The program of the elective course "Biology of farm animals with the basics of veterinary medicine" includes theoretical knowledge in anatomy, physiology, veterinary medicine and a laboratory workshop, is the same for teaching boys and girls.
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MKOU Northern School
Agreed: "Approve"
Deputy director for water resources management director of the school
Osipova G.A. Vinogradova N.M.
"___" ________ 2016 "___" _________ 2016
Working programm
in biology
elective course "Biology of agricultural
animals with the basics of veterinary medicine»
in 11th grade
number of hours per week - 1
methodical association of teachers of natural sciences (physics, chemistry, biology)
teacher: Osipova Tatyana Nikolaevna
Compiled in accordance with the program in biology for educational institutions to a set of textbooks created under the guidance of V.V. Pasechnik
Passed examination at the meeting methodical association, Protocol No. ____ dated "____" _____ 2016.
The program of the elective course "Biology of farm animals with the basics of veterinary medicine"
GRADE 11
(for chemical - biological profile)
The duration of the course is 1 year. 1 hour per week.
Number of hours - anatomy, physiology of farm animals - 28 hours; basics of veterinary medicine - 6 hours.
Total - 34 hours.
Explanatory note
AT modern conditions development of the village becomes effective activity of people in farming peasant farms. Animal husbandry requires knowledge in the field of anatomy, physiology of domestic animals, zootechnics and veterinary medicine.
The program of the elective course "Biology of farm animals with the basics of veterinary medicine" includes theoretical knowledge in anatomy, physiology, veterinary medicine and a laboratory workshop, is the same for teaching boys and girls. In the learning process, students' knowledge is used not only in biology, but also in physics, chemistry, and technology. The main forms of education are theoretical and laboratory classes.
The course is closely related to the section of biology "Animals". This program allows you to specifically study the anatomy, physiology of domestic animals. The sections "Anatomy, physiology of farm animals" and "Fundamentals of veterinary medicine" can be used in teaching as separate modules.
Program goals:
Deepen knowledge in the field of animal husbandry, consolidate acquired skills;
Mastering the knowledge of the basics of animal husbandry and veterinary medicine, necessary for admission to secondary specialized and higher educational institutions, as well as agricultural institutions in the specialties: veterinary medicine, animal husbandry.
Program objectives:
- Familiarization of students with the biological characteristics of farm animals;
- Formation of their zootechnical and veterinary knowledge and skills necessary to perform the basic work of caring for pets.
Planned results:
- Students should know:
- the importance and main branches of animal husbandry;
- types of farm animals, their biological characteristics;
Anatomy, physiology of farm animals, directions of their productivity;
Methods for determining diseases of agricultural animals, methods for their treatment and prevention;
Fundamentals of veterinary medicine and zootechnics;
Systems and methods of keeping agricultural animals, the basics of labor organization in animal husbandry.
2 . Students should be able to:
Determine the types of farm animals and their productivity;
Use in practice knowledge of anatomy, physiology, zoohygiene and veterinary medicine;
take care of animals;
To carry out the simplest diagnosis and treatment of certain diseases, to comply with sanitary and hygienic requirements.
The course will also help:
Formation of personal attitude to agricultural work, further choice of profession;
Awareness of the importance of agricultural labor;
The development of professional skills for the activities of future farmers - livestock breeders in modern conditions for the development of agricultural production.
Career guidance effect of the program:
- Definition future profession, preparation for training in secondary special and higher educational institutions.
Educational and material base:
- Personal farm.
