The narrow, elongated part is called secretory. It contains cells that produce a variety of chemical elements.
The expanding part is the excretory duct, which is needed to deliver substances to the stomach. The surface of the stomach cavity is rough and has many hills and pits that are located in them. Such pits are called mouths. The stomach has four sections.
Features of the glands
For high-quality digestion of food, it requires careful preparation, which includes grinding into small pieces and processing with digestive juice. With the help of glands, juice is produced, which is saturated with various chemical elements. These elements promote the digestion process and prepare food to move through the duodenum.
The glands are located in the epithelial membrane, which represents a triple layer of epithelium, muscle cells and serous layer. The first couple of layers provide protection and motility, and the last (outer) layer provides shaping. The lifespan is from 4 to 6 days, after which they are replaced with new ones. The renewal process is regular and occurs thanks to the stem tissues located in the upper part of the glands.
Types of gastric glands
Experts distinguish the following types of gastric glands:
- own (fundic glands of the stomach), located on the bottom, as well as the body of the stomach;
- pyloric (secretory), located in the pyloric region and form a food bolus.
- cardiac, located in the cardiac part of the stomach.
Own glands
The gastric glands are the most numerous secretory organs of the stomach. There are about 35 million of them in the body. Each such gland occupies 100 mm of the stomach area. The total area of the fundic glands is incredible in size and can reach up to 4 m2.
One tube is 0.65 mm long and can reach 50 microns in diameter. Many of these glands are grouped in the dimples. The secretory organ has an isthmus, a neck, as well as a main part that has a body and a bottom. They are responsible for excretory processes, and the neck and isthmus remove secretions into the gastric cavity.
The gland itself has 5 types of glandular cells:
- Main exocrinocytes. They are located mainly on the bottom and body. Cell nuclei They have a round shape and are located in the cell center. The basal cell part has a pronounced synthetic apparatus and basophilia. The apical part is lined with microvilli. The diameter of the secretion granule reaches 1 micron.
These cells produce pepsinogen. When mixed with hydrochloric acid, it is degenerated into pepsin (a more active organic substance).
- Paring cells. They are located outside and adjacent to the basal parts of the mucous membranes or the main exocrinocytes. The sizes exceed the main cells and have an irregular circle shape. This type of cells is located one at a time and is most often found in the body or neck area.
The cell cytoplasm is extremely oxyphilic. Each cell contains from one to two round nuclei located in the center of the cytoplasm. Intracellular tubules with a large number of microvilli, small vesicles, and tubules form the tubuvesicular system, which is an important component in the process of transporting Cl ions. Cells are characterized by the presence of a large number of mitochondria. Parietal exocrinocytes produce H+ - ions, as well as chlorides necessary for the formation of hydrochloric acid.
- Mucous, cervical mucocytes. These cells come in two types. Cells of the same type are located in the body of their gland and have denser nuclei in the basal cell part. The apical part of such a cell is covered with a large number of oval and round granules. It also has several mitochondria, as well as the Golgi apparatus.
Other mucous cells are located only in the neck of their own glands. The nuclei of such endocrinocytes have a flattened, sometimes irregular, triangle shape and are located closer to the base of the endocrinocytes. Secretion granules are located in the apical part. The substance that the cervical cells produce is mucus. Compared to the superficial ones, the cervical ones are smaller in size and also have a low content of mucus droplets. The composition of the secretion is different from mucoid. Neck cells may often contain elements of mitosis. It is assumed that these are undifferentiated epithelial cells, which are considered the source of restoration of the secretory epithelium, as well as the gastric pits.
- Argyrophilic. These cells are also part of the gland and belong to the APUD system.
- Undifferentiated epithelial cells.
Pyloric glands
This species is located in the area where the stomach joins the duodenum and numbers about 3.5 million pieces. The pyloric gland has the following characteristics:
- sparser location on the surface;
- more branched;
- have a wide clearance;
- most do not have parietal cells.
The terminal section of such a secretion organ mainly has a cellular composition that resembles its own glands. The core is flattened and located closer to the base. A large number of dipeptidases are noted. The secretion that this gland produces has an alkaline reaction.
The mucous membrane in its structure of the bottom part has deeper pits, occupying more than half of the total thickness. At the exit, the shell has a pronounced fold in the shape of a ring. This pyloric sphincter appears due to the presence of a strong circular layer of the muscular layer and is designed to dose food entering the intestines.
Cardiac glands
The cardiac glands of the stomach are tubular in shape and have a very branched end section. Short excretory ducts line prism-shaped cells. The nucleus is flattened and located at the cell base. Secretory cells are similar to the pyloric cells of the stomach and the cardiac cells of the esophagus. In addition, they were found to contain dipeptidase.
How it works
The work process can be represented as follows. The aroma and visual component of food irritate the receptors located in the mouth. This process helps trigger gastric secretion.
The cardiac glands secrete mucus, which is designed to soften food and protect the stomach from self-digestion. Own glands begin the process of secreting hydrochloric acid, as well as enzymes necessary for digestion.
Food is dissolved and disinfected in hydrochloric acid, after which enzymes come into play to promote chemical processing. The highest intensity of production of gastric juice components is characterized by the first time of eating (it is for this reason that chewing gum is not recommended).
The largest amount of juice is observed in the second hour after the start of digestive processes. As food moves towards small intestine, the volume of gastric juice gradually decreases.
Factors that affect the functioning of the glands
Among the most common factors influencing the performance of the glands are the following:
- Consumption of food containing large amounts of protein (low-fat meat, dairy products, legumes) quickly leads to the launch of gastric secretion processes. With daily consumption of meat products, the acidity and digestive ability of gastric juice will significantly increase. Carbohydrates, which include sweets, flour products and cereals, are considered the weakest secretion stimulants.
- Stress can contribute to the active functioning of the glands. It is for this reason that doctors recommend eating normally even during periods of severe anxiety in order to avoid “stress” ulcers.
- A person’s negative emotional background (fear, melancholy, depression) significantly reduces the secretion of gastric juice. For this reason, you should never “eat up” melancholy or depression, as it can cause significant harm to your health. In such cases, it is better to eat meat, since it is more difficult to digest and helps to “invigorate” the body.
Thus, the small tubes inside the stomach are designed to perform very important task for the life of the body. To make their work easier, you need to eat right, eat less sweets and more healthy foods.
The structure of the stomach glands
The main function of the gastrointestinal tract - digestion of food - is carried out by the glands of the stomach. These tubes are responsible for secreting many chemicals for gastric juices. There are several types of secretors. In addition to the external glandular centers, there are internal endocrine centers that produce a special external secretion. If at least one group fails, serious pathologies develop, so it is important to know their purpose and features.
Peculiarities
In order for food coming from the esophagus to be well digested, it must be carefully prepared, ground into small particles and treated with digestive juice. This is what the stomach glands are for. These are formations in the shell of the organ, which are tubes. They consist of a narrow (secretory part) and a wide (excretory) section. Glandular tissues secrete juice, consisting of many chemical elements necessary for digestion and preparation of food for entry into the duodenum.
Each part of the organ has its own glands:
- primary processing of food coming from the esophagus to the cardiac zone;
- the main load that makes up the foundation area;
- secretory - cells that form neutral chyme (bolus of food) for entry into the intestine from the pyloric zone.
