and complex understanding of the histophysiology of organs and tissues of animals.

The apical surface of the columnar limb epithelial cell of the small intestine 1.<...>The proximal convoluted tubule is formed by: 1) nephrocytes that do not have a brush on the apical surface<...>In the basal pole of the cells, folding of the cytolemma is found, surrounded on the side of the cytoplasm by a large<...>There are microvilli at the apical pole.<...>There is striation at the basal pole of the cells. There is no brush border at the apical pole.

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The aim of the research was to establish the location and number of endocrine cells in the intestines of adult geese. The studies were carried out on domestic geese (Anser anser) of a large gray breed of 1.5 years of age. Material for histochemical studies was taken from 5 individuals, 3 pieces each, from the middle of the proximal, middle and distal third of the duodenum, jejunum, ileum, cecum and rectum. Paraffin histosections to identify argyrophilic apudocytes were stained according to Grimelius, argentafin ones - according to Masson-Gamperl. The number of endocrinocytes was determined using an ocular morphometric grid with subsequent recalculation per 1 mm2 of the cross-sectional area of the intestinal mucosa. The endocrine apparatus of the intestine is represented by apudocytes, singly located among the enterocytes of the epithelial layer of the mucous membrane. Apudocytes were clearly visible due to secretory granules located at the basal pole. In the duodenum, endocrinocytes are localized only in the lower third of the crypts, in the jejunum, ileum - at their entire depth, in the blind and rectum - also in the epithelium of the villi. The number of argyrophilic and argentaphenic endocrine cells gradually increases in the direction from the duodenum to the rectum, with the maximum content in the middle part of the ileum (56.25 ± 2.91 and 25.45 ± 2.60) and in the proximal part of the rectum (128.5 ± 5.62 and 79.19 ± 3.18). The relative content of visible Argentafin cells among the entire population of endocrinocytes was highest in the proximal third of the jejunum and middle third of the rectum, 81.93 and 82.99%, respectively, and the lowest in the initial part of the duodenum - 40.89%, as well as in the ileum and cecums 40.24 - 52.00%. The maximum and minimum values of the number of apudocytes do not always correspond to the anatomical boundaries of the intestines.

Apudocytes were clearly visible due to secretory granules located at the basal pole.<...>singly on the basement membrane, have an oval, rounded, sometimes elongated shape, a wider basal pole<...>When impregnated with silver nitrate, the basal pole of endocrine cells is clearly revealed, since<...>the largest number of granules is concentrated in it; the apical pole is not visible in all cells.

The aim of this work is a histological study of the anterior corneal epithelium (PER) of an adult male African ostrich Struthio camelus Linnaeus, 1758 (Struthioniformes). The total thickness of the PER is 48.5 ± 1.1 μm. The geometry of epithelial cells was investigated. Basal cells (height - 21.4 ± 1.8 μm, width - 5.9 ± 0.4 μm, configuration index - 3.8 ± 0.5) have a columnar shape. Intermediate cells (height - 6.2 ± 0.3 microns, width - 12.0 ± 0.8 microns, configuration index - 0.54 ± 0.06) are predominantly ellipsoidal. Surface cells (height - 3.8 ± 0.3 microns, width - 22.4 ± 1.7 microns, configuration index - 0.180 ± 0.020) have a flat shape. The index of flattening of the surface layer epithelial cells is 5.8 ± 0.5. A negative correlation was revealed (r ± mr = –0.72 ± 0.13) between the height and width of epithelial cells

The basal layer consists of cells, mainly with clavate thickened apical parts.<...>of the overlying layers, while the rounded nuclei are located mainly either in the center, or are displaced towards the apical<...>pole.

MORPHOGENESIS OF EXTRAORDINARY ROOTS IN GREEN CUTTINGS OF TWO-LONGED ABSTRACT DIS. ... DOCTORS OF BIOLOGICAL SCIENCES

The purpose and objectives of the research. The sequence of formation of cladogenic roots can be considered at the tissue level as a restructuring of the stem tissue in the root tissue and at the organ level - as a restructuring of a part of the shoot axis into the root axis. The regular subordination of the stages through which the transformations of one axis into another pass, probably, in the main outlines, repeats the real paths of phylogenesis of adventitious roots, including evolutionary acquisitions during the development of rhizophytes.

growing primordium, and in their former place are cells of the mature parenchyma of the proximal pole<...>With the volumetric growth of the apical meristem, the number of cells required for the action of<...>The apical meristem of the adventitious root is usually of this type (according to G. Gutenberg, 1960).<...>The body of the root exists in this complex as a result of histogenesis of the apical meristem, therefore, not the root<...>Under the conditions of the stem-root unity of the axis, all evolutionary changes in the constitution of the apical meristem

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Extended lecture notes on cytology, histology and embryology

FSBEI HPE Izhevsk State Agricultural Academy

The edition contains an extended lecture notes on cytology, histology and embryology.

) yolk, and at the other pole (animal) nucleus and organelles.<...>Incomplete crushing when crushing occurs only at the animal pole, the vegetative pole is overloaded with yolk<...>On the apical surface, they may have ciliated cilia.<...>Thyroglobulin accumulates in the lamellar complex, then through the apical pole of the cells is secreted into<...>Mitochondria have microvilli on the apical surface.

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136 infertile men were examined (mean age - 34.33 ± 6.49 years; duration of infertility - 3.72 ± 2.94 years. the level of lysozyme in the seminal fluid by the intensity of lysis of the Micrococcus lysodeicticus suspension, the level of fructose by the color reaction of HCl with resorcinol, the level of total protein.Comparison of 2 independent groups by quantitative characteristics was carried out by a nonparametric method using the Mann-Whitney test, the differences were considered statistically significant at P

Studied the histological structure of the harder gland (GG) of chickens at the age of 1, 14 and 35 days (10 heads per group). It was revealed that GJ has a lobular structure, lobules - of a cylindrical shape. In each lobule, one can distinguish the central duct (CP), the lymphoid part extending into the cavity of the CP in the form of folds, and the glandular part located along the periphery. CP epithelium is low columnar. In some cells, there is an accumulation of homogeneous weakly basophilic secretion at the apical pole. The lymphoid part of the GJ is formed by lymphocytes with a large nucleus. The glandular part consists of tubular glands lined with high columnar epithelium. The cytoplasm of epithelial cells is vacuolated; the core is oval, located in the basal part. In the lumen of the glands there is a foamy, less often a homogeneous weakly basophilic secret.

In some cells, there is an accumulation of homogeneous weakly basophilic secretion at the apical pole.

Erectile dysfunction (ED) is seen as a precursor and concomitant ischemic disease heart (ischemic heart disease). Purpose of the study: to compare morphological changes in the cavernous tissue of the penis with changes in the heart muscle in men who died from coronary artery disease. Fragments of the cavernous tissue of the penis and myocardium were studied from 45 men who died from various pathologies. Microscopic examination (staining of histological preparations with hematoxylin-eosin) and morphometry were used. The age of men ranged from 20 to 86 years, (on average - 51.5 years). 45 micropreparations of cavernous tissue and 45 of myocardium were made. Based on the causes of death, all men were divided into groups: 23 (51.1%) - died from coronary artery disease, 22 (48.9%) - died from other causes.

In some cells, there is an accumulation of homogeneous weakly basophilic secretion at the apical pole.

Molecular genetic aspects of the formation of the retina are considered. This part of the eyes is formed from an independent source of the neural epithelium of the anterior part of the brain as a result of the sequential formation of the eye field, protrusion of the eye vesicles, and the formation of the optic cup. It consists of two layers: the multilayer retina itself and the layer adjacent to it pigment epithelium eyes. The structure and function of photoreceptors and retinal pigment epithelium are considered. Their interaction in the process of light perception is shown and the process of phototransduction is described, i.e. converting visual information in photoreceptors into electrical impulses with their subsequent transfer to brain analyzers.