- Textbook "Biology of farm animals with the basics of veterinary medicine" (author V.M. Zhukov, edited by G.V. Nebogatikov)
Calendar - thematic planning of the elective course "Biology of farm animals with the basics of veterinary medicine"
the date | Topic of the lesson | Number of hours |
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Theory | Practice |
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Subject of anatomy, physiology of agricultural animals | ||||
The structure and functions of animal cells. | ||||
The concept of animal tissues. | ||||
Organs and systems of organs of agricultural animals | ||||
Oprono - the motor system of agricultural animals (skeleton). | ||||
The muscular system Animals. | ||||
The skin, its structure and functions. | ||||
Mammary glands (cow's udder) | ||||
The digestive system and its functions (structure, features of digestion in animals with a single-chamber and multi-chamber stomach) | ||||
Pathology of the digestive system, treatment and prevention of diseases of the digestive system. | ||||
Blood, its composition and functions. | ||||
The cardiovascular system. Blood circulation and lymph circulation. | ||||
Pathology of the circulatory organs and its treatment. | ||||
Respiratory system and its functions. | ||||
Treatment of pathologies of the respiratory system. | ||||
Reproductive system. | ||||
Care of newborns and youngsters. | ||||
Metabolism and energy. | ||||
metabolic pathology. | ||||
Urinary organs. | ||||
Endocrine glands. | ||||
Nervous system and its functions. | ||||
Conditioned and unconditioned reflexes. | ||||
Origin of farm animals. | ||||
Breeds of domestic animals (fish, birds). | ||||
Breeds of domestic animals (mammals: sheep, pigs, cows, horses). | ||||
Conditions for keeping and caring for farm animals. | ||||
"The structure of the animal cell", "The structure of the skin", "The structure of the blood" | l/r |
|||
“The main parts of the skeleton of a horse, a cow. The structure of individual bones, the connection of bones " | l/r |
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"Topography of the internal organs of animals" | l/r |
|||
Fundamentals of clinical diagnostics of domestic animals. | ||||
Diseases common to humans and animals, diagnosis, principles of treatment. | ||||
Storage and processing of agricultural products. | ||||
General lesson "The role of agricultural animals for humans" | ||||
The manual presents the program and approximate content of the elective course "Biology of farm animals with the basics of veterinary medicine".
Its purpose is to deepen and expand students' knowledge of biology, chemistry, physics and technology, to develop and maintain their cognitive interest in animal husbandry, to promote an informed choice of profession.
The proposed activities in the course of theoretical classes, planned excursions, as practical tasks and laboratory work are completed, will help in the formation of self-educational skills of high school students.
The manual will help teachers of biology and technology in the organization of specialized education.
Detailed description
Program
elective course
"Biology of Farm Animals
with the basics of veterinary medicine "
(for chemical and biological
and agricultural profile)
The duration of the course is 2 years, 1 hour per week.
Number of hours - anatomy, physiology of farm animals - 34 hours; basics of veterinary medicine - 34 hours.
Total - 68 hours.
EXPLANATORY NOTE
In modern conditions of rural development, the activity of people in farming peasant farms becomes effective. Animal husbandry requires knowledge in the field of anatomy, physiology of domestic animals, zootechnics and veterinary medicine.
The program of the elective course "Biology of farm animals with the basics of veterinary medicine" includes theoretical knowledge in anatomy, physiology, veterinary medicine and a laboratory workshop, is the same for teaching boys and girls. In the learning process, students' knowledge is used not only in biology, but also in physics, chemistry, and technology. The main forms of organizing student learning are theoretical and practical classes, excursions to a livestock farm, practice in caring for animals and milking cows. Practical training is organized at the workplaces of livestock farm operators. The content of labor must correspond to the age and physiological characteristics of students and meet the sanitary and hygienic requirements for the work of minors and labor safety rules. Students are not allowed to participate in the care of sick animals.
The course is in close contact with the section of biology "Animals", is the basis for studying the course "Man and his health". The study of this elective course is recommended after completing the course "Animals" on the topic "Mammals" or the course "Anatomy, Physiology, Human Hygiene". This program allows you to specifically study the anatomy, physiology of a large cattle(cows), is the basis for studying the course "The owner (owner) of a rural estate."
The sections "Anatomy, physiology of farm animals" and "Fundamentals of veterinary medicine" can be used in teaching as separate modules.
Program goals:
- deepening knowledge in the field of animal husbandry, consolidating the acquired skills;
- mastering the knowledge of the basics of animal husbandry and veterinary medicine, necessary for admission to secondary specialized and higher educational institutions of the agricultural direction in the specialties: veterinary medicine, animal husbandry.
Program objectives:
1) familiarization of students with the biological characteristics of farm animals;
2) the formation of their zootechnical and veterinary knowledge and skills necessary to perform the basic work of caring for animals.
