Патологическая физиология теоретический курс = Pathological physiology theoretical course. Учебное пособие

mesentery, blood flow in the vessels slows, put in place of the fusion of two small veins into one small crystal of table salt and observe the process of formation of a white clot. Then using a microscope with a dissecting needle to break the wall of one of the small arteries and trace the process of bleeding and the formation of a red blood clot in the lumen of the damaged vessel.

4.In the immobilized frog, open the chest cavity, expose the heart and cover it with a thin layer of cotton wool soaked with physiological solution. Fix the frog on the board with the back up and prepare for the microscopy the vessels of the tongue according to the procedure described above. The drug should be placed under a microscope with a lowmagnificationand determine the initial state of blood circulation in the language of the frog. Gently lifting the animal behind the hindlimbs, inject into the cavity of the ventricle of the heart 0.2-0.3 ml of slightly warmed vaseline oil or fat emulsion pre-colored by Sudan. Continue to monitor the blood flow in the vessels of the tongue and the movement in their lumen of fat particles.

5.Determine the initial physiological state of the rabbit, rat or dog, then intravenously inject 3-5 ml (dog – 30-50 ml) of air and follow the responses of the animal.

Control questions

1.The concept of microcirculation. Its disturbances in disorders of peripheral circulation.

2.The main forms of local manifestations of circulatory dis-

orders.

3.Arterial and venous hyperemia, causes and mechanisms of occurrence.

4.Ischemia, the causes and mechanisms of its origin and development. External signs of local anemia.

5.Thrombosis. Causes and conditions of blood clot formation. Process of thrombogenesis.

6.Embolism, its features. Types of embolism.

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7. Consequences of hyperemia, ischemia, thrombosis and embolism for the body: disorders of a local and general nature and their mechanisms.

T o p i c 1 0

HEMORRHAGE, ITS CAUSES AND CLASSIFICATION.

MECHANISMS OF COMPENSATION

WITH BLOOD LOSS

Purpose of the lesson. Experimentally study the causes and main signs of various types of bleeding. To clarify the role of the compensatory mechanisms of the organism in acute blood loss.

Tasks.

1.Determine the nature of effusions and the color of the blood, the type of bleeding in the animal (under anesthesia) with damage to various blood vessels.

2.Find out what functional changes from the cardiovascular and respiratory systems are accompanied by a rapid loss to animals of 30-35% of the blood. Determine the time of development of compensatory changes in the body and explain the ways and mechanisms of compensation for blood loss.

3.In the experiment on a frog under a microscope to study changes in blood circulation in the vessels of the tongue, which occur with significant blood loss and subsequent transfusion of the blood substitute.

Research Methodology

1. Fixate an animal (dog, rabbit or rat) on an operating table under the usual anesthesia. Cut the hair on a small area of the skin in the hiparea. Observing the rules of aseptic and antiseptic, using a scalpel, cut the skin, subcutaneous tissue, muscles step-by-step. When bleeding occurs, carefully examine the damaged vessels, determine the character of effusion (speed, uniformity) and the

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color of the blood. Pay attention to the fact that the flow of blood from the cut vessel ceases after pressing the central or peripheral end. For these indicators, establish the type of bleeding. Then, using a tampon, a hemostatic tweezers or a tourniquet to quickly stop bleeding, if necessary, to bandage the damaged vessels, treat and sew the wound.

2. It is more convenient to carry out the experiment on a dog, a rabbit, in which without complex equipment it is possible to determine accurately the frequency and strength of the heart contractions, the frequency and volume of breathing, the blood pressure. The accuracy and reliability of the results obtained is enhanced by the use of methods for graphical recording of these indicators. To do this, it is necessary to assemble and prepare for the work the corresponding setup (see: Petrov I.R., Koropov V.M. Practical manual on pathological physiology (Moscow: Kolos, 1964, pp. 24-51).

Fixate on the operating table under the usual anesthesia animal. Dissect carotid artery and jugular vein in the neck. On the peripheral end of the prepared artery, apply a ligature, the central clamped with the Dieffenbach terminal. Between the ligature and the clamp in the wall of the artery to make a small scissors with a special thin vascular hook, insert the glass end cannula into the central end of the artery and strengthen it with a thread. The cannula must be pre-filled with a solution to prevent blood clotting (heparin, 5% sodium citrate solution), and by a rubber tube is included in a single system with a mercury manometer, scribe and kymograph tape.

Record on the kymograph the initial values of blood pressure, ventricular amplitude, pulse and respiration rate. In the jugular vein, insert a cannula with a tap. Without stopping recording, you can release blood from the vein through the canula (up to 30-35% of the total, calculated by weight and fatof the animal). Continue to monitor changes in blood pressure, frequency and amplitude of heartbeats and respiratory movements. Determine the time of onset and the degree of compensatory

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changes on the part of the circulation and respiration. When analyzing the kymogram, the studied indicators are translated into digital data.

3. Stretch the tongue of the immobilized frog above the rectangular window of the cork plate (see topic 9, task 16) and place it under a microscope. After observing normal blood circulation in the animal's tongue, perform bloodletting from the femoral artery. For this, dissect and cut it in the middle part of the lateral side of the thigh. Continuing to observe the vessels of the tongue and the intensity of blood flow in them, determine the nature of compensatory-adaptive reactions of the cardiovascular system with large blood loss. Then stop the bleeding, insert into the dorsal lymphatic sac or abdominal vein 2-3 ml of physiological solution (0.65% sodium chloride). To trace the restoration of the initial level of hemodynamics in the tongue.