Several factors have been identified that are involved in the establishment and maintenance of apical-basal polarity.<...>Mutations in genes for apical-basal polarity have been associated with various retinopathies in humans (Richard<...>axis, although rapid migration to the apical side is mainly mediated by actomyosin activity.<...>In contrast, the prolonged presence of the nucleus in the apical domain increases the exposure time of the transmission<...>A large number of microvilli and melanosomes are present at the apical pole of pigment epithelial cells

MORPHOLOGY OF BIRD ORGANS AND TISSUES IN INFECTION WITH ASCARIDIA GALLI AND ESCHERICHIA COLI ABSTRACT DIS. ... CANDIDATE OF VETERINARY SCIENCES

M .: MOSCOW STATE UNIVERSITY OF APPLIED BIOTECHNOLOGY

The aim of our research was to study the morphology of organs and tissues of poultry with simultaneous infection with Ascaridia galli and Escherichia coli.

section of the intestine during electron microscopic examination had a bulky, collapsed shape, apical<...>In the middle part of the intestine of ascaridia, these enzymes were detected in the apical poles of epithelial cells.<...>LLC "Agency Book-Service" The villi of the intestinal mucosa had a collapsed shape; apical

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Ultrastructural studies of the non-lactating mammary gland of Saanen goats have been carried out. Morphofunctional structural components of mammary gland cells in Saanen goats in an inactive physiological state of the udder. The material for histological and electron microscopic studies was small (2-4 mm³) samples of the mammary gland of a goat. Pieces are taken from deep areas of the organ parenchyma. The material was collected and fixed immediately after the slaughter of the animals. Selected samples were fixed in a 2.5% solution of glutaraldehyde in 0.1M phosphate buffer for 1 hour at room temperature, after which they were washed in 3 changes of phosphate buffer. Then, the pieces were post-fixed in a 1% solution of osmium tetroxide in the same buffer at the same temperature for 1 hour. After fixation, the samples were dehydrated in a series of ethanol solutions of increasing concentration, impregnated with acetone and enclosed in Epon epoxy resin. For the first time, our ultrastructural studies have shown that the secretory epithelium of the milk alveoli in the parenchyma of the non-lactating mammary gland of Saanen goats is mainly (by 75-80% of the cellular composition) formed by prismatic lactocytes, the nuclei of which are located in 2-3 rows. It was found that the apical surface of lactocytes forms small microvilli with a height of about 0.5 μm, they indicate the reabsorption capacity of the epithelium, and in addition to mitochondria, cisterns of the rough endoplasmic reticulum were found in the cytoplasm, which on ultrathin sections is represented by membrane tubules and cisterns interconnected with each other, as well as elements of the Golgi apparatus. Electron microscopy showed that the Golgi apparatus consists of clusters of flat cisterns, on average about five to seven packets, the so-called dictyosomes. The morphology of cells in the parenchyma of the non-lactating mammary gland of Saanen goats indicates that they are in a state of relative physiological rest.

It was found that the apical surface of lactocytes forms small microvilli with a height of about 0.5<...>It was found that the apical surface of lactocytes forms small microvilli with a height of about 0.5<...>One pole of the filaments is attached to the apex of the microvillus, the other pole is tied into a beam of spectrino-like<...>In the apical region of the cytoplasm, an electron-dense center of organization of microtubules is revealed, which<...>Both of these types of cells do not go out to the apical surface of the epithelial layer, being located in the basal

Zoology of invertebrates. Part 1 course of lectures

Rostov n / a .: SFedU Publishing House

Zoology is devoted to the study of the structure, life, development of animals, their relationship with the environment, their origin and evolution. Zoology, along with botany, is the central subject of training for biologists. The proposed manual includes material from lectures on invertebrate zoology, which are read to 1st year students of the Faculty of Biology and Soil Science of the Southern Federal University. The manual provides characteristics of all types and major classes of invertebrates (the first part of the manual contains characteristics from protozoa to annelids, inclusive). The organizational and methodological section of the proposed manual contains instructions for independent work of students on a rating basis.

Epithelial cells have two poles - basal, facing inward of the body, and apical, facing<...>poles.<...>Osculum forms in the apical part of the body.<...>aboral pole.<...>At one end of the body - the oral pole - the mouth is placed, at the opposite - the aboral pole - the specific

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IMMUNOBIOLOGICAL REGULARITIES AND IMPROVEMENT OF THE TECHNOLOGY OF REPRODUCTION OF AGRICULTURAL ANIMALS ABSTRACT DIS. ... DOCTORS OF BIOLOGICAL SCIENCES

ALL-RUSSIAN RESEARCH INSTITUTE OF ANIMAL BREEDING AND GENETICS (LENINGRAD-PUSHKIN)

The aim of our research was to find out what part of animals after unsuccessful inseminations falls on females with no fertilization, and what part on animals with prenatal losses, to develop methods to reduce these losses and increase the efficiency of artificial insemination.

the protoplasm of the cells of the glandular epithelium becomes denser, point granules appear in it, the nuclei move to the apical<...>pole, the process of phagocytosis is clearly expressed.<...>protoplasm, acquire a goblet, cylindrical and highly cylindrical shape, with cilia on the apical<...>pole, with active signs of secretion.

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"MORPHOLOGY OF THE PANCREAS OF CHICKENS OF THE BREED" LEGGORN "" IN THE AGE ASPECT (ANATOMO-HISTOLOGO-ELECTRONOMICROSCOPIC RESEARCH) "ABSTRACT DIS. ... CANDIDATE FOR BIOLOGICAL SCIENCES

M .: MOSCOW ORDER OF LENIN AND THE ORDER OF LABOR RED BANNER AGRICULTURAL ACADEMY NAMED AFTER K. A. TIMIRYAZEV

Proceeding from the fact that in the educational and scientific literature there is very incomplete information about the anatomical, histological and electron microscopic structure, about the variations in the anatomy of the gland and the topography of the insular apparatus in different parts of it in adult chickens, we set ourselves the first task to study from these points of view of the indicated gland of adult Leghorn chickens.

The apical ends are connected by means of end plates.<...>Inside the vacuole there is a substance of average electron density, which is pressed to one of the poles<...>At the apical pole there are microvilli with numerous pnnocytic vesicles.<...>The nucleus is displaced closer to the basal pole.<...>These are 2-3 rather long tubules lying parallel to each other and to the plasmalemma, and the apical part

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Phyllotaxis: A Systemic Study in Plant Morphogenesis

Moscow: Institute for Computer Research

Phyllotaxis, that is, the study of the patterns formed by leaves and other organs, raises one of the deepest questions associated with plant morphogenesis. The question itself is formulated as follows: what principles of biological organization underlie the formation of these dynamic geometric systems? The invariable presence of Fibonacci numbers in such systems has fascinated more than one generation of mathematicians and botanists. In this book, for the first time ever, many aspects of phyllotaxis are presented as a whole. The combined concept of phyllotaxis, adopted by the author of this book, is based on experimental, anatomical, psychological and paleontological observations and findings, as well as on the study of the cellular structure of living organisms. The book can serve as a basis for a formal analysis of botanical data, with the main emphasis on the fact that phyllotaxis paradigms play a very important role in the study of other structures, such as crystals and proteins.

This center is the common pole of all spirals, as well as the place where all primordia are laid.<...>On each copy we will draw a family of x spirals going out from one pole and passing all the points<...>Thus, it can be expected that the relative apical radius L, the relative apical area<...>apical volume, apparently defined as 1 / (3 lnR).<...>What are the apical dome, meristem, and primordium?