Planned results:
1) Students should know:
- the importance and main branches of animal husbandry;
- types of farm animals, their biological characteristics;
- anatomy, physiology of farm animals, directions of their productivity;
- methods for determining diseases of agricultural animals, methods for their treatment and prevention;
- Fundamentals of veterinary medicine and zootechnics;
– physiological bases of milking of agricultural animals, systems and methods of their maintenance, basics of labor organization in animal husbandry.
2) Students should be able to:
- to determine the types of farm animals and their productivity;
– use in practice knowledge of anatomy, physiology, zoohygiene and veterinary medicine;
- taking care of animals
- carry out diagnostics and treatment of certain diseases under the guidance of specialists, comply with sanitary and hygienic requirements and labor safety rules.
The course will also help:
- the formation of a personal attitude to agricultural work, the choice of a profile, the further choice of a profession;
– awareness of the importance of agricultural labor;
– development of professional skills of future livestock farmers in modern conditions of development of agricultural production.
Career guidance effect of the program:
1) the study of the basics of animal husbandry and veterinary medicine lays the foundation for mastering the students' specialties: operator of machine milking cows, operator livestock farm;
2) in cooperation with universities of the agricultural direction (veterinarian faculty), by the efforts of teachers of these universities, it is possible to train students in the specialty "veterinary assistant" using the existing material base of the school or lyceum;
3) determination of the future profession, preparation for training in specialized secondary and higher educational institutions of animal husbandry.
Educational and material base:
1) animal husbandry cabinet;
2) mini-farm of cattle (cows);
3) tutorial"Biology of farm animals with the basics of veterinary medicine" (author V. M. Zhukov, edited by G. V. Nebogatikov);
4) the textbook "Fundamentals of Veterinary Medicine" (author V. M. Zhukov, edited by G. V. Nebogatikov).
The program of the elective course "Biology of farm animals with the basics of veterinary medicine" (for the chemical-biological and agricultural profile) 3
Literature 8
Apps 8
Blood, its composition and functions 76
Respiratory system and its functions 87
Metabolism and energy 92
Urinary organs 98
Laboratory work "Topography of internal organs, their forms, structure and physiology" 103
Endocrine glands 106
Nervous system and its functions 110
Central nervous system of farm animals 115
Departments of the nervous system (peripheral and vegetative) of an agricultural animal 118
Conditioned reflexes and their significance in animal husbandry 122
Origin of farm animals 128
Diseases common to humans and animals. Diagnosis, principles of treatment (Modular lesson) 131
Literature 167
All types of domestic animals are descended from wild ancestors. During excavations of settlements of people who lived in ancient times, many millennia BC, bones of domestic animals, drawings on the walls of ancient dwellings, on dishes, utensils depicting the capture of wild animals and their taming were found. Tamed animals gave offspring that grew up near a person and enjoyed his patronage. The domestication of animals was also facilitated by hunger, which drove them to human habitation, where food could be found.
Domestic animals and their ancestors: 1 - tamed elephants; 2, 3 - breeds of the domestic dog and its wild wolf ancestor; 4 - camels; 5, 6 - since ancient times, the horse has been widely used in war and in sports; 7 - wild ancestor of the domestic horse - tarpan; 8 - breeds of domestic chickens; 9 - wild banking chickens; 10, 11 - a domestic pig and its wild ancestor - a wild boar.
Domestic animals and their ancestors: 12 - English riding horse; 13 - images of domestic animals on ancient Egyptian frescoes testify to the developed cattle breeding; 14 - tour - the ancestor of cattle; 15 - red steppe breed of cattle; 16 - American llamas; 17, 18 - wild bezoar goat and domestic goat; 19, 20 - wild sheep argali and domestic sheep; 21 - Nubian cat - the ancestor of numerous breeds of domestic cats.
Man, noticing that tamed animals are beneficial, sought to breed them, moving from domestication to domestication. At first, domesticated animals served as a source of meat food for people. Later they became the faithful helpers of man.
There are two concepts: domestic and tamed animals. Pets are called animals that produce products (meat, milk, wool, eggs, etc.) and breed in captivity under human control. In contrast, domesticated animals do not breed in captivity, such as Indian elephants. Human impact on these animals was not so strong and lasting. The domestication of tamed animals was carried out gradually, under the influence of new living conditions created for them by man, by selecting individuals with useful traits and breeding their offspring. Domestic animals differ sharply from their wild ancestors, they became so thanks to the enormous work that a person has invested in improving their signs and properties in the direction he needs.