The glands are located in the epithelial membrane, which consists of a complex triple layer, including an epithelial, muscular, and serous layer. The first two are designed to provide protection and motor skills, the last is molding, external. The structure of the mucosa is distinguished by relief with folds and pits that protect the glands from the aggression of gastric contents. There are secretors that synthesize hydrochloric acid to provide the necessary acidity in the stomach. The glands of the stomach live only 4-6 days, after which they are replaced by new ones. Updating secretors and epithelial membrane occurs regularly due to stem tissues localized in the upper part of the glands.
Types of gastric glands
Pyloric
These centers are located at the junction of the stomach and the small intestine. The structure of glandular cells is branched with a large number terminal tubules and wide lumens. The pyloric glands have endocrine and mucous secretors. Both components play a specific role: the endocrine centers do not secrete gastric juice, but control the functioning of the gastrointestinal tract and other organs, and the accessory centers form mucus, which dilutes the digestive juice in order to partially neutralize the acid.
Cardiac
They are located at the entrance to the organ. Their structure is formed from endocrine tubes with epithelial ones. The task of the cardiac glands is the secretion of mucoid mucus with chlorides and bicarbonates, which is necessary to ensure the sliding of the food bolus. These mucous accessory secretors are also located at the bottom of the esophagus. They soften food as much as possible in preparation for digestion.
Own
They are numerous and cover the entire body of the stomach, lining the bottom of the stomach. Fundic bodies are also called the own glands of the stomach. The tasks of these structures include the production of all components of gastric juice, in particular pepsin, the main digestive enzyme. The fundic structure includes mucous, parietal, main, and endocrine components.
For a long time chronic inflammation the stomach's own glands degenerate into cancerous ones.
Types of endocrine glands
The glands described above are exocrine, removing secretions to the outside. There are also no endocrine centers that produce secretions that go directly into the lymph and bloodstream. Based on the structure of gastric tissues, endocrine components are part of the exocrine glands. But their functions are strikingly different from the tasks of the parietal elements. Endocrine glands are numerous (most of all in the pyloric region) and produce the following substances for digestion and its regulation:
- gastrin, pepsinogen, synthesized to increase the digestive activity of the stomach, the mood hormone - enkephalin;
- somatostatin, which is secreted by D-elements to inhibit the synthesis of protein, gastrin and other main digestive elements;
- histamine - to stimulate the synthesis of hydrochloric acid (also affects blood vessels);
- melatonin - for daily regulation of the gastrointestinal tract;
- enkephalin - for pain relief;
- vasointestinal peptide - to stimulate the pancreas and dilate blood vessels;
- bombesin, produced by P-structures to increase the secretion of hydrogen chloride, gallbladder activity, and appetite production;
- enteroglucagon, produced by A-centers to control carbohydrate metabolism in the liver and inhibit gastric secretion;
- serotonin, motilin, stimulated by enterochromaffin secretory centers, for the production of enzymes, mucus, and activation of gastric motility.
Work of the stomach
The stomach is a complex reservoir for temporary storage of food before being delivered to the small intestine. The organ undergoes careful preparation of the food bolus for further movement through the gastrointestinal tract. The stomach releases some components that immediately enter the blood and lymph. Lumps of food are ground, partially broken down and enveloped in bicarbonate mucus for the unhindered, safe passage of food chyme into the intestines. Therefore, in this part digestive system partial mechanical and chemical treatment food.
The muscle layer of the stomach is responsible for mechanical splitting. Chemical preparation is carried out by gastric juice, which consists of enzymes and hydrochloric acid. These digestive components are secreted by the parietal glands of the stomach. The composition of the juice is aggressive, so it can dissolve even small cloves in a week. But without the special protective mucus produced by other glandular centers, the acid would corrode the stomach. Special protective mechanisms always work, and their strengthening occurs with a sharp jump in acidity, provoked by rough, heavy or unhealthy foods, alcohol or other factors. Failure of at least one mechanism leads to serious disorders in the mucous membrane, which will affect not only the stomach itself, but also the entire gastrointestinal tract.
The glandular centers of the stomach are responsible for special protective mechanisms, which form:
- insoluble mucus, which contains the inner part of the gastric walls to create a barrier against the penetration of digestive juice into the tissues of the organ;
- mucous-alkaline layer, localized in the submucosal layer, with the alkali concentration equal to the acid content in the gastric juice;
- secret with special protective substances responsible for reducing the synthesis of hydrochloric acid, stimulating mucus production, optimizing blood flow, and accelerating cellular renewal.
Others defense mechanisms are:
- cellular regeneration every 3-6 days;
- intensive blood circulation;
- an antroduodenal brake that blocks the passage of food chyme into the DCP during a jump in acidity until the pH stabilizes.
It is extremely important to maintain optimal acidity in the stomach, since it is hydrochloric acid that provides the antimicrobial effect, the breakdown of food proteins, and regulates the activity of the organ. During the day, the parietal glands in the stomach secrete about 2.5 liters of hydrogen chloride. The acidity level between meals is 1.6-2.0, after - 1.2-1.8. But if the balance of the protective and acid-forming functions is disturbed, the lining of the stomach becomes ulcerated.
What determines the functioning of the glands?
The causative agents for acid-forming parietal centers are protein food eg meat. With daily use it is maintained increased acidity, the stomach is working hard. High-carbohydrate foods have less effect on function. Carbohydrates help reduce acidity. But fatty foods are an intermediate option.
The active causative agent is stress, due to which an ulcer develops.
Therefore, if there is a long-term tense situation, it is recommended to eat more. No less strong feelings are melancholy, fear, depression, which, on the contrary, reduce gastric secretion. In this case, it is better not to eat these negative emotions with food, so as not to harm your health. But in case of prolonged depressive states, you should prefer meat as a snack, which will support digestive function.
Gastric glands, their types and functions
The stomach is the most important human organ. It is necessary to prepare incoming food for further absorption in the intestines. This work is impossible without a large number digestive enzymes which are produced by the glands of the stomach.
The inner shell of the organ has a rough appearance in appearance, because on its surface there is great amount glands designed to produce various chemical compounds that make up the digestive juice. Outwardly, they resemble long narrow cylinders with an extension at the end. Inside them there are secretory cells, and through the expanded excretory duct, the substances they produce necessary for the digestive process are delivered to the stomach cavity.
Features of digestion in the stomach
The stomach is a cavity organ, an expanded part of the digestive canal, into which food is periodically received at irregular intervals. food products, every time different composition, consistency and volume.
The process of processing incoming food begins with the oral cavity, here it undergoes mechanical grinding, then moves further along the esophagus, enters the stomach, where it undergoes further preparation for absorption by the body under the influence of acid and enzymes of gastric juice. The food mass acquires a liquid or porridge-like state and, mixed with the components of gastric juice, smoothly enters the small and then large intestine to complete the digestion process.
Briefly about the structure of the stomach
Average stomach size for an adult:
- lengthcm;
- widthcm;
- wall thickness approximately 3 cm;
- capacity about 3 liters.
The structure of the organ is conventionally divided into 4 sections:
- Cardiac - located in the upper sections, closer to the esophagus.