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Lewin 's Cells

M .: Laboratory of Knowledge

The translation of the second English-language edition includes the latest advances in cell biology. The structure, organization, growth of cells, regulation of intracellular processes, cell motility, interaction between cells are described. Eukaryotic cells are examined in detail. Each chapter is written by leading scholars in these fields. The structure of the book has been carefully formed, the terminology has been verified. Much importance in the book is attached to the discussion of the molecular basis of human diseases.

spindle Spindle pole Spindle pole Spindle pole Split groove Star Star Spindle equator<...>tubulin KINETOCHORA THREAD Exit Exit Exit Exit POLE Pole movement POLES Depolymerization of PAC-MAN<...>This is believed to result in contractions that reshape the apical pole of the epithelial cells.<...>In what follows, we will see how special thickening of the cell walls of the Apical shoot meristem Apical<...>The apical meristem is in the center.

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INFLUENCE OF HETROCARPY BUFF. DEVELOPMENT AND PRODUCTIVITY OF THE MEDICINAL CALENDULA ABSTRACT DIS. ... CANDIDATE FOR BIOLOGICAL SCIENCES

INSTITUTE OF PHYSIOLOGY, GENETICS AND BIOENGINEERING RASTE

The aim of this work was to study the patterns of formation of heterocarpic seeds and the effect of heterocarp on the growth, development and productivity of Calendula officinalis L.

Large differences were found in heterocarpic seeds in the degree of development of the apical bud.<...>the bud, although enlarged in comparison with the apical bud of ring-shaped seeds, is also<...>Even before the seeds germinate during the swelling period, the apical bud can be clearly distinguished in the seed.<...>synergids are large pear-shaped cells that are located at the micropilar pole<...>The central cell occupies most of the embryo sac and extends from its micropilar pole

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Anatomy and morphology of lab plants. workshop

Sib. Feder. un-t

The dictyosome has a regeneration pole, on which the formation of<...>Book-Service ”cisterns are made of EPR membranes, and the secretory pole, where the Golgi vesicles are detached.<...>Get acquainted with the structure of the shoot apical meristem. 2.<...>Sketch the structure of the shoot apical meristem.<...>Three cells located at the halasal pole are called antipodes.

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Atlas of echinoderms and ascidians of the Far Eastern seas of Russia

Russian Island

The atlas is dedicated to echinoderms and ascidians living in the Far Eastern waters of Russia. A description of 58 species of these marine aquatic organisms is given, which makes it possible to use the book as a reference during the analysis of catches when conducting accounting scientific surveys.

The apical area is wide (more than 20% of the shell diameter).<...>The mouth and anus are located centrally at opposite poles.<...>The anal opening is located in the center of the apical field.<...>The apical area on the dorsal side is slightly shifted forward.<...>Apical field (apical pole) - upper (aboral) part sea urchin bearing in the center of the anal

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EMBRYOLOGY OF WHEAT-RYE AMPHIDIPLOIDS ABSTRACT DIS. ... CANDIDATE FOR BIOLOGICAL SCIENCES

M.: MOSCOW ORDER OF LENIN AND ORDER OF LABOR RED BANNER STATE UNIVERSITY NAMED AFTER M.V. LOMONOSOV

The purpose and objectives of the research. This work was aimed at studying the processes of sporogenesis, fertilization, embryogenesis and the formation of endosperm in wheat-rye amphidiploids (Triticale).

the other halves of the univalents, without splitting, are located along the spindle, while the bivalents are at the poles<...>Sometimes most or all of them are humiliated, they manage to catch up to the poles in time, and then the telophase of the I division<...>In anaphase and telophase, such scattered chromosomes are partially pulled up to the poles, partially vacuolated<...>tubes into the embryonic sac, in our observations one sperm is localized in the nasal part, and the other in the apical<...>In the apical widened part of the embryo, a cleoptile roll, which forms a depression, stands out from the side.

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No.3 [Ontogenesis, 2017]

Interestingly, the activated form of PKCδ in MII oocytes, like GAP-43, is specifically associated with the poles<...>and the basal poles (Fig. 3a).<...>and basal poles, shoot and root apexes both in embryoids and in embryos.<...>In this and the following figures, the front pole is on the left, unless otherwise indicated.<...>At the posterior pole of the regenerative blastema, directly under the integumentary epithelium, phalloidin reveals

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Botany with the basics of plant ecology. Part I textbook. manual for students enrolled in higher programs. education in the areas of training 06.03.01 Biology and 06.03.02 Soil Science

The study guide is dedicated to botany and plant ecology, written in accordance with the requirements of the state educational standard and curriculum discipline. It is intended for classroom and independent work of students of biological specialties full-time education. The textbook consists of sections that include theoretical material, a methodology for conducting environmental excursions and observations in nature, a guide to carrying out research work, self-study control questions, which allow you to expand your knowledge of the theoretical course and acquire the skills of experimental research.

One chromatid from a pair comes to the poles - these are daughter chromosomes.<...>The amount of genetic information at each pole is now (2n 2c).<...>In the anaphase of the first meiotic division, chromosomes, not chromatids, diverge to the poles of the cell.<...>The threads of the achromatin spindle go to the poles. A metaphase plate is formed. Anaphase II.<...>It is located under the cap and is represented by the cells of the apical meristem. Its length is about 1 mm.

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Botany Terminological Dictionary

FSBEI HPE Orenburg State Agrarian University

This terminological dictionary was compiled at the Department of Botany and Plant Physiology of the Orenburg State agrarian university and includes basic botanical concepts covering all sections of the discipline "Botany": cytology, histology, organography, taxonomy, geography and plant ecology. Designed for use by full-time students and extramural forms training in the areas of training 110400.62 - Agronomy, 250100.62 - Forestry, 110900.62 - Technology of production and processing of agricultural products to increase the level of assimilation and consolidation of knowledge, increase the intensity of the educational process during classroom lessons and summer training practice, when preparing reports, messages, abstracts.

Amphitrichs (bipolar polytrichs) are bacteria that have a bundle of flagella at each pole.<...>Copyright OJSC "CDB" BIBCOM "& LLC" Agency Book-Service "7 Apex, apical meristem, apical<...>Apical (from Latin apex - apex) - apical, located closer to the morphologically upper end<...>Apical meristem - a meristem localized at the poles of the embryo - the tip of the root and the kidney, forming<...>Protoderm - the outer layer of cells of the apical meristem of the shoot or root, which divide anticlinal

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Biology of plant growth and development [monograph]

Kalmyk State University

The monograph attempts to study the development of the structure of a flowering plant from seed to seed. Particular attention is paid to the activity of the educational tissue, which ultimately leads to the establishment of permanent tissues, organs and the body as a whole. The general patterns of morphological and anatomical changes in a plant organism in ontogenesis are described. On specific examples, the dynamics of growth of annual shoot and its individual lateral photosynthetic organs is considered, a mathematical model approximating their growth is selected, and a correlation between the characteristics of the shoot is established. The structural characteristics of the age periods of ontogenesis are given.

Embryo roots, bud with leaf buds are formed at two opposite poles<...>In the developing seedling, the initiation and development of the conducting system begins from two opposite poles<...>Each of the three histogens of the apical meristem has its own initials.<...>Already in the embryo of seeds, two future poles of nutrition are isolated, connected by an embryonic stalk.<...>H + enters the apical cells, exits the basal cells.

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Laboratory studies in histology. In 2 hours Part 1 study. allowance

Buryat State University

Each topic of the manual contains modern theoretical information, sets out the goals, objectives, necessary baseline knowledge, methods of studying histological structures under a light microscope, control questions, tasks, list of references.