It is believed that the domestication of animals did not occur simultaneously in different parts of the world.
The oldest farm animals were sheep and goats. The wild ancestors of sheep are considered mouflon, argali, argali. European sheep are descended from the mouflon, which still lives on the islands of the Mediterranean Sea. Argali and argali are the ancestors of Asian sheep. Argali lives in the highlands of the Tien Shan, the Sayan Mountains, Kamchatka. Argali is a wild sheep that lives in our mountains of Central Asia.
Goats were domesticated before sheep. Their origin is mixed. The main ancestors of modern goats are bezoar goats living in the mountainous regions of Transcaucasia, Turkmenistan, Iran, and Himalayan markhor goats.
Human creative activity continues to involve more and more new species of animals in agricultural production. This process continues at the present time.
The structure and typography of the stomachs of a horse and a dog. Microscopic structure of the cardinal, fundus and pyloric parts
The structure and topography of the lungs of cattle and horses
The structure of the testis and appendage. Stages of spermatogenesis
Anatomical and histological structure of the lymph nodes. What function do they perform
References
1. The structure and typography of the stomachs of a horse and a dog. Microscopic structure of the cardinal, fundus and pyloric parts
The stomach in dogs is single-chamber, according to the location of the glands of the so-called intestinal type. In fact, the stomach is a reservoir between the esophagus, through which a large amount of food passes quickly in the process of eating it, and the intestines, through which the feed masses must move in small portions and relatively evenly. During its stay in the stomach, the food is processed by gastric juice, which prevents its fermentation and decay and partly ferments it.
In the stomach, the entrance or cardial part, the fundus or fundus, the body, the antrum and the pylorus or pylorus are distinguished. In general, the dog's stomach has the shape of an irregular pear, suspended with a handle down and to the right. The concave side of the stomach is called the lesser curvature, the convex side is the greater curvature. At the same time, its most voluminous part is the bottom and oral part of the body, and towards the pylorus of the stomach it narrows strongly.
Located entirely in the hypochondria, an empty or moderately filled stomach does not come into contact with the abdominal walls. The stomach is connected to the surrounding organs and walls of the abdominal cavity by ligaments. The lesser omentum, otherwise the hepatogastric ligament, connects the lesser curvature of the stomach to the hilum of the liver under the mastoid lobe. Orally, the ligament passes into the hepaoesophageal ligament, and aborally, that is, to the right, into the hepatoduodenal ligament. From the side of the greater curvature, the stomach is connected to the diaphragm by the phrenic-gastric ligament, which passes ventrally and to the left into the gastrosplenic ligament and then into the greater omentum. In the caudal direction, the splenic-colic ligament departs from the spleen.
All ligaments of the stomach hang freely, they are not stretched and do not fix the stomach, but only prevent excessive and incorrect movement of the abdominal organs. Thus, the only anatomical formation that relatively rigidly holds the stomach is the esophagus.
Diagram of the structure of the stomach of a dog
The stomach is a sac-shaped abdominal organ. The horse has a single-chamber, esophago-intestinal type. Relatively small, with a capacity of 6-15 liters. It has two surfaces: parietal (diaphragmatic), facing the diaphragm and liver, and visceral, facing the intestines.
The body of the stomach is curved. To the left, back and down the stomach is directed by a convex greater curvature, to the right, forward and upward - by a concave lesser curvature. In the region of greater curvature between the inlet and outlet parts, the wall of the stomach is called the fundus. In the stomach, there are: the entrance from the esophagus to the stomach - the cardial opening - on the left side of the stomach, the exit from the stomach into the duodenum - the pyloric opening.
There is no funnel-shaped expansion in the cardial part. Instead, a powerful muscular cardiac sphincter is formed in the wall of the stomach, covering the entrance of the esophagus to the stomach. There is also a large protrusion - a blind sac lined with a mucous membrane of the esophageal type. It is sharply separated from the intestinal mucosa by a fold and a lighter color.
The angular notch on the lesser curvature is well expressed. In the pyloric part, the annular muscles delimit the pyloric cavity and form the pyloric sphincter. The peritoneum passes to the lesser curvature of the stomach from the diaphragm and liver and forms a lesser omentum.