- The body is the main part of the organ, the most voluminous.
- The bottom is the lower part.
- Pyloric - located at the outlet, closer to the duodenum.
The mucous membrane is covered over the entire surface by glands; they synthesize important components for the digestion and assimilation of consumed food:
Most of them are excretory ducts enters the lumen of the organ and is a component of digestive juice, others are absorbed into the blood and participate in the general metabolic processes of the body.
Types of gastric glands
The glands of the stomach differ in location, the nature of the secretion produced and the method of its secretion.
Exocrine
Digestive secretions are released directly into the lumen of the organ cavity. Named according to their location:
Own
This type of gland is very numerous - up to 35 million; they are also called fundic bodies. They are located mainly in the body and fundus of the stomach and produce all the components of gastric juice, including pepsin, the main enzyme digestive process.
The gastric glands are divided into 3 types:
- main ones - large sizes, combined into large groups; needed for the synthesis of digestive enzymes;
- mucous membranes are small in size and produce protective mucus;
- Parietal cells of the stomach are large, single, and produce hydrochloric acid.
Parietal (parietal) cells occupy the outer part of the main or fundal bodies located on the bottom and body of the organ. Outwardly they look like pyramids with bases. Their function is the production of hydrochloric acid and internal Castle factor. The total number of parietal cells in the body of one person approaches a billion. The synthesis of hydrochloric acid is a very complex biochemical process, without which food digestion is impossible.
Parietal cells also synthesize the most important component - a glycoprotein that promotes the absorption of vitamin B12. ileum, without which erythroblasts cannot reach mature forms, the normal process of hematopoiesis suffers from this.
Pyloric
Concentrated closer to the transition of the stomach into duodenum, have a smaller number - up to 3.5 million, have a branched appearance with several wide terminal exits.
The pyloric glands of the stomach are divided into 2 types:
- Endogenous. This type of gland is not involved in the process of producing digestive juices. They produce substances that are absorbed immediately into the blood to participate in numerous reactions metabolic processes the stomach itself and other organs.
- The mucous glands are called mucocytes. They are responsible for the production of mucus, to protect the mucous membrane from the destructive effects of digestive juices, rich in aggressive components - hydrochloric acid and pepsin, and to soften the food mass, in order to facilitate its sliding into the intestines.
Cardiac
Located in the initial part of the stomach, close to the junction with the esophagus. Their number is relatively small - about 1.5 million. By appearance and secreted secretions of the gland are similar to pyloric ones. There are only 2 types:
- Endogenous.
- Mucous membranes, the main task of which is to soften the food bolus as much as possible and prepare it for the digestion process.
The cardiac glands, like the pyloric glands, do not participate in the digestion process.
Scheme of the glands
The startup of the glands can be schematically represented as follows.
- The smell, sight and irritation of food receptors in the oral cavity give a signal to the beginning of the production of gastric secretions and preparation of the organ for food processing.
- In the cardiac region, the production of mucus begins, protecting the mucous membrane from self-digestion and softening the food mass, which makes it more accessible for further stages of processing.
- Own (fundic) bodies begin to produce digestive enzymes and hydrochloric acid. The acid, in turn, transforms foods into a semi-liquid state and disinfects them, and enzymes begin to chemically break down proteins, fats and carbohydrates to the molecular level, preparing them for further absorption in the intestines.
The most active production of all components of digestive juice (hydrochloric acid, enzymes and mucus) occurs at the initial stage of food intake, reaches a maximum in the second hour of the digestive process and persists until the food mass passes into the intestines. After the stomach is emptied of food mass, digestive juices stop being produced.
Endocrine glands
The gastric glands described above are exocrine, that is, the secretion they produce enters the stomach cavity. But among the digestive glands there is also a group of endocrine glands, which do not take part in the process of digesting food, and the substances produced by them enter without gastrointestinal tract, directly into the blood or lymph and are needed to stimulate or inhibit the functions of various organs and systems.
Endocrine glands produce:
- Gastrin is needed to stimulate the activity of the stomach.
- Somatostatin slows it down.
- Melatonin – controls the daily cycle of the digestive tract.
- Histamine – starts the process of accumulation of hydrochloric acid and regulates the function of the vascular system of the gastrointestinal tract.
- Enkephalin - has an analgesic effect.
- Vasointerstitial peptide - has a dual effect: dilates blood vessels and also activates the activity of the pancreas.
- Bombesin - stimulates the production of hydrochloric acid, controls the function of the gallbladder.
Correct and efficient functioning of the gastric glands is very important for the functioning of the entire human body. For their coordinated work you need little - just follow the rules of a healthy diet.
CELLS OF THE STOMACH'S OWN GLAND
The pictures below show the gastric pit. A gastric pit (GD) is a groove or funnel-shaped invagination of the surface of the epithelium (E).
The superficial epithelium consists of tall prismatic mucous cells (SCs) lying on a common basement membrane (BM) with the proper gastric glands (PGGs), which open and are visible deep in the dimple (see arrows). The basement membrane is often crossed by lymphocytes (L), penetrating from the lamina propria (LP) into the epithelium. In addition to lymphocytes, the lamina propria contains fibroblasts and fibrocytes (F), macrophages (Ma), plasma cells (PC) and a well-developed capillary network (Cap).
The superficial mucous cell, marked with an arrow, is shown at high magnification in Fig. 2.
To adjust the scale of the image of the cells in relation to the thickness of the entire gastric mucosa, the native glands are cut off below their necks. The cervical mucous cell (CMC), marked with an arrow, is shown at high magnification in Fig. 3.
On sections of glands, one can distinguish parietal cells (PCs), protruding above the surface of the glands, and constantly rearranging chief cells (GCs). The capillary network (Cap) around one of the glands is also depicted.
PRISMATIC MUCOUS CELLS OF THE STOMACH
Rice. 2. Prismatic mucous cells (MCs) are 20 to 40 nm in height, have an elliptical, basally located nucleus (N) with a prominent nucleolus, rich in heterochromatin. The cytoplasm contains rod-shaped mitochondria (M), a well-developed Golgi complex (G), centrioles, flattened granular cisterns endoplasmic reticulum, free lysosomes and varying amounts of free ribosomes. In the apical part of the cell there are many osmiophilic PAS-positive, single-layer membrane-bound mucus droplets (MSD), which are synthesized in the Golgi complex. Vesicles containing glycosaminoglycans probably leave the cell body by diffusion; in the lumen of the gastric pit, mucigen vesicles are converted into acid-resistant mucus, which lubricates and protects the epithelium of the surface of the stomach from the digestive action of gastric juice. The apical surface of the cell contains several short microvilli covered with glycocalyx (Gk). The basal pole of the cell lies on the basement membrane (BM).
Prismatic mucous cells are connected to each other by well-developed junctional complexes (J), numerous lateral interdigitations and small desmosomes. Deeper in the dimple, the superficial mucous cells continue into the cervical mucous cells. The lifespan of mucous cells is about 3 days.