In the dictyosome, the proximal (cis-pole) section, facing the nucleus, and the distal (trans-pole<...>Their main function is the formation of poles during the period of mitotic cell division.<...> <...> <...>Microvilli and cilia can be located on the apical surface.Closing (tight) contacts that unite

ASTRAKHAN STATE UNIVERSITY

The aim of this work was the ecological assessment of the genotoxic effect of atmospheric air pollution in various districts of the city of Astrakhan and the region by the method of micronucleus testing. To achieve this goal, the following tasks were solved: 1. To determine the frequency of occurrence of micronuclei in the cells of the apical meristem of black poplar buds from different territories of the city of Astrakhan and the region, depending on the level of anthropogenic load; 2. To determine the main types of micronuclei, the frequency of their occurrence, the nature of violations of the mitosis process in the apexes of the shoots under the influence of the total action of undifferentiated factors of air pollution; 3. To study the frequency of occurrence of micronuclei in cells of apical meristems in different seasons of the year; 4. Use a micronucleus test for environmental assessment of the genotoxic effect of atmospheric air pollution in the city of Astrakhan and the region for areas with different anthropogenic load.

Establish the frequency of occurrence of micronuclei in the cells of the apical meristem of the buds of black poplar of different<...>To study the frequency of occurrence of micronuclei in cells of apical meristems in different seasons of the year; 4.<...>Types of micronuclei in cells of the apical meristem of shoots in the black field: a / micronucleus of "standard"<...>Alov, 1972; Brodsky, Uryvaeva, 1981) as follows: lagging chromosomes when they diverge to the poles<...>Immediately before the start of the micronucleus analysis, the isolated apical meristem of the cone

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Cytology and histology textbook. allowance

The textbook provides data on the microscopic and submicroscopic structure of cells, tissues and organs in their normal, intact state, contains descriptions of drugs that should be considered by students in practical classes. The manual is supplied with a large number of drawings, diagrams and micrographs, including electronic ones, taking into account modern cytological data.

Some of the microtubules go from pole to pole (from centriole to centriole).<...>Others stretch from the pole to the centromere (constriction) of one of the chromosomes.<...>part of the glandular cell, and microapocrine, when the apical parts of the microvilli are separated.

Medicine of the Far East

The proposed teaching aid is written in accordance with the current program and the latest data on histology, embryology and cytology for students of 1-2 courses of medical universities in the following specialties: 060101 General Medicine, 060103 Pediatrics, 060105 Medical and Preventive Business, 060201 Dentistry. The main task of the manual is to give students in a concise form the necessary information for successful work during laboratory studies and during individual work at the department in order to develop their skills for independent study of the microstructure of tissues and identify their main morphological features.

Numerous cilia are visible on the apical part of the cells. Task 5.<...>Epithelial cells are polar, with apical and basal poles.<...>; opposite pole

It was found that adaptive changes in the structure of thyrocytes in rabbits under iodine deficiency were detected earlier than hormonal imbalance was detected. The cell nucleus is rounded-oval with a winding contour. Euchromatin mainly occupies the trunk position; condensed regions of heterochromatin are found closer to the karyolemma. The number, size and position of nucleoli are variable.

Lysosomes are numerous, located in the apical part of the cell, have a polygonal shape, high electronic<...>Mitochondria are single, significantly enlarged, displaced to the basal pole of the cell, cristae are expressed, matrix<...>Thyrocytes are somewhat flattened, an increase in the number of pseudopodia is noted on the apical surface, which is inversely correlatedparts

Purpose of the study: to determine clear ultrasound signs of kidney cancer Material and methods. During preventive examinations in the period 2013–2015. 8 patients with asymptomatic kidney cancer were identified. Results. Renal cell carcinoma of the kidney. Ultrasound examination: the kidney is often enlarged in size, the contours are uneven, indistinct. In the projection of the lower or upper pole, a volumetric formation is visualized, possibly containing both tissue and fluid components in its structure.

In the projection of the lower or upper pole, a volumetric formation is visualized, possibly containing in its<...>longitudinal strain (HPSS) up to −13%, circumferential strain (CVS) on the basal (−8%), average (−11%) and apical<...>GPSS were approaching normal values(-19%), CVR indicators on the basal (-18%), average (-26%) and apical<...>biomechanics of heart twisting in the first case worsened - unidirectional rotation of the basal and apical

On 64 outbred white rats weighing 180–220 g, exposed to natural gas at a concentration of 3 mg / m3 in hydrogen sulfide for 4 hours, 5 days a week for 4 months, the vessels of the microvasculature in the wall of the small intestine were studied. We used standard histological and histochemical staining methods: hematoxylin-eosin, according to Van Gieson, strong green, SHIK reaction. To study vascular permeability, a 0.3% solution of acridine orange was injected into the vascular bed, followed by luminescence microscopy of the vessels of the small intestine. Within 1 month, among the vessels of the microvasculature, a violation of the classical type of branching was observed; increased vascular permeability. By the end of the 2nd month, signs of dyscirculatory disorders were revealed, the most pronounced in the vessels of the submucosa, the presence of enlargements, alternating with spasmodic areas, was noted. The permeability of the vessel wall is significantly increased. By the end of the 4th month, an increase in signs of changes was revealed, especially in the vessels of the submucosa and mesentery. The vascular wall became maximally thickened, lost the clarity of the contours due to plasma soaking and cell infiltration. Collagen deposits increased not only in the perivascular space, but also in the vascular wall. The results of studies of the recovery period testified to the continuing trends of morphofunctional transformations in the vessels of the wall of the small intestine.

reservation of soluble organic nitrogen sources, their distribution and redistribution between the main poles<...>They were also the main products transporting nitrogen along the root in the apical and radial directions.<...>Therefore, the revealed features of the basal-apical distribution of amino acids and amides along the root are<...>In the absence of nitrates in the medium, most of the amino acids formed in the root moved to the apical<...>is the result of metabolic activity and interaction, primarily of two main “poles

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Epithelial tissues, or epithelium, are part of the skin, line the serous and mucous membranes of internal organs, and also form glands. In this regard, the integumentary and glandular epithelium are distinguished.

Integumentary epithelium

The integumentary epithelium is a continuous single-layer or multilayer sheet of epithelial cells that delimits the internal environment of the body from the external environment. This tissue is found in many organs, participates in their morphogenetic processes and is characterized by a wide variety of cellular structure and functional properties. Cells in the epithelial layer are closely interconnected by specialized intercellular contacts different types. Common feature- the presence of a basement membrane (BM), delimiting the epithelium from the underlying connective tissue (or connecting it to it). BM is a carbohydrate-lipid-protein complex with a thickness of 300 nm to 1 micron. It consists of two parts of a basal lamina of a homogeneous consistency and a network of fibers. In epithelia, BM is often represented only by the basal lamina and serves as an elastic base involved in diffuse nutrition of the epithelium. Epithelial cells are characterized by a clear polarity (vertical anisomorphism): the cells distinguish between the apical and basal poles. The apical one faces the external environment and can be specialized (have microvilli, cilia, invaginations, etc.), the basal one lies on the basal plate and is connected with it by semi-desmosomes. It has been established that the basal lamina itself is a derivative of this type of epithelium.

The integumentary epithelium is involved in the exchange of substances between the body and the environment, protects the underlying tissues from mechanical, physical, chemical and other harmful factors. Some integumentary epithelia perform the function of absorption or excretion of metabolic products (excretion). Developed morphological and genetic classification epithelium.

Morphological classification... It is based on the structural features of the epithelium, taking into account the ratio of cells to the basal membrane, their shape, and vertical anisomorphism.