There are three ligaments here: gastro-diaphragmatic, gastro-hepatic and gastro-duodenal. The greater omentum begins with the greater curvature. Between its sheets is located reticular and loose connective tissue, nerves, blood vessels and the spleen, associated with the greater curvature of the stomach by the gastro-splenic ligament. The greater omentum continues and passes from the horse to the duodenum and colon.
The omentum forms a bag. The horse's stomach is located in the cranial part of the abdominal cavity (almost entirely in the left hypochondrium) and is adjacent to the diaphragm and liver. The mucous membrane in the cardial part has no glands.
2. The structure and topography of the lungs of cattle and horses
The respiratory apparatus is represented by the respiratory organs (respiratory system) and respiratory motility organs (thorax, its muscular and ligamentous apparatus, vessels and nerves). The respiratory organs are the lungs, which are placed in the chest from the 1st rib to the penultimate rib (in horses up to the 16th rib) and are covered with pleura on the outside (Fig.).
Rice. Thoracic cavity of cattle (right section): 1 - diaphragm: 2 - diaphragmatic lobe of the lung; 3 - apical lobe of the lung; 4 - the average lobe of the lung; 5 - heart; 6 - dewlap
Rice. Thoracic cavity of cattle (left section): 1 - esophagus; 2 - trachea; 3 - vagosympathetic trunk; 4 - left common carotid artery; 5 - external thoracic artery; 6 - axillary artery; 7 - external jugular vein; 8 - external thoracic vein; 9- axillary vein; 10 - internal thoracic artery; 11 - internal thoracic vein; 12 - sternocephalic muscle; 13 - thymus; 14 - apical lobe (cranial) of the lung; 15 - diaphragmatic lobe of the lung; 16 - diaphragm; 17 - apical lobe (caudal) of the lung; 18 - heart; 19 - right apical lobe of the lung
In the structure of the lungs, asymmetry is observed (the right lung is always larger than the left) and significant specific features, which is associated with the structural features of the chest and the type of breathing (abdominal in ungulates and chest, thoracoabdominal in carnivores). Each lung has a cranial, middle (except horse), and caudal lobes, and the right lung also has an accessory lobe. In the lungs, air movement occurs due to diffusion. In them, air enters through the airways, in which forced air movement is carried out. The airways include: nasal cavity, nasopharynx, larynx, trachea and bronchi. All airways have a cartilaginous framework, which ensures their constant gaping (preservation of the lumen).
The structure of the testis and appendage. Stages of spermatogenesis
The reproductive organs of males include the testes, epididymis, vas deferens, scrotum (testis sac), urogenital canal with accessory sex glands, penis and prepuce. The main reproductive gland of males is the testes with their appendages. They are located outside the abdominal and pelvic cavities and are located in the testis sac.
Testis sac - protrusion of the abdominal wall, in bulls in front of the pubic bones, stallions and males - under the pubic bones, in boars - behind the pubic bones, not far from the anus. The wall of the testis sac consists of the scrotum, the muscle - the external levator of the testis and the vaginal membranes.
The scrotum - consists of skin and a muscular-elastic membrane that fits snugly against the skin of the scrotum. The shell forms a scrotal septum, dividing the latter into two halves, each of which contains a testis with an appendage, covered with vaginal membranes: common (for the testis and the appendage) and special (separate for the testis and the appendage). Between these membranes is a cavity that communicates with the abdominal cavity through the inguinal canal.
The testis is a paired organ of an ellipsoidal shape, in which in mature animals spermatogenesis occurs and sex hormones are produced. The appendage of the testis is closely connected with it. On the testis, there are: free and adnexal margins; the capitate end, with which the head of the appendage is connected; the tail end, to which the tail of the appendage belongs; lateral and medial surfaces.
The epididymis is a continuation of the vas deferens. It consists of a head, body and tail.
Histological structure of the testis and its appendages.
The testis consists of stroma and parenchyma. Stroma, forms a protein membrane outside the testis, and inside - trabeculae dividing it into lobules filled with convoluted seminiferous tubules, turning into straight ones. The tubules are the parenchyma of the testis, which also includes interstitial cells lying between the convoluted tubules. The direct tubules pass into the efferent tubules, which flow into the canal of the appendage. The efferent tubules form the head of the appendage, the canal is the body and tail of the appendage, giving rise to the vas deferens.