CERVICAL MUCOUS CELLS OF THE STOMACH
Rice. 3. Cervical mucous cells (CMCs) are concentrated in the neck area of the stomach’s own glands. These cells are pyramidal or pear-shaped and have an elliptical nucleus (N) with a prominent nucleolus. The cytoplasm contains rod-shaped mitochondria (M), a well-developed supranuclear Golgi complex (G), a small number of short cisternae of the granular endoplasmic reticulum, occasional lysosomes and a certain number of free ribosomes. The supranuclear part of the cell is occupied by large PAS-positive, moderately osmiophilic, secretory granules (SGs) surrounded by single-layer membranes, which contain glycosaminoglycans. The surface of the mucous cervical cells, facing the dimple cavity, bears short microvilli covered with glycocalyx (Gk). On the lateral surface there is a good lateral ridge-like interdigitations and junctional complexes are visible (K).The basal surface of the cell is adjacent to the basement membrane (BM).
Cervical mucous cells can also be found in the deep sections of the native gastric glands; they are also present in the cardiac and pyloric parts of the organ. The function of cervical mucous cells is still unknown. According to some scientists, they are undifferentiated replacement cells for superficial mucosal cells or progenitor cells for parietal and chief cells.
In Fig. Figure 1 to the left of the text shows the lower part of the body of the gastric gland (SG), cut transversely and longitudinally. In this case, a relatively constant zigzag direction of the gland cavity becomes visible. This is due to the mutual position of parietal cells (PCs) with chief cells (GCs). At the base of the gland the cavity is usually straight.
The glandular epithelium is located on the basement membrane, which is removed in the cross section. A dense capillary network (Cap), closely surrounding the gland, is located lateral to the basement membrane. Pericytes (P) covering the capillaries are easily visible.
Three types of cells can be isolated in the body and base of the gastric gland. Starting from the top, these cells are marked with arrows and are shown on the right side in Fig. 2-4 at high magnification.
MAIN CELLS
Rice. 2. Chief cells (CH) are basophilic, from cubic to low prismatic in shape, localized in the lower third or lower half of the gland. The nucleus (N) is spherical, with a pronounced nucleolus, located in the basal part of the cell. The apical plasmalemma, covered with glycocalyx (Gk), forms short microvilli. Chief cells connect to neighboring cells using junctional complexes (K). The cytoplasm contains mitochondria, developed ergastoplasm (Ep) and a well-defined supranuclear Golgi complex (G).
Zymogen granules (ZGs) originate from the Golgi complex and then transform into mature secretory granules (SGs), accumulating at the apical pole of the cell. Then their contents, by fusion of the granule membranes with the apical plasmalemma, are released by exocytosis into the gland cavity. Chief cells produce pepsinogen, which is a precursor to the proteolytic enzyme pepsin.
PARIETAL CELLS
Rice. 3. Parietal cells (PCs) - large pyramidal or spherical cells with bases protruding from outer surface body of the own gastric gland. Sometimes parietal cells contain many elliptical large mitochondria (M) with densely packed cristae, a Golgi complex, several short cisternae of the granular endoplasmic reticulum, a small number of tubules of the agranular endoplasmic reticulum, lysosomes and a few free ribosomes. Branched intracellular secretory tubules (ISCs) with a diameter of 1-2 nm begin as invaginations from the apical surface of the cell, surround the nucleus (N) and almost reach the basement membrane (BM) with its branches.
Many microvilli (MV) protrude into the tubules. A well-developed system of plasmalemmal invaginations forms a network of tubular-vascular profiles (T) with contents in the apical cytoplasm and around the tubules.
Severe acidophilia of parietal cells is the result of the accumulation of numerous mitochondria and smooth membranes. Parietal cells are connected by junctional complexes (J) and desmosomes to neighboring cells.
Parietal cells synthesize hydrochloric acid by a mechanism that is not fully understood. Most likely, tubular-vascular profiles actively transport chloride ions through the cell. Hydrogen ions released in the reaction of carbonic acid production and catalyzed by carbonic anhydride cross the plasmalemma by active transport, and then, together with chlorine ions, form 0.1 N. HCI.
Parietal cells produce gastric intrinsic factor, which is a glycoprotein responsible for the absorption of B12 in the small intestine. Erythroblasts cannot differentiate into mature forms without vitamin B12.
ENDOCRINE (ENTEROENDOCRINE, ENTEROCHROMAFFIN) CELLS
Rice. 4. Endocrine, enteroendocrine or enterochromaffin cells (EC) are localized at the base of the gastric glands. The cell body may have a triangular or polygonal nucleus (N), located at the apical pole of the cell. This cell pole rarely reaches the gland cavity. The cytoplasm contains small mitochondria, several short cisterns of the granular endoplasmic reticulum and the infranuclear Golgi complex, from which osmiophilic secretory granules (SG) with a diameter of 150-450 nm are separated. The granules are released by exocytosis from the cell body (arrow) to the capillaries. After crossing the basement membrane (BM), the granules become invisible. The granules produce argentaffin chromaffin reactions simultaneously, hence the term enterochromaffin cells. Endocrine cells are classified as APUD cells.
There are several classes of endocrine cells, with slight differences between them. NK cells produce the hormone serotonin, ECL cells produce histamine, G cells produce gastrin, which stimulates the production of HCl by parietal cells.
A. GASTRIN
b. PEPSINOGEN
V. MUCOID SECRET
g. hydrochloric acid
Question 84.
PRIMARY CLEAVATION IN THE ORAL CAVITY
b. CARBOHYDRATES
V. BELKOV
city of VITAMINS
Question 85.
PROMOTION OF FOOD FROM THE CARDIAL SECTION OF THE STOMACH TO THE PYLORIC
PROMOTE STOMACH MOVEMENTS
A. TONIC
b. ANTIPERISTALTIC
V. PERISTALTIC
d. SYSTOLIC
Question 86.
NEGATIVE NITROGEN BALANCE IS CHARACTERISTIC WHEN
A. FEVERY CONDITIONS
b. PROTEIN FASTING
V. PREGNANCY
Question 87.
ABSORBED IN AN UNCHANGED FORM INTO THE BLOOD
b. CARBOHYDRATES
V. VITAMINS
d. MINERAL SUBSTANCES
Question 88.
AREA OF PROJECTION OF THE SMALL INTESTINE ON THE ABDOMINAL WALL:
A. EPIGASTRAL
b. UMBILICAL
V. RIGHT INGUINAL
LEFT INGUINAL
Question 89.
CARBOHYDRATES ARE BREAKDOWN BY ENZYMES
A. AMYLOLYTIC
b. PROTEOLYTIC
V. ENTEROLITHIC
d. LIPOLYTIC
Question 90.
THE BASE OF TRUE SATURATION IS THE INFLUENCE ON THE SATURATION CENTER
A. METABOLISM PRODUCTS ABSORBED INTO THE BLOOD
b. C-RECEPTORS OF A STRETCHED STOMACH
V. "HUNGRY" FOR BLOOD
"HUNGRY" STOMACH MOVEMENTS
Question 91.
PRODUCTS OF CARBOHYDRATES BREAKDOWN:
A. ENZYMES
b. MONOSACHARIDES
V. GLYCERIN AND FATTY ACIDS
AMINO ACIDS
Question 92.
VOMITING OCCURS DURING STOMACH MOVEMENTS
A. PERISTALTIC
b. TONIC
V. SYSTOLIC
d. ANTIPERISTALTIC
Question 93.