Monolayer epithelium is characterized by the fact that all cells of the layer lie on the basement membrane. In a monolayer single-row epithelium, all cells are of the same shape and height, and the nuclei lie at the same level. In accordance with the shape of the cells, the monolayer uniserial epithelium is subdivided into flat, cubic and columnar (prismatic).

In a monolayer multilayered epithelium, cells of various shapes and heights, and their basal poles lie on the basement membrane. The apical poles of some cells do not reach the free surface, so the nuclei are arranged in several rows. Vertical | anisomorphism in monolayer epithelium can be expressed by the presence of ciliated cilia or microvilli at the apical poles of epithelial cells.

The stratified epithelium is characterized by the fact that only the cells of the innermost layer are in direct contact with the basement membrane, and the rest, overlying layers, lose their connection with it and are located one above the other. Therefore, the epithelium is characterized by true layering and differences in the shape of cells located in different layers. According to the shape of the cells of the outer layer, the stratified epithelium is subdivided into flat and transitional. If in the stratified squamous epithelium the flattened cells of the surface layers turn into horny scales, then such an epithelium is called stratified squamous keratinizing. In the transitional epithelium, the shape of the cells of the outer layer, depending on functional state organ can vary greatly. The transitional epithelium lines the urinary tract.

Histogenetic classification. It takes into account not only the structure, but also the origin of the fabric. Taking into account that the integumentary epithelium develops from the material of all three germ layers (ectoderm, endoderm and mesoderm), the following types of epithelium are distinguished (according to I ’. Khlopin):

Epithelium of the epidermal type develops from the ectoderm, is characterized, as a rule, by a multilayer, or multi-row, structure and is mainly capable of performing a protective function (skin epidermis).

The epithelium of the enterodermal type develops from the endoderm. It is built of single-layered prismatic cells, performs an absorbing or glandular function (limb epithelium of the small intestine).

The epithelium of the celonephrodermal type is of mesodermal origin. Includes squamous epithelium (serous integument), cubic or prismatic (kidney tubules); performs a barrier or excretory function in the body.

The epithelium of the ependymoglial type develops from the material of the neural tube and lines the cavities of the brain and spinal cord.

Unilamellar flat epithelium, or mesothelium. Mesothelium lines serous points (pleura, peritoneum, epicardial sac, etc.); develops from the mesoderm, in particular from the material of its visceral and parietal leaves. Mesothelium cells are strongly flattened, polygonal (height about 0.5 µm in the area of the nucleus, 0.2 µm along the periphery), with uneven edges (Fig. 4.1). There are multinucleated mesothelial cells. A few microvilli are found on the free surface of some cells. The cells are in contact with each other through desmosomes and invaginations. This epithelium facilitates the sliding of the contacting organs relative to each other. Physiological regeneration of the mesothelium proceeds very intensively due to the cambial mesothelial cells diffusely located in the layer.

Monolayer uniserial prismatic epithelium. This epithelium can be developed in the distal part renal tubules, endodermal (thyroid follicles) and ectodermal (end sections of the mammary and sweat glands).

The cells of the proximal renal tubules are characterized by polarity. Microvilli are located at the apical end, and striation is found at the basal end due to invaginations of the cytoplasm. Large rounded nuclei are visible in the cells. Cells are connected to each other by endplates of the desmosome type (Fig. 4.2). Cambium is diffuse, that is, any of the cells retains the ability to mitotic division.

Monolayer uniserial columnar epithelium. This epithelium is of endodermal origin; characteristic of the mucous membrane of the middle section of the digestive tube, large bile ducts of the liver and pancreatic ducts. Cells are cylindrical or prismatic, with an oval nucleus slightly displaced towards the basal pole. In the cells lining the mucous membrane of the small intestine (enterocytes), at the apical pole there is vertical anisomorphism in the form of numerous microvilli, which are protrusions of the plasma membrane (Fig. 4.3). Microvilli are involved in the enzymatic breakdown of food (parietal digestion) and the absorption of hydrolysis products into the blood and lymph. Among the limbed enterocytes, there are goblet cells that specialize in the secretion of mucus, which protects the surface of the mucous membrane from chemical and mechanical damage... In the intestinal epithelium, cambial poorly differentiated cells are located in special areas of the mucous membrane - crypts. The mitotic division of these cells is characterized by a pronounced diurnal rhythm with a maximum of mitoses at 3 am in animals with an active diurnal lifestyle. Enterocytes are short-living cells and after 3 ... 5 days after leaving the crypt, they slough off into the intestinal lumen, being replaced by new ones.

The cells of the mucous membrane of the glandular stomach, along with the delimiting function, perform a glandular function: they secrete enzymes of cavity digestion and mucus. Water and some minerals are absorbed through the epithelium of the stomach. Cambial cells are called poorly differentiated cells of special areas of the glands.

Unilamellar, multilayer, or pseudo-stratified epithelium. This ciliated epithelium lines the airways. All epithelial cells by the basal pole are connected to the basement membrane: the apical pole does not reach the surface of all cells. Due to the fact that the nuclei of cells are located at different levels, the impression of a multi-row effect is created. In the epithelium, four types of cells are distinguished: with ciliated cilia, goblet and insertion cells of two types (Fig. 4.4). Cells with cilia attach to the basement membrane by a narrowed basal pole, and their wider apical pole reaches the free surface; more than 200 cilia can be located on it, oscillating towards the nasopharynx. Cilia retain dust, particles, microorganisms and, together with mucus, remove them from airways.

In goblet cells, which also attach to the basement membrane with a narrow base, the supranuclear part of the goblet is shaped. The cells secrete mucins on the surface of the epithelium, moisturizing the mucous membrane and having a bactericidal effect.

Inserted cells, short and long, attach to the basement membrane with a wide base; their narrowed apical pole does not reach the free surface. These poorly differentiated elements perform a cambial function, differentiating into ciliated and goblet cells. In the epithelium of this type, there are basal-granular endocrine cells producing serotonin and other bioactive amines.

V fallopian tubes and the vas deferens, there is a single-layer, two-row prismatic epithelium.

Stratified squamous non-keratinizing epithelium of ectodermal origin lines the outside of the cornea of the eye, vagina, mucous membrane anterior section digestive tube. The following layers are distinguished in it:

basal, represented by prismatic poorly differentiated cells lying on the basement membrane

spinous (intermediate), which consists of polygonal cells formed as a result of differentiation of cells of the basal layer after their mitotic division. Epithelial cells of the spinous layer are interconnected by desmosomes and other types of intercellular contacts; tonofibrils are well developed in the cytoplasm of cells;

the surface layer, represented by flat cells ending in their life cycle and exfoliating from the surface of the epithelium.

Stratified squamous keratinizing epithelium. This epithelium lines the surface of the skin, especially keratinizing on its support areas, the sole, toe crumbs). It can be distinguished:

the basal layer consists of prismatic poorly differentiated cells characterized by high mitotic activity and synthesizing special proteins that are involved in the formation of keratin filaments.

The spiny layer is represented by polygonal cells connected by desmosomes in the area of numerous processes (spines) and also retaining the ability to mitotic division. Together with the basal cells, the spinous cells form the producing, or reproductive, layer. In them, tonofilaments are combined into pum tonofibrils. In this layer, along with epithelial cells of ectodermal origin, there are pigment cells - melanocytes, which prevent the penetration of ultraviolet radiation, as well as dendrocytes, epidermal macrophages (of promonocytic origin) related to the macrophage system, and lymphocytes, which form a “local immune surveillance system” with dendritic cells.