The spermatic cord is a fold of a special vaginal membrane in which the testis artery and nerves pass to the testis and the epididymis, and veins, lymphatic vessels and the vas deferens depart from the testis. The spermatic cord has the appearance of a cone squeezed from the sides.
The vas deferens - in the abdominal cavity from the composition of the spermatic cord, goes caudally, passes along the dorsal surface of the bladder and flows into the urethra. The vas deferens, flowing into the urethra, form a single tubular organ - the urogenital canal, through which urine and sperm pass.
Urinary canal - starts from the confluence of the vas deferens into the urethra and ends at the head of the penis; consists of pelvic and penile parts. The pelvic part lies on the pubic and ischial bones and has accessory glands. Bending over the ischial arch, the urogenital canal passes to the ventral surface of the penis, penetrating into it and accompanying it throughout. This is the penile part of the urogenital canal. The wall of the urogenital canal consists of mucous, vascular and muscular membranes. The choroid, or cavernous body, contains a large amount of smooth muscle tissue, elastic fibers and choroid plexuses with lacunae (cavities), which fill with blood during erection. The urogenital canal opens on the head of the penis.
Accessory sex glands - vesicular, prostate and bulbous, complex alveolar-tubular structure.
The prostate gland is unpaired, consists of parietal and posterior parts. The posterior part lies on the neck of the bladder and the beginning of the urogenital canal. The parietal part is located in the wall of the urogenital canal, in its cavernous layer, between the mucous and muscular membranes. The secret of the prostate gland increases sperm motility, neutralizes the acidic environment of the vagina.
Bulbous (Cooper) gland - steam room, lies at the caudal end of the pelvic part of the urogenital canal. It secretes a secret that cleans the urogenital canal from urine residue.
Spermatogenesis is conditionally divided into four periods: reproduction, growth, maturation and formation. During the reproduction period, mitotic division of a part of the spermatogonia occurs, which are formed from the rudimentary epithelium. The growth period is characterized by an increase in the mass of the cytoplasm of spermatogonia and their transformation into spermatocytes of the 1st order. During maturation, two successive divisions of maturation occur: the first is called meiotic and the second is mitotic.
After the first division, from each spermatocyte of the 1st order, two spermatocytes of the 11th order are formed, after the second division, four spermatids with a haploid set of chromosomes are formed from them. The reduction of the genetic material occurs due to the fact that there is no DNA replication before the second division. Spermatids no longer divide. Entering the fourth period of spermatogenesis - the period of formation, they undergo complex rearrangements of cytoplasmic structures, acquire tails and turn into mature sperm. All developing germ cells, except for sperm cells, are united in the tubule by means of syncytial connections. Mature spermatozoa are much smaller than spermatogonia. In the process of development, they lose most of their cytoplasm, minor cellular components and consist only of a head containing a concentrated nuclear substance and a tail that ensures their mobility. A part of the cytoplasm with the Golgi apparatus is concentrated at the apical end of the sperm head, and an acrosome is formed from it in the head cap. This organelle plays important role when the sperm head enters the egg. The total length of sperm is 50 - 70 microns, the average volume is 16 - 19 microns. For each animal species, the time required for the transformation of spermatogonium into mature spermatozoa (including the residence time in the epididymis) is constant, although differences between species are significant. The duration of spermiogenesis is, in days: in a bull 54 in a camel 56 in a ram 49 in a rabbit 41 in a boar 34 in a male 56 in a stallion 42 in a rooster 25 Inside the testis, these are straight tubules, the network of the testis and the efferent tubules of the testis, lined with a single-layer squamous epithelium; outside the testis - the canal of the appendage and the vas deferens. The latter opens into the canal coming from the bladder, forming with it the urogenital canal, passing inside the penis. The channel is surrounded by cavernous cavernous bodies capable of swelling.
During copulation, sperm are released not directly from the testis, but from the caudal part of the epididymis. In the canal of the epididymis, sperm accumulate in large quantities (20 - 40 billion in a bull). Here they undergo further morphofunctional changes within 8–20 days. In the acidic anoxic environment of the canal of the epididymis, spermatozoa fall into a state similar to anabiosis, acquire a compacted lipoprotein membrane and a negative charge, which protects them from the action of acidic products and from agglutination in the female genital tract. In the epididymis, the antigenic properties of the sperm surface also change. The fertilizing ability of spermatozoa is preserved in the epididymis for up to 2-3 months. The spermatozoa that have reached the caudal epididymis have a high fertilizing capacity and can be released during ejaculation.