THE DAILY REQUIREMENT OF A MATURE AGE PERSON FOR PROTEIN IS
A. 15 MG/KG WEIGHT
Question 94.
FUNCTION OF CHYMOSIN (RENNIN):
A. STIMULATION OF BILE SECTION
b. CURLDING MILK
V. PROTECTIVE
SYNTHESIS OF GROUP B VITAMINS
Question 95.
THE LIVER IS SUPPLIED WITH BLOOD
A. ONLY FROM THE ARTERIAL BED
b. ONLY FROM THE VENOUS BED
V. FROM ARTERIAL AND VENOUS - TOGETHER
Question 96.
AREA OF PROJECTION OF THE CECUM ON THE ANTERIOR ABDOMINAL WALL
A. RIGHT INGUINAL
b. LEFT SIDE
V. UMBILICAL
d. RIGHT ILIAC
Question 97.
ACCESSORY CELLS OF THE GLANDS OF THE STOMACH PRODUCE
b. GASTRIN
V. HYDROCHLORIC ACID
PEPSINOGEN
Question 98.
THE EXCENTRATOR DUCT OF THE SUBMANDIBLIAR GLAND OPENS
A. ON THE BUCHAL MUCOSA AT THE LEVEL OF THE SECOND SMALL MORTAR TOOTH
b. ON THE BUCHAL MUCOSA AT THE LEVEL OF THE SECOND MARK TOOTH
V. ON THE ORAL MUCOSA IN THE AREA OF THE GLAND
d. UNDER THE LOWER JAW
Question 99.
THE MUCOSA OF THE ORAL VESTIUM FORMS
A. Frenulum of the lower lip
b. Frenulum of the upper lip
V. FRINGED PLATES
frenulum of the tongue
Question 100.
ANTI-HAEMORAGIC VITAMIN
Question 101.
THE STOMACH DOES NOT HAVE A STOMACH IN ITS STRUCTURE
A. PYLORIC DEPARTMENT
b. TOP
V. CARDIAC DEPARTMENT
GREAT CURVATURE
Question 102.
THE GLANDS OF THE STOMACH ARE CONSISTED OF
A. MAIN CELLS
b. MUCOID CELLS
V. GOBLET CELLS
d. PARLING CELLS
Question 103.
THE FOLLOWING FUNCTIONS ARE NOT CHARACTERISTIC FOR THE LIVER:
A. UREA FORMATION
b. EXCRETORY FUNCTION
V. PARTICIPATING IN FAT METABOLISM
d. PROTECTIVE FUNCTION
d. BARRIER FUNCTION
e. PARTICIPATION IN PROTEIN METABOLISM
and. PARTICIPATION IN CARBOHYDRATE METABOLISM
Question 104.
PROTEOLYTIC ENZYMES BREAK DOWN
V. CARBOHYDRATES
FIBER
Question 105.
MOVEMENTS OF THE LARGE INTESTINE:
A. SYSTOLIC
b. PENDULUM-SHAPED
V. MASS REDUCTIONS
d. PERISTALTIC
Question 106.
VITAMIN "D" IS NOT USED
A. FOR FORMING THE FETAL SKELETON
b. FOR GROWTH OF BONE TISSUE
V. FOR BIOSYNTHESIS OF BLOOD PROTEINS
d. TO PROVIDE VISUAL FUNCTION
Question 107.
GASTRIC JUICE ENZYMES:
A. CHYMOTRYPSIN
b. PEPSIN
V. TRYPSIN
KHIMOZIN (RENNIN)
Question 108.
PYLORICAL SFINCTER SEPARATES
A. DUODENAL FROM SMALL
b. STOMACH FROM ESOPHAGUS
V. STOMACH FROM THE DUODENUM
SMALL INTESTINE FROM LARGE
Question 109.
WHICH SUBSTANCE IS ABSORBED IN THE STOMACH
A. GLUCOSE
b. GLYCEROL
V. AMINO ACIDS
ALCOHOL
Question 110.
THE FRONT WALL OF THE ORAL CAVITY PRESENTUM IS FORMED
b. SUPRAHYGLOUS MUSCLES
V. HARD AND SOFT PALATE
Question 111.
THE EXCRETORY DUCT OF THE HYPOGLUSAL SALIVARY GLAND OPENS
A. ON THE BUCHAL MUCOSA AT THE LEVEL OF THE SECOND MARK TOOTH
b. ON THE BUCHAL MUCOSA AT THE LEVEL OF THE SECOND SMALL MORTAR TOOTH
V. UNDER THE TONGUE
d. ON THE ORAL MUCOSA IN THE AREA OF THE GLAND
Question 112.
FOOD OF ANIMAL ORIGIN PREVAILS
V. CARBOHYDRATES
Question 113.
BILE REACTION
A. ALKALINE
b. SOUR
V. NEUTRAL
Question 114.
THE PANCREAS HAS
A. HEAD
V. CHANGES
d. PARTITION
Question 115.
GASTRIXIN GASTRIC JUICE:
A. STIMULATES BILE SECRETION
b. EMULSIFIES FATS
V. BREAKS PROTEINS
d. CONVERTS PEPSINOGEN TO PEPSIN
Question 116.
THE PROCESS OF GLYCOGENESIS IS:
A. GLYCOGEN TRANSFER
b. GLYCOGEN SYNTHESIS
V. GLYCOGEN BREAKDOWN
Question 117.
PROTEIN BREAKDOWN PRODUCTS:
A. GLYCERIN AND FATTY ACIDS
b. ENZYMES
V. AMINO ACIDS
d. MONOSACHARIDES
The gastric cavity is one of the important organs. This is where food digestion begins. When food enters the mouth, gastric juice begins to be actively produced. When it enters the stomach, it is susceptible to the action of hydrochloric acid and enzymes. This phenomenon occurs as a result of the activity of the digestive glands of the stomach.
The stomach is part of the digestive system. In appearance it resembles an oblong cavity ball. When the next portion of food arrives, gastric juice begins to actively secrete in it. It consists of different substances and has an unusual consistency or volume.
First, food enters the mouth, where it is processed mechanically. Then it passes through the esophagus into the stomach. In this organ, food is prepared for further absorption by the body under the influence of acid and enzymes. The food lump takes on a liquefied or mushy state. It gradually passes into the small intestine and then into the large intestine.
Appearance of the stomach
Each organism is individual. This also applies to the condition internal organs. Their sizes may vary, but there is a certain norm.
- The length of the stomach is between 16-18 centimeters.
- The width can vary from 12 to 15 centimeters.
- The wall thickness is 2-3 centimeters.
- The capacity reaches up to 3 liters for an adult with a full stomach. On an empty stomach, its volume does not exceed 1 liter. IN childhood the organ is much smaller.
The gastric cavity is divided into several sections:
- cardiac region. Located at the top closer to the esophagus;
- body of the stomach. It is the main part of the organ. It is the largest in size and volume;
- bottom. This is the lower part of the organ;
- pyloric section. It is located at the outlet and connects to the small intestine.
The epithelium of the stomach is covered with glands. Main function is considered to be the synthesis of important components that help in the digestion and absorption of food.
This list includes:
- hydrochloric acid;
- pepsin;
- slime;
- gastrin and other types of enzymes.