The granular layer consists of flattened cells containing granules of two types in the cytoplasm. Large basophilic granules (0 ... 1 nm contain profilaggrin, which is necessary for the formation of a horny substance - keratin; in small granules (250 nm) of an elongated shape with a lamellar structure - a number of enzymes and lipids, which, during exocytosis of granules in the overlying layers, enter the intercellular space and perform a barrier function, ensuring the waterproofness of the epithelium.

The lustrous layer is formed by flat cells, in which the processes of keratinization are completed and keratohyalin is converted into a complex protein eleidin, which strongly refracts light and is a complex of keratohyalin with tonofibrils.

The stratum corneum is the most superficial. Cells move into it from the lustrous layer and lose the nucleus and all organelles. The complex of keratohyalin with tonofibrils is converted here into keratinofibrils. The cells of the stratum corneum are dead and resemble polyhedral scales in shape. They are filled with tightly packed keratin fibrils and air bubbles. Losing connection with each other, cells gradually slough off, being replaced by new ones due to reproduction, differentiation and migration from the underlying layers.

Physiological and reparative regeneration of stratified squamous keratinizing epithelium is quite high and is realized due to the division of a large number of poorly differentiated stem cells of the basal and spinous layers. The epithelium is completely renewed in about 20 days. The main functions of the epithelium are mechanical, chemical and immune protection, as well as some others.

Transitional epithelium It develops from the mesoderm frogonadotomes and lines the urinary tract - renal pelvis, ureters, bladder... The walls of these organs are significantly stretched when filled with urine. There are three layers in the epithelium.

Basal is represented by small round or triangular poorly differentiated cells associated with the basement membrane; the intermediate one consists of cells of a polygonal shape and of various sizes;

superficial contains large (often binucleated) cells of a flattened or pear-shaped form. When the walls of the organ are stretched, the cells of the surface layer flatten, and when they contract, they acquire a pear-shaped shape. At the same time, the thickness of the formation also changes. The cells of the surface layer are connected by tight contacts. The plasmolemma of cells is adapted for stretching: it has numerous invaginations and disc-shaped (in sections) vesicles, which serve as reserves of the plasmolemma during stretching. The epithelium protects the underlying connective tissue from exposure to urine.

All the listed types of integumentary epithelium are classified as rapidly regenerating tissues, which regenerate very intensively for the multiplication of poorly differentiated stem cells located in the germinal basal layers (stratified epithelium) or in the newly divided sections of the layer (single layer).

Glandular epithelium

The glandular epithelium is represented by secretory (glandular) cells - glandulocytes. They synthesize and secrete specific products (secret). If the secret is released into the external environment (on the surface of the skin or into the cavity of internal organs), then the glandulocytes are called exocrinocytes, and if into the blood - endocrinocytes. In the formation and secretion of secretions, a number of phases can be distinguished: entry into the cell by endocytosis of certain organic and mineral substances; synthesis in the endoplasmic reticulum of secretion and its accumulation in the form of granules in the lamellar complex; removal of secretory granules from the cell, restoration of the cell structure. Granules can be excreted from glandulocytes in three ways, and therefore there are three types of secretion:

merocrine (eccrine) - the secret is removed from the cell by exocytosis (for example, cells of the salivary glands);

apocrine - together with secretory granules, necta particles are separated (for example, in mammary glandulocytes, the apical part is separated - macroapocrine secretion, or only the top of microvilli - microapocrine secretion);

holocrine, which is characterized by the complete destruction of the glandulocyte and its transformation into a secret (for example, the cells of the sebaceous glands). After the end of secretion in the cell, intracellular organelles are restored - reparative regeneration begins, the duration of which is limited by the type of secretion.

Secretory cells can be located either singly (for example, goblet cells of the intestinal epithelium), or form independent anatomical organs or parts of organs called glands. The latter are divided into two groups: endocrine glands, or endocrine, and external secretion, or exocrine.

Endocrine glands. They produce highly active biological substances of various nature - hormones that go directly into the blood. The cells of the glands are in direct contact with the hemocapillaries, located in the form of strands, lobules, devoid of excretory ducts.

Exocrine glands. They develop a secret that is released into the external environment. In addition to the secretory part, or end sections, they have excretory ducts. In the glands of ectodermal origin, in the end sections, in addition to glandulocytes, there is a layer of myoepithelial (basket-like) cells.

And the longitudinal axis of the body or outgrowth of the body

Abaxial(antonym: adaxial) - located further from the axis.
Adaxial(antonym: abaxial) - located closer to the axis.
Apical (antonym: basal) - located at the top.
Basal(antonym: apical) - located at the base.
Distal(antonym: proximal) - distant.
Lateral(antonym: medial) - lateral, lying further from the median plane.
Medial(antonym: lateral) - median, located closer to the median plane.
Proximal(antonym: distal) - close.

Position relative to the main body parts

Aboral(antonym: adoral) - located on the opposite pole of the mouth of the body.
Adoral(oral) (antonym: aboral) - located near the mouth.
Abdominal- related to the abdomen.
Ventral(antonym: dorsal) - abdominal (anterior).
Dorsal(antonym: ventral) - dorsal (back).
Caudal(antonym: cranial) - caudal, located closer to the tail or to the rear end of the body.
Cranial(antonym: caudal) - head, located closer to the head or to the front end of the body.
Rostral- nasal, letters. "Located closer to the beak"; located closer to the head or to the front end of the body.

Basic planes and cuts

Sagittal- an incision in the plane of bilateral symmetry of the body.
Parasagittal- an incision running parallel to the plane of bilateral symmetry of the body.
Frontal- a cut running along front-rear axle body perpendicular to the sagittal.
Axial- an incision in the transverse plane of the body

Methods of drug administration

orally- through the mouth;
intradermally, intradermally(English intracutaneous or intradermal);
subcutaneously(English subcutaneous);
intramuscularly(English intramuscular);
intravenously(English intravenous);
intra-arterial;
intraosseous;
rectally- through the anus;
sublingually- under the tongue;
buccal- between the upper lip and the gum;
vaginally- through the vagina.

Directions

In animals, there is usually a head at one end of the body, and a tail at the opposite end. The head end in anatomy is called cranial, cranialis (lat. cranium"Skull"), and the tail is called caudal, caudalis ( cauda"tail"). On the head itself, they are guided by the nose of the animal, and the direction to its tip is called rostral, rostralis ( rostrum"beak; nose").

The surface or side of the animal's body directed upward, against the force of gravity, is called dorsal, dorsalis ( dorsum"Back"), and the opposite side of the body, which is closest to the ground, when the animal is in its natural position, that is, it walks, flies or swims - ventral, ventralis ( venter"stomach"). For example, a dolphin's dorsal fin is located dorsally, and the udder of the cow on ventral side.

Front, anterior, and rear, posterior, correspond to the concepts dorsal and ventral(however, in the case of four-legged animals capable of upright stance, the terms front and rear incorrect: concepts should be used dorsal and ventral).

Central- located in the center of the body or anatomical region;
peripheral- external, remote from the center.

When describing the position of organs lying at different depths, the following terms are used: deep, profundus, and surface, superficialis.

Concepts outer, externus, and interior, internus are used to describe the position of structures in relation to various body cavities.

The term visceral, visceralis(viscerus - interior) denote belonging and proximity to any organ. A parietal, parietalis(paries - wall) - means related to any wall. For example, visceral pleura covers the lungs, while parietal the pleura covers the inner surface of the chest wall.

Limbs

Surface upper limb relative to the palm is designated by the term palmaris - palmar, and the lower limb relative to the sole - plantaris - plantar.

Anterogradny is called movement along the natural flow of fluids and intestinal contents, while movement against the natural flow is called retrograde... So, the movement of food from the mouth to the stomach anterograde, and with vomiting - retrograde.