Anatomical and histological structure of the lymph nodes. What function do they perform
Morphologically, the lymphatic system is mainly an appendage of the cranial vena cava, and functionally complements the circulatory system. Their intermediary is tissue fluid, which originates from blood plasma, in the walls of blood capillaries. Nutrients from the tissue fluid enter the cells of the body, and metabolic products from the cells enter the tissue fluid. Tissue fluid partly goes back into the blood, and partly into the lymphatic capillaries and becomes blood plasma (and not just lymph).
The lymphatic system, unlike the circulatory system, performs:
) drainage function - removes excess fluid from all tissues and organs, from serous cavities, from the intershell spaces of the central nervous system, from the joints into the blood;
) resorbs from tissues colloidal solutions of protein substances that are not able to penetrate into the blood capillaries;
) from the intestine resorbs, in addition, fats and proteins;
) performs a protective function, which is expressed in the purification of tissue fluid from foreign particles, microorganisms and toxins;
) blood-forming function - lymphocytes develop in the lymph nodes, which subsequently enter the blood;
) antibodies are formed in the lymph nodes.
It is a fluid that fills the lymphatic vessels and lymph nodes. It consists of lymph plasma and formed elements. Lymph plasma is similar to blood plasma, but differs from it in that it contains part of the metabolic products of those organs from which lymph flows. The cellular elements of the lymph are mainly represented by lymphocytes entering the lymphatic vessels from the lymph nodes, therefore, the vascular lymph to the lymph nodes consists mainly of lymph plasma. Fat is absorbed into the lymph flowing from the intestines, so this lymph takes on a milky appearance and is called hilus - and the lymphatic vessels of the intestine are called lacteal vessels.
The amount of lymph varies depending on various causes, but in general, about 2/3 of the body's weight falls on its fluids, mainly blood (5-10%) and lymph (55-60%), including "tissue fluid" and bound water. In a dog, lymph is excreted through the thoracic duct in an amount of up to 20-25% of body weight per day.
b) Lymphatic vessels and ducts
Lymphatic vessels are divided into lymphatic capillaries, intraorganic and extraorganic lymphatic vessels and lymphatic ducts.
Lymphatic capillaries are built from endothelium alone, nerve fibers are located outside the capillaries. They differ from blood capillaries:
b) the ability to easily stretch;
c) the presence of blind processes in the form of fingers of a glove.
The endothelium of the capillaries closely fuses with connective tissue fibers, therefore, with an increase in pressure in the tissues, the lymphatic capillaries not only do not compress, but, on the contrary, stretch, which is of great importance in pathological physiology.
Lymphatic capillaries accompany blood capillaries everywhere; they are absent where there are no blood capillaries, as well as in the central nervous system, in the lobules of the liver, in the spleen, in the cornea of the eyeball, in the lens and in the placenta. In some organs, lymphatic capillaries form superficial and deep networks, for example, in the skin, gastric mucosa, and serous membranes; in other organs they go in different directions, for example, in the muscles, in the ovary. In both cases, there are numerous anastomoses between the capillaries. The nature of the location of the lymphatic capillaries is extremely diverse.
Lymphatic vessels - have, in addition to the endothelium, additional membranes: intima, media and adventitia. The media is poorly developed, but contains smooth muscle cells. The diameter of the vessels is insignificant, the walls with a large number of paired valves are transparent, due to which the lymphatic vessels are difficult to distinguish on the preparations if they are not filled with lymph. Surrounding the blood vessels are perivascular lymphatic vessels.
Intraorganic lymphatic vessels are very small and form a large number of anastomoses. Extraorganic lymphatic vessels are somewhat larger. They are divided into superficial, or subcutaneous, and deep. The subcutaneous lymphatic vessels run radially towards the centrally located lymph nodes. Deep lymphatic vessels pass in neurovascular bundles. As a rule, lymphatic vessels flow into regional (regional) lymph nodes located in certain places of the body.