Most of it is excreted through the ducts and enters the lumen of the organ. If you combine them together, you get digestive juice, which helps in metabolic processes.
Classification of gastric glands
The glands of the stomach differ in location, the nature of the secreted contents and the method of excretion. In medicine, there is a certain classification of glands:
- own or fundic glands of the stomach. They are located at the bottom and in the body of the stomach;
- pyloric or secretory glands. They are located in the pyloric section of the stomach. Responsible for the formation of the food bolus;
- cardiac glands. Located in the cardiac part of the organ.
Each of them performs its own functions.
Glands of their own type
These are the most common glands. There are about 35 million pieces in the stomach. Each gland covers an area of 100 millimeters. If you calculate the total area, it reaches enormous sizes and reaches 4 square meters.
Own glands are usually divided into 5 types.
- Basic exocrinocytes. They are located on the bottom and in the body of the stomach. Cellular structures have a round shape. It has a pronounced synthetic apparatus and basophilia. The apical region is covered with microvilli. The diameter of one granule is 1 micromillimeter. This type of cellular structure is responsible for the production of pepsinogen. When mixed with hydrochloric acid, pepsin is formed.
- Parietal cell structures. Located outside. They come into contact with the basal parts of the mucous membranes or main exocrinocytes. Have big size and the wrong kind. This type of cell structures are located singly. They can be found in the body and neck of the stomach.
- Mucous or cervical mucocytes. Such cells are divided into two types. One of them is located in the body of the gland and has dense nuclei in the basal area. The apical part is covered with a large number of oval and round granules. These cells also contain mitochondria and the Golgi apparatus. If we talk about other cellular structures, they are located in the neck of their own glands. Their nuclei are flattened. In rare cases, they take on an irregular shape and are located at the base of the endocrinocytes.
- Argyrophilic cells. They are part of the ferrous composition and belong to the APUD system.
- Undifferentiated epithelial cells.
Own glands are responsible for the synthesis of hydrochloric acid. They also produce an important component in the form of a glycoprotein. It promotes the absorption of vitamin B12 in the ileum.
Pyloric glands
This type of gland is located in the area where the stomach joins with small intestine. There are about 3.5 million of them. The pyloric glands have several distinctive features as:
- rare location on the surface;
- the presence of greater branching;
- expanded lumen;
- absence of parental cellular structures.
Pyloric glands are divided into two main types.
- Endogenous. Cells do not participate in the process of producing digestive juice. But they are capable of producing substances that are instantly absorbed into the blood and are responsible for the reactions of the organ itself.
- Mucocytes. They are responsible for the production of mucus. This process helps protect the lining from the adverse effects of gastric juice, hydrochloric acid and pepsin. These components soften the food mass and facilitate its sliding through the intestinal canal.
The terminal section has a cellular composition that in appearance resembles its own glands. The core has a flattened shape and is located closer to the base. Includes a large number of dipeptidases. The secretion produced by the gland is characterized by an alkaline environment.
The mucous membrane is dotted with deep pits. At the exit it has a pronounced fold in the form of a ring. This pyloric sphincter is formed as a result of a strong circular layer in the muscular layer. It helps dose food and send it into the intestinal canal.
Cardiac glands
Located at the beginning of the organ. They are located close to the junction with the esophagus. The total number is 1.5 million. In appearance and secretion they are similar to pyloric ones. Divided into 2 main types:
- endogenous cells;
- mucous cells. They are responsible for softening the food bolus and the preparatory process before digestion.
Such glands do not take part in the digestive process.
All three types of glands belong to the exocrine group. They are responsible for the production of secretions and their entry into the gastric cavity.
Endocrine glands
There is another category of glands, which are called endocrine. They do not take part in the digestion of food. But they have the ability to produce substances that enter directly into the blood and lymph. They are needed to stimulate or inhibit the functionality of organs and systems.
Endocrine glands can secrete:
- gastrin. Necessary for stimulating the activity of the stomach;
- somatostatin. Responsible for inhibiting the organ;
- melatonin. They are responsible for the daily cycle of the digestive organs;
- histamine. Thanks to them, the process of accumulation of hydrochloric acid is started. They also regulate the functionality of the vascular system in the gastrointestinal tract;
- enkephalin. Exhibit an analgesic effect;
- vasointerstitial peptides. They exhibit a double effect in the form of vasodilation and activation of the pancreas;
- bombesin. The processes of hydrochloric acid production are launched, and the functionality of the gallbladder is controlled.
Endocrine glands influence the development of the stomach and also play an important role in the functioning of the stomach.
Scheme of the gastric glands
Scientists have conducted many studies on the functionality of the stomach. And to determine his condition, they began to perform histology. This procedure involves taking material and examining it under a microscope.
Thanks to histological data, it was possible to imagine how the glands in the organ work.
- The smell, sight and taste of food triggers food receptors in the mouth. They are responsible for sending a signal that it is time to form gastric juice and prepare the organs for digesting foods.
- Mucus production begins in the cardiac region. It protects the epithelium from self-digestion and also softens the food bolus.
- The intrinsic or fundic cellular structures are involved in the production of digestive enzymes and hydrochloric acid. Acid allows you to liquefy foods and also disinfects them. After this, enzymes are taken over to chemically break down proteins, fats and carbohydrates into a molecular state.
- Active production of all substances occurs on initial stage eating. The maximum is reached only in the second hour of the digestive process. Then all this is stored until the food bolus passes into the intestinal canal. After the stomach is empty, the production of components stops.
If the stomach suffers, histology will indicate the presence of problems. The most common factors include eating junk food and chewing gum, overeating, stressful situations, depressive state. All this can lead to the development of serious problems in the digestive tract.
To distinguish the functionality of the glands, it is worth knowing the structure of the stomach. If problems arise, the doctor prescribes additional medications that reduce excessive secretion and also create a protective film that covers the walls and mucous membrane of the organ.
1) pepsinogen and renin
4) serotonin and endorphins
199. Parietal cells of the fundic glands of the stomach produce:
1) pepsinogen and renin
3) components of hydrochloric acid and internal antianemic factor
4) serotonin and endorphins
200. Outline the sequence of stages in the history of the development of physiology?
1) abstract-theoretical;
2) active search;
3) accumulation of facts;
4) experimental modeling.
201. Arrange the structural components of the body starting with the simplest?
2) cell;
3) system;
5) organ system
202. Reflexes that arise to maintain a posture in motion are called..
1) unadapted to the perception of a given stimulus;
2) adapted to the perception of a given stimulus.
204. Distribute in order the laws of reaction of body structures to the action of stimuli?
1) increase in the strength of the pathogen;
2) time;
3) direct current action;
4) “all or nothing”;
205. What phases does the peak of the action potential have?
1) reversion;
2) rapid depolarization;
3) repolarization;
206. In what sequence does a nerve impulse pass through a synapse?
1) synaptic;
2) postsynaptic membrane;
3) presynaptic membrane.
207. What inhibitory mediators are released from nerve endings in 1) the central nervous system; 2) intestines, bronchi; 3) sphincter Bladder, heart pacemaker?
1) gamma-aminobutyric acid;
2) norepinephrine;
3) acetylcholine.