Mnemonic rules

To memorize the direction of movement of the hand during supination and pronation, an analogy with the phrase is usually used "I'm carrying soup, spilled soup".

The student is asked to stretch his hand forward, palm up (forward with a hanging limb) and imagine that he is holding a bowl of soup on his hand - "I'm bringing soup"- supination. Then he turns his hand palm down (back with a free-hanging limb) - "Spilled soup"- pronation.

Epithelial tissue, or epithelium(from the Greek. epi- over and thele- nipple) - border tissues covering the surface of the body and lining its cavities, mucous membranes of internal organs. Also, the epithelium is formed by glands (glandular epithelium) and receptor cells in the sensory organs (sensory epithelium).

1. Lecture: EPITELIAL FABRICS. COVER EPITHELIUM 1.

2. Lecture: EPITELIAL FABRICS. COVER EPITHELIA 2.

3. Lecture: EPITELIAL FABRICS. Iron epithelium

Types of epithelial tissue: 1. Integumentary epithelium, 2. Glandular epithelium (form glands) and can be distinguished 3) Sensory epithelium.

General morphological signs epithelium as tissue:

1) Epithelial cells are located tightly to each other, forming layers of cells;

2) The epithelium is characterized by the presence of a basement membrane - a special non-cellular formation, which creates the basis for the epithelium, provides barrier and trophic functions;

3) There is practically no intercellular substance;

4) There are intercellular contacts between the cells;

5) For epithelial cells, polarity is characteristic - the presence of functionally unequal cell surfaces: apical surface (pole), basal (facing the basement membrane) and lateral surfaces.

6) Vertical anisomorphism - unequal morphological properties of cells of different layers of the epithelial layer in stratified epithelium. Horizontal anisomorphism - unequal morphological properties of cells in monolayer epithelium.

7) There are no vessels in the epithelium; nutrition is carried out by diffusion of substances through the basement membrane from the vessels of the connective tissue;

8) Most epitheliums are characterized by a high capacity for regeneration - physiological and reparative, which is carried out thanks to cambial cells.

The surfaces of the epithelial cells (basal, lateral, apical) have a distinct structural and functional specialization, which is especially well revealed in the monolayer epithelium, including in the glandular epithelium.

Lateral surface of epithelial cells ensures the interaction of cells due to intercellular connections, which determine the mechanical connection of epithelial cells with each other - these are tight contacts, desmosomes, interdigitation, and slit contacts provide the exchange of chemical substances (metabolic, ionic and electrical communication).

Basal surface of epithelial cells adjoins the basement membrane, with which it is connected with the help of semi-desmos. The basal and lateral surfaces of the plasmolemma of the epithelial cell together form a single complex, the membrane proteins of which are: a) receptors that receive various signaling molecules, b) carriers of nutrients coming from the vessels of the underlying connective tissue, c) ion pumps, etc.

Basement membrane(BM) binds epithelial cells and the underlying loose fibrous connective tissue. At the light-optical level, on histological preparations, BM has the form of a thin strip, poorly stained with hematoxylin and eosin. At the ultrastructural level, three layers are distinguished in the basement membrane (in the direction from the epithelium): 1) the light plate, which connects with the epithelial hemismosomes, contains glycoproteins (laminin) and proteoglycans (heparan sulfate), 2) the dense plate contains collagen IV, V, VII types , It has fibrillar structure... Thin anchor filaments cross the light and dense plate, passing into 3) the reticular plate, where the anchor filaments bind to collagen (collagen I and II types) fibrils of the connective tissue.

Under physiological conditions, BM prevents the growth of the epithelium towards the connective tissue, which is disrupted in malignant growth, when cancer cells grow through the basement membrane into the underlying connective tissue (invasive tumor growth).

Apical surface of epithelial cells may be relatively smooth or bulging. Some epithelial cells have special organelles on it - microvilli or cilia. Microvilli are maximally developed in epithelial cells involved in absorption processes (for example, in small intestine or the tubules of the proximal nephron), where their totality is called the brush (striated) border.

Microcilia are mobile structures containing microtubule complexes inside.

Sources of epithelium development... Epithelial tissues develop from three germ layers, starting from 3-4 weeks of human embryonic development. Depending on the embryonic source, the epithelium of ectodermal, mesodermal and endodermal origin is distinguished.

Morphofunctional classification of epithelial tissue

I. Integumentary epithelium

1. Monolayer epithelium - all cells lie on the basement membrane:

1.1. Single-row epithelium (cell nuclei at the same level): flat, cubic, prismatic;

1.2. Multi-row epithelium (cell nuclei at different levels due to horizontal anisomorphism): prismatic ciliate;

2. Stratified epithelium - only the lower layer of cells is connected to the basement membrane, the overlying layers are located on the underlying layers:

2.1. Flat - keratinizing, non-keratinizing

3. Transitional epithelium - occupies an intermediate position between single-layer multilayer and stratified epithelium

II. Glandular epithelium:

1.With exocrine secretion

2.With endocrine secretion

SINGLE-LAYER EPITHELIA

Unilamellar squamous epithelium formed by flattened polygonal cells. Localization examples: mesothelium covering the lung (visceral pleura); the epithelium lining the inside of the chest cavity (parietal pleura), as well as the parietal and visceral sheets of the peritoneum, the pericardial sac. This epithelium allows organs to come into contact with each other in cavities.

Monolayer uniserial cubic epithelium formed by cells containing a spherical nucleus. Localization examples: thyroid follicles, small pancreatic ducts and bile ducts, renal tubules.

Monolayer single-row prismatic (cylindrical) epithelium formed by cells with a pronounced polarity. The elliptical nucleus lies along the long axis of the cell and is displaced to their basal part, the organelles are unevenly distributed over the cytoplasm. On the apical surface there are microvilli and a brush border. Examples of localization: the lining of the inner surface of the small and large intestine, stomach, gallbladder, a number of large ducts of the pancreas and bile ducts of the liver. This type of epithelium is characterized by the functions of secretion and (or) absorption.

Unilamellar, multi-row ciliated (ciliated) epithelium airways formed by cells of several types: 1) low intercalary (basal), 2) high intercalary (intermediate), 3) ciliated (ciliated), 4) goblet. Low intercalated cells are cambial, with their wide base they adjoin the basement membrane, and with their narrow apical part they do not reach the lumen. Goblet cells produce mucus that covers the surface of the epithelium, moving along the surface due to the beating of the cilia of the ciliated cells. The apical parts of these cells are adjacent to the lumen of the organ.

MULTILAYER EPITHELIA

Stratified squamous keratinizing epithelium(MOPE) forms outer layer skin - the epidermis, and covers some areas of the oral mucosa. MPOE consists of five layers: basal, spinous, granular, shining (not present everywhere), and stratum corneum.

Basal layer formed by cells of a cubic or prismatic shape, lying on the basement membrane. Cells divide by mitosis - this is the cambial layer from which all the overlying layers are formed.

Prickly layer formed by large cells of irregular shape. Dividing cells can occur in the deep layers. In the basal and prickly layers, tonofibrils (bundles of tonofilaments) are well developed, and desmosomal, dense, slit-like contacts between the cells.

Granular layer consists of flattened cells - keratinocytes, the cytoplasm of which contains grains of keratohyalin - a fibrillar protein that, in the process of keratinization, turns into eleidin and keratin.

Shiny layer expressed only in the epithelium of the thick skin covering the palms and soles. The lustrous layer is the zone of transition from living cells of the granular layer to the scales of the stratum corneum. On histological preparations, it looks like a narrow oxyphilic homogeneous strip and consists of flattened cells.