The main lymphatic vessels include the lymphatic thoracic duct, which carries lymph out of the body; right lymphatic trunk - collecting lymph from the right cranial quarter of the body: tracheal, lumbar and intestinal ducts.
Lymphatic vessels have their vessels from networks of blood capillaries, and arteries and veins are laid in the walls of large lymphatic vessels. The lymphatic vessels are innervated by sympathetic nerves.
c) Lymph nodes
The lymph node is a regional organ of formed reticular tissue, located along the afferent (afferent) lymphatic vessels that carry lymph from certain organs or parts of the body. Lymph nodes, with the participation of reticuloendothelial and white blood cells, perform the function of mechanical and at the same time biological filters and regulate the flow of lymph in them. Foreign substances trapped in the lymph are retained in the lymph nodes: coal particles, cell fragments, microorganisms and their toxins; lymphocytes multiply (blood-forming function). Lymph nodes also perform a protective function, produce antibodies.
In the lymph nodes, the parenchyma is considered - from the follicles in its cortical zone, with follicular strands in its brain zone: lymphatic sinuses - marginal and central, connective tissue skeleton - from the capsule and trabeculae. The skeleton contains, in addition to connective tissue, elastic and smooth muscle fibers. Blood vessels and sympathetic motor and sensory nerves go to the parenchyma and to the elements of the skeleton. Follicles and follicular strands are formed by compacted reticular tissue. In the follicles there are non-permanent centers of cell reproduction. The marginal sinus extends into the cortical zone of the lymphatic; it separates the capsule from the follicles, concentrating on the periphery of the node. The central sinuses are located between intertwining trabeculae and follicular strands that form the brain zone of the node. The walls of the sinuses are lined with endothelium, which passes into the endothelium of the lymphatic vessels entering and exiting the node.
The entire lymph node is filled with lymphocytes, among which there are other cells (lymphoblasts, macrophages and plasma cells). Sometimes a large number of red blood cells appear in the sinuses. Such lymph nodes turn red and are called red lymph nodes or hemolymph nodes.
The shape of the lymph nodes is bean-shaped, with a slight depression - the gate of the node. The efferent lymphatic vessels - and veins - enter through these gates, arteries and nerves enter. Bringing lymphatic vessels - enter the lymph node on its entire surface. There are more afferent vessels than efferent ones, but the latter are larger. In pigs, on the other hand, the afferent vessels enter through the hilum of the node, and the efferent ones exit on the entire surface of the lymph node. Accordingly, the internal structure is also changed: the follicular zone is located in the center of the lymph node, and the zone of follicular strands is on its periphery.
The size of the lymph nodes in different animals varies widely. The number of nodes reaches 60 in a dog, 190 in a pig, 300 in cattle and 8000 in a horse. The largest nodes are in cattle, the smallest in a horse, in which they usually form packages with up to several dozen nodes.
Lymph nodes, according to the origin of their “roots”, are divided into visceral (B), muscular (M) and skin (K), as well as muscular-visceral (MV) and musculoskeletal (CM). The visceral lymph nodes carry lymph from the internal organs on which they are located, for example, from the liver, stomach. Muscular lymph nodes lie in certain, most mobile parts of the body:
) at the border of the head and neck,
) at the entrance to the chest cavity,
) in the area of the joints: shoulder, elbow, sacroiliac, hip, knee, but not the same in different animals.
Cutaneous lymph nodes are present only in the region of the knee crease, and in other parts of the body there are skin-muscular-visceral (CMV) nodes.
The arteries of the lymph nodes pass through the hilum into the trabeculae. Capillaries form perifollicular networks around the follicles. Veins usually run in trabeculae separately from arteries. The nerves of the lymph nodes originate from the sympathetic. Interoreceptors look like free nerve endings and encapsulated Vater-Pacini bodies. Afferent nerve fibers originate from the spiral ganglia.
lymphatic spermatogenesis stomach
1. Vrakin V.F. Practicum on anatomy with the basics of histology and embryology of agricultural animals. - M .: "Koloss" 2009
2. Vrakin V.F., Sidorova M.V. Morphology of agricultural animals.-M.: "Agropromizdat", 2009 (Morphology of animals; Morphology and physiology of animals)
Klimov A., Akaevsky A. Anatomy of domestic animals. - Publishing House "Lan", 2008.