208. Establish the correct sequence of elements of the conduction system of the heart?
1) sinus node;
2) bundle of His;
3) Purkinje fibers;
4) atrioventricular node.
209. Indicate the sequence of options for possible maintenance of the general acid-base balance of the body by the kidneys?
210. What is the duration of the change in the membrane potential of nerve cells of vertebrates?
1) 0.2...0.3 ms;
3) 0.1...0.5 ms;
4) 0.4...2 ms;
5) 0.5...3 ms.
211. When superthreshold additional stimulation is applied to the heart muscle in the middle or end of diastole,...
2) extrasystole;
3) plateau phase;
4) compensatory pause.
212. Rank hexoses according to absorption rate?
1) glucose;
2) galactose;
3) fructose;
4) maltose.
213. Under the influence of what and during what period are esterogens synthesized?
1) follicle-stimulating hormone, during pregnancy;
2) somatotronin, during the period of active body growth;
3) prolactin, during lactation;
4) adrenocorticotropin, during puberty;
5) luteinizing hormone, during puberty.
214. What receptors perceive irritations from the internal environment of the body?
215. What polarity does the membrane potential of a nerve cell have at rest?
216. What is the half-life of hormones?
217. What is the content of prolactin in plasma during pregnancy of animals?
218. What structure of the ovary constantly performs endocrine function?
219. What is the volume in % of deposited blood in the body?
220. Which animals have a high content of myoglobin in their body?
221. How many platelets are contained in the blood of adult animals?
222. The set of electrical, mechanical, biochemical processes occurring in the heart during one contraction and relaxation is called...
223. A decrease in heart rate is called...
224. A substance capable of causing a specific immune response is called....
225. When superthreshold additional stimulation is applied to the heart muscle in the middle or end of diastole,...
226. The body’s ability to maintain genetic homeostasis is called...
227. What is the speed of impulse conduction in non-pulp nerve fibers?
228. A contraction in which the length of the fibers does not decrease, but their tension increases is called...
229. Within what limits does the concentration of thyroxine in the blood of animals fluctuate?
230. What is the average blood volume per body weight in animals?
231. What pH do blood and intercellular fluid have?
232. What is the average hemoglobin content in the blood of animals?
233. How long does it take on average for bleeding to stop in animals when small vessels are injured?
234. How many circulatory systems do mammals have?
235. After ventricular extrasystole comes...
236. How many standard leads are used to record ECG in animals?
237. Competent cell immune system consider...
238. What is the total number of chewing movements when chewing feed from a normal winter diet in cows per day?
239. What period occurs immediately after the action of a stimulus on excitable tissue?
240. At what frequency of muscle irritation can its serrated tetanic contraction be observed?
241. The time interval from the moment of stimulation of the receptors to the response of the executive organ is called...
242. What biologically active substances carry out the humoral regulation of body functions?
243. Which hormone is a functional antagonist of parathyroid hormone?
244. What is the main source of esterogens?
245. Which hormone is called the pregnancy hormone?
246. Where are blood plasma proteins formed?
247. The main organ of hematopoiesis is considered...
248. What does a lack of hemoglobin in the blood lead to?
249. What color does blood acquire when there is an excess of methemoglobin in it?
250. What blood cells play the main role in the formation of cellular and humoral immunity?
251. What enzyme causes the transition of fibrinogen to fibrin?
252. Which phase of the cardiac cycle is shortened during moderate tachycardia?
253. How many heart sounds are there in total and how many of them are heard?
254. The ability of the heart to contract under the influence of impulses arising in its conduction system is called...
255. How long does colostral immunity last?
256. Thanks to what substance are the alveoli constantly straightened and filled with air?
257. How many times is the frequency breathing movements lower heart rate?
258. How many interrelated phases of pancreatic juice secretion do you know?
259. What is the total amount of gastric juice secreted per day in cows?
260. Where is bile produced?
261. How much sweat can cattle produce per day?
262. The interval between divisions during oocyte maturation in animals during natural insemination is?
263. What is the highest level of acquired behavior called?
264. How many liters of gases per day can be formed in the rumen of a cow during the grazing period?
265. How much primary urine per 1 kg. live weight is formed in animals per day?
266. Which parts of the ear are classified as the perceptive apparatus?
267. Here is the formula for determining... VCO 2 \VO 2
268. What is the pH of the urine of herbivores on a normal diet?
269. Insufficient oxygen content in the tissues of the body is called...
270. The combination of hemoglobin with carbon dioxide is called...
271. The set of physiological processes that ensure bleeding stops is called....
272. When forming functional systems, maintaining homeostasis, blood provides the body … regulation.
The respiratory function of blood is ensured by... contained in red blood cells.
Blood supplies all cells of the body nutrients thanks to... features.
The destruction of the erythrocyte membrane and the release of hemoglobin into the plasma under the influence of various factors is called....
Blood plasma proteins create... pressure.
Muscles contain ......, which performs functions similar to hemoglobin.
Non-granular leukocytes capable of amoeboid movement and phagocytosis are called.....
Granular leukocytes with phagocytic activity and the ability to bind toxins are called......
280. In what form is iron found in 1) hemoglobin; 2) methemoglobin?
1) trivalent;
2) divalent.
281. Designate the levels of regulation of cardiac activity from the lowest to the highest?
1) intracardial;
2) extracardiac;
3) reflex;
4) humoral;
5) systemic.
282. Designate the sequence of blood movement through the capillary network?
1) postcapillary sphincters;
3) metarteriols;
4) precapillary sphincters;
5) venules.
283. Indicate the correct sequence of air passage through the airways?
1) nasal cavity;
2) trachea;
3) bronchi;
4) bronchioles, alveoli;
284. Indicate the sequence of processes that ensure digestion in the body?
1) biological;
2) physical;
3) mechanical;
4) chemical;
5) enzymatic
285. The functional classification of vessels according to Folkov implies the following vessels according to the degree of remoteness
1) exchange vessels
2) capacitive vessels
3) resistive vessels
4) shock-absorbing vessels
5) shunt vessels
6) sphincter vessels
7) biological pump
286. In what sequence is starch broken down in an alkaline environment in animals whose saliva contains α-amylase and α-glucosidase?
1) maltose;
2) glucose;
4) starch.
287. The conduction system of the mammalian ear is presented in the following sequence
1) outer ear
2) ear canal
3) middle ear
4) cochlear perilymph
5) cochlear endolymph
288. After what period of time do the complex-reflex gastric and intestinal phases of gastric juice secretion begin?
289. What is the sequence of action of factors that ensure the transition of chyme from the stomach to the intestines?
2) activity of the pyloric sphincter;
1) systolic contractions of the antrum of the stomach;
3) the influence of gastrointestinal hormones.
290. The transmission mechanism of the middle ear consists of
1) anvil
2) hammer
3) stirrup
4) lenticular bone
291. Determine the sequence of the physical cardiac cycle?
1) diastole;
2) general pause;
3) systole.
292. The reflex arc consists of...
1) peripheral receptor;
3) afferent pathway;
4) groups of central neurons;
2) efferent pathway and
5) effector.
293. Establish the sequence of stages in the structure of respiration of higher animals?
3) pulmonary ventilation;
2) exchange of gases in the lungs;
1) exchange of gases between blood and tissue fluid, intracellular respiration.