Stratum corneum consists of horny scales - postcellular structures. Keratinization processes begin in the prickly layer. The stratum corneum has the maximum thickness in the epidermis of the skin of the palms and soles. The essence of keratinization is to ensure the protective function of the skin from external influences.

Differon keratinocyte includes cells of all layers of this epithelium: basal, prickly, granular, shiny, horny. In addition to keratinocytes, a small amount of melanocytes, macrophages (Langerhans cells) and Merkel cells are present in the stratified keratinizing epithelium (see the topic "Skin").

The epidermis is dominated by keratinocytes, organized according to the columnar principle: cells at different stages of differentiation are located one above the other. At the base of the column are cambial poorly differentiated cells of the basal layer, the top of the column is the stratum corneum. The keratinocyte column includes the differention cells of the keratinocytes. The columnar principle of epidermal organization plays a role in tissue regeneration.

Stratified squamous non-keratinizing epithelium covers the surface of the cornea of the eye, oral mucosa, esophagus, vagina. It is formed by three layers: basal, prickly and superficial. The basal layer is similar in structure and function to the corresponding layer of the keratinizing epithelium. The spinous layer is formed by large polygonal cells, which flatten as they approach the surface layer. Their cytoplasm is filled with numerous tonofilaments, which are located diffusely. The surface layer consists of polygonal flat cells. Nucleus with poorly distinguishable chromatin granules (pycnotic). During desquamation, the cells of this layer are constantly removed from the surface of the epithelium.

Due to the availability and ease of obtaining the material, the stratified squamous epithelium of the oral mucosa is a convenient object for cytological studies. Cells are obtained by scraping, smear or print. Then they are transferred onto a glass slide and a permanent or temporary cytological preparation is prepared. The most widespread diagnostic cytological examination this epithelium in order to identify the genetic sex of the individual; violations of the normal course of the process of differentiation of the epithelium during the development of inflammatory, precancerous or tumor processes of the oral cavity.

3. Transitional epithelium - a special type of stratified epithelium that lines most of urinary tract... It is formed by three layers: basal, intermediate and superficial. The basal layer is formed by small cells that have a triangular cut on the cut and with their wide base adjoin the basement membrane. The intermediate layer consists of elongated cells, with a narrower part adjacent to the basement membrane. The surface layer is formed by large mononuclear polyploid or binuclear cells, which change their shape to the greatest extent when the epithelium is stretched (from round to flat). This is facilitated by the formation in the apical part of the cytoplasm of these cells at rest of numerous invaginations of the plasmolemma and special disc-shaped vesicles - the reserves of the plasmolemma, which are incorporated into it as the organ and cells are stretched.

Regeneration of integumentary epithelium... The integumentary epithelium, occupying a borderline position, is constantly influenced by the external environment, so the epithelial cells quickly wear out and die. In a monolayer epithelium, most cells are capable of division, while in a multilayer epithelium, only cells of the basal and partially prickly layers have this ability. The integumentary epithelium is characterized by a high degree of regeneration ability, and in this regard, up to 90% of all tumors in the body develop from this tissue.

Histogenetic classification of integumentary epithelium(according to N.G. Khlopin): there are 5 main types of epithelium developing in embryogenesis from various tissue rudiments:

1) Epidermal - formed from the ectoderm, has a multilayer or multi-row structure, performs a barrier and protective function... For example - the epithelium of the skin.

2) Enterodermal - develops from the intestinal endoderm, is single-layer cylindrical in structure, carries out the processes of absorption of substances. For example, the intestinal epithelium.

3) Celonephrodermal - has a mesodermal origin (coelomic lining, nephrotome), in structure it is single-layer, flat or prismatic, performs mainly a barrier or excretory function. For example, the epithelium of the kidneys.

4) Angiodermal - includes endothelial cells of mesenchymal origin (angioblast).

5) Ependymoglial type is presented special kind tissue of neural origin (neural tube), lining the brain cavity and having a structure similar to the epithelium. For example, ependymal gliocytes.

Iron epithelium

Glandular epithelial cells can be singly located, but more often form glands. The cells of the glandular epithelium are glandulocytes or glandular cells, the secretion process in them proceeds cyclically, is called the secretory cycle and includes five stages:

1. The phase of absorption of the initial substances (from blood or intercellular fluid), from which the final product (secret) is formed;

2. The phase of secretion synthesis is associated with the processes of transcription and translation, the activity of gEPS and agrEPS, the Golgi complex.

3. The phase of secretion maturation occurs in the Golgi apparatus: dehydration and the addition of additional molecules occurs.

4. The phase of accumulation of the synthesized product in the cytoplasm of glandular cells is usually manifested by an increase in the content of secretory granules, which may be contained in membranes.

5. The phase of excretion of secretion can be carried out in several ways: 1) without disrupting the integrity of the cell (merocrine type of secretion), 2) with the destruction of the apical part of the cytoplasm (apocrine type of secretion), with complete disruption of the integrity of the cell (holocrine type of secretion).

The glands are divided into two groups: 1) endocrine glands, or endocrine glands, which produce hormones - substances with high biological activity. There are no excretory ducts, the secret enters the blood through the capillaries;

and 2) exocrine glands, or exocrine glands, in which the secret is released into the external environment. Exocrine glands consist of end (secretory) and excretory ducts.

The structure of the exocrine glands

The terminal (secretory) sections are composed of glandular cells (glandulocytes) that produce secretions. The cells are located on the basement membrane, they are characterized by pronounced polarity: the plasmolemma has a different structure on the apical (microvilli), basal (interaction with the basement membrane) and lateral (intercellular contacts) surfaces of cells. Secretory granules are present in the apical part of the cells. In cells that produce secrets of a protein nature (for example: digestive enzymes), GRES is well developed. In cells synthesized by non-protein secrets (lipids, steroids), aEPS is expressed.

In some glands formed by epithelium of the epidermal type (for example, sweat, milk, salivary), the terminal sections, in addition to the glandular cells, contain myoepithelial cells - modified epithelial cells with a developed contractile apparatus. Myoepithelial cells with their processes cover the outside of the glandular cells and, by contracting, contribute to the release of secretions from the cells of the terminal section.

The excretory ducts connect the secretory sections with the integumentary epithelium and provide the release of synthesized substances to the surface of the body or into the cavity of organs.

The division into end sections and excretory ducts is difficult in some glands (for example, stomach, uterus), since all parts of these simple glands are capable of secretion.

Classification of exocrine glands

I. Morphological classification exocrine glands is based on a structural analysis of their terminal sections and excretory ducts.

Depending on the shape of the secretory (end) section, there are alveolar, tubular and mixed (alveolar-tubular) glands;

Depending on the branching of the secretory department, branched and unbranched glands are distinguished.

The branching of the excretory ducts determines the division of the glands into simple (the duct does not branch) and complex (the duct branches).

II. By chemical composition the secretion produced is distinguished by serous (protein), mucous, mixed (protein-mucous), lipid and other glands.

III. By the mechanism (method) of excretion secretion exocrine glands are divided into apocrine (mammary gland), holocrine ( sebaceous gland) and merocrine (most glands).

Examples of the classification of glands. Classification characteristic sebaceous gland skin: 1) a simple alveolar gland with branched end sections, 2) lipid - according to the chemical composition of the secretion, 3) holocrine - according to the method of secretion excretion.

Characteristic lactating (secreting) breast: 1) a complex branched alveolar-tubular gland, 2) with mixed secretion, 3) apocrine.

Regeneration of the glands... The secretory cells of the merocrine and apocrine glands belong to stable (long-lived) cell populations, which is why they are characterized by intracellular regeneration. In the holocrine glands, restoration is carried out due to the multiplication of cambial (stem) cells, i.e. cell regeneration is characteristic: newly formed cells differentiate into mature cells.