294. Indicate the sequence of options for possible maintenance of the general acid-base balance of the body by the kidneys?
1) regulation of the level of HCO - 3 in plasma;
2) regeneration of HCO - 3 ions;
3) secretion of H + ions into the urine.
295. In what sequence does the egg move during the period of estrus and fertilization?
1) ovary;
3) funnel of the oviduct.
296. Indicate the correspondence of the occurring pancreatic changes in secretion after a decrease in the amount of HCl in the pancreatic juice?
1)increases;
2) decreases.
297. Indicate the correspondence, where are the humoral mechanisms of digestion regulation most represented?
1) oral cavity;
2) small intestine;
3) stomach;
4) large intestine.
298. Designate the sequence of amino acid absorption mechanisms, starting with the minimum?
2) filtering
3) simple diffusion;
4) active transport.
299. Indicate the correct match, where does fatigue develop first?
2) synapse;
300. Rank hexoses according to absorption rate.
1) glucose;
2) galactose;
3) fructose;
4) maltose.
301. Establish the sequence of phases of the sexual cycle?
1) luteal;
2) follicular.
302. In what sequence are physiological methods most often used by scientists?
1) experiments;
2) observation.
303. Tissues capable of transitioning into a state of excitation in response to a stimulus are called...
304. The anterior lobe of the pituitary gland synthesizes... hormone
305. A stimulating effect on protein metabolism has...
306. Indicate the sequence of options for possible maintenance of the general acid-base balance of the body by the kidneys?
1) regulation of the level of HCO - 3 in plasma;
2) regeneration of HCO - 3 ions;
3) secretion of H + ions into the urine.
307. An increase in membrane potential is called...
308. In the blood of a healthy man, the amount of hemoglobin is:
1) 130-160 g/l
2) 100 – 110 g/l
4) 170-200 g/l
In blood healthy woman the amount of hemoglobin is:
1) 160-180 g/l
2) 170-200 g/l
3) 120-140 g/l
4) 100-120 g/l
In blood healthy person neutrophils from total number leukocytes are:
The main function of red blood cells is:
1) transport of carbohydrates
2) participation in blood buffer reactions
3) transport of oxygen and carbon dioxide
4) participation in digestive processes
5) maintaining osmotic pressure
Leukocytes perform the following functions:
1) participation in immune reactions
2) transport of hormones
3) maintaining oncotic pressure of blood plasma
4) transport of carbon dioxide and oxygen
5) participation in the activation of acid-base balance
Neutrophils are involved in:
1) production of antibodies
2) Gaparin transport
3) phagocytosis and destruction of microorganisms
4) activation of lymphocytes
5) carbon dioxide transport
The function of eosinophils is:
1) transport of carbon dioxide and oxygen
2) detoxification for allergic reactions
3) production of antibodies
4) maintaining osmotic pressure
5) maintaining the ionic composition of the blood
During the formation of functional systems that maintain homeostasis, blood provides regulation in the body:
1) nervous
2) reflex
3) humoral
4) local
5) behavioral
Blood function due to the presence of antibodies in it and the phagocytic activity of leukocytes:
1) trophic
2) protective
3) respiratory
4) transport
5) reflex
To count red blood cells in Goryaev’s counting chamber, blood is diluted:
1) 0.1% HCl solution
2) distilled water
3) 0.9% sodium chloride solution
4) 5% acetic acid solution + methylene blue
5) 40% glucose solution
318. The cessation of urine formation is called….
The center of hunger is in...
Adaptation of digestion to a certain nature of food is called...
321. The bactericidal effect of saliva is provided by….
322. Salivary enzymes mainly act on...
323. Constancy of body temperature is called...
324. An increase in body temperature above 37 0 C is called....
325. A decrease in the sensitivity of receptors to a stimulus is called...
326. At the tip of the tongue there are taste buds that are mainly sensitive to
327. Closing your eyes when there is a flash of light is…. Reflex
328. The ability to quickly and firmly develop conditioned reflexes is observed in...
329. Establish the correct sequence of phases of the chewing cycle
1) approximate chewing
2) swallowing
3) eating
4) true chewing movements
5) resting phase
330. Indicate the correct sequence when inhaling
1)excitation of motor neurons of the respiratory muscles
2) stimulation of the bulbar part of the respiratory center
3) contraction of the intercostal muscles and diaphragm
4) increase in chest volume
5) air entry into the lungs
6) stretching of the lungs and decrease in alveolar pressure
Digestive juice produced by the glands of the gastric mucosa; is a colorless transparent liquid with a sour taste. The cells of the stomach glands are divided into main, parietal and accessory; each group of cells produces certain components of the juice. The main cells produce enzymes, with the help of which food substances are broken down: pepsin, which breaks down proteins; lipase, which breaks down fat, etc. Parietal cells produce hydrochloric acid, which creates an acidic environment in the stomach cavity. Concentration of hydrochloric acid in liquids. person is 0.4-0.5%. She owns a special and extremely important role in digestion: it softens certain substances of the food bolus, activates digestive enzymes, kills microorganisms, enhances the production of enzymes by the pancreas, and promotes the formation of digestive hormones. The content of hydrochloric acid in the liquid. is defined by the concept of “acidity”. Acidity is not always the same; it depends on the rate of juice secretion and on the neutralizing effect of gastric mucus, which has an alkaline reaction, and also changes with diseases of the digestive system. Accessory cells secrete mucus, which gives gastric juice viscosity; mucus neutralizes hydrochloric acid, reducing the acidity of the stomach, protects the mucous membrane from irritation and takes part in the digestion of nutrients that enter the stomach. In addition to enzymes, mucus and hydrochloric acid, Zh. contains a number of organic and inorganic substances, as well as a special substance - the so-called. Castle factor, which ensures the absorption of vitamin Bi 2 in the small intestine. This vitamin is necessary for the normal maturation of red blood cells in the bone marrow.
The digestive power of gastric juice secreted at different periods of secretion, as well as various departments stomach, not the same.
Research by I.P. Pavlov has established that secretion is not continuous: in normal conditions, outside of digestion G. s. It is not released into the stomach cavity; it is released only in connection with food intake. In this case, juice can be released not only when food enters the mouth or stomach, but already at the sight, smell, and even when talking about food. Unpleasant smell or the type of food can reduce or completely stop the secretion of fluid.
For diseases of the stomach, intestines, liver, gall bladder, blood, etc., the amount of liquid. and its composition may change. Research J. s. is an important diagnostic method and is carried out with the help gastric tubes, which are injected into the stomach on an empty stomach or after special irritants of the gastric glands - the so-called. trial breakfasts. The stomach contents are removed through a tube and then analyzed. Probes with a sensor that responds to acidity, temperature and pressure in the stomach are also used.
Quantity and quality of housing. may change under the influence of nervous shocks and experiences. Therefore, in order to correctly judge existing changes, it is sometimes necessary repeated tests J. s.
J. s. used as a medicine for stomach diseases accompanied by insufficient secretion of juice or reduced content there is salt in it. For this purpose, natural and artificial iron are prescribed. Take it only as prescribed by a doctor. See also Digestive system.