Control questions

1.Bleeding, its causes and classification.

2.The main signs of external (arterial, venous, capillary) and internal bleeding.

3.Consequences of bleeding.

4.Compensatory-adaptive reactions of the organism to acute and chronic hemorrhage.

T o p i c 1 1

INFLAMMATION. LOCAL AND GENERAL DAMAGES IN THE ORGANISM DURING INFLAMMATORY PROCESSES. DISORDERS

OF CIRCULATION IN INFLAMMATION AREA

Purpose of the lesson. Make sure that inflammation in damaged tissues and in the animal's body produces a complex of physiological and pathological reactions, to clarify their causes

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and mechanism of development, to become familiar with the most specific local and general manifestations.

Tasks.

1.To find out how the animal and its tissues react to the action of damaging agents (for example, turpentine when administered under the skin); what is the essence of the pathological process developing at the site of the injury, what are its clinical signs, whether other organs and systems of the body are involved in this process (whether the state of the nervous system, thermoregulation, circulation, respiration, blood, digestion, etc. is changing).

2.To determine the mechanism and sequence of vascular reactions and circulatory disorders in general, the development of phenomena of exudation and emigration of leukocytes, diapedesis of erythrocytes during inflammation in the mesentery of the intestine in the frog.

Research Methodology

1. The etiology, pathogenesis and symptoms of inflammation can be studied both in the experiment and on clinical samples in diseased animals obtained in working conditions. For experimental reproduction of acute purulent inflammation (aseptic abscess), three dogs or rabbit are required. The experiment will be more indicative when it is staged on animals of white fur.

One of the animals for three days, and the other the day before the classes are introduced 2-3 ml of sterile 50% emulsion of turpentine in vegetable oil under the skin in the chest area. At the site of the proposed injection, pre-cut the hair in a 5-8 cm diameter area (the third animal will serve as a control).

During classes animal should be clinically examined, paying special attention to the condition (color, volume, density and elasticity, pain sensitivity, local temperature) of the skin and tissues in the area of the injection. Compare the data of experimental and control animals.

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To assess the general condition of animals, the manifestation of behavioral reactions, appetite, to measure rectal temperature, pulse and respiration rate, to determine the rate of erythrocyte sedimentation, the relative number of leukocytes in the blood, and the leukogram (the methods of determination are mastered by students when studying the course of normal physiology).

When analyzing the results of studies and comparing the data obtained, an opinion should be drawn on the nature and extent of local and general disorders in the body during inflammation, their interrelationships, the causes and mechanism of development, and the clinical and diagnostic significance.

2. Circulatory disorders in the area of inflammation are studied in I. Conheim's experiment on a frog. For this purpose it is more convenient to use males whose mesentery of the intestine is more freely located.

In the dorsal lymphatic bag of the frog enter (depending on the weight of the animal) 1.5-2.0 ml of a 10% solution is truncated (the state of anesthesia comes in 10-15 minutes). The frog should be placed on the wooden board with its back up so that the right side in its middle third abuts against the round hole. By scissors layer by layer cut the skin, muscles and peritoneum on the right side of the abdomen in the middle and back of its third. From the opened abdominal cavity carefully, without injuring the organs, remove the loop of the small intestine, the mesentery and spread it over the side opening on the plate. The loop of the intestine is placed around the hole in the form of a horseshoe. Mesentery is strengthened by pins (to put in a free, not mesenteric, edge of the intestinal wall, and then in a plate, closer to the opening). When using frog-females in the experiment, the more superficially and slightly pigmented bulky oviducts and caviar are removed or (to prevent bleeding) placed on the back of the animal.

If the mesentery is straightened, but not stretched excessively and if it lies above the plate opening horizontally, and at the root of the mesentery there is no hemorrhage from an inadvertent sipping of the loop of the intestine, then the preparation is

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correctly prepared. Extraction of the intestine from the cavity of the peritoneum and fixation of it on the plate is accompanied by mechanical trauma, drying, chemical and bacterial action on the peritoneum, which causes the development of an acute inflammatory reaction. Therefore, by the time of full readiness of the preparation for study, an inflammatory reaction of the vessels is already developing.

The preparation of mesentery should be considered under a small increase in the microscope. For studying, choose small arteries, arterioles, capillaries and venules (they are larger at the intestinal wall and less at the root of the mesentery). The vessels in the field of view of the microscope should not be pigmented and thick-walled, the central (axial) layer of blood flow in which elements move, and the peripheral (plasma) layer, free of blood cells, should clearly differ. Particular attention should be focused on changes in lumen and rectilinear vessels, the number and width of capillaries, changes in blood flow velocity and width of the plasma space in arterial and venous vessels.

Note the time of occurrence in the plasmatic space of leukocytes in the form of silver balls moving along the wall (redistribution of shaped elements in the blood stream) and the beginning of the marginal standing of leukocytes. Under a large increase in the microscope, trace the process of emigration of leukocytes. To determine from which vessels (arterial, venous, capillary) the leukocytes emigrate, how they change their shape, to note the presence of diapedesis of erythrocytes and its origin. Draw and briefly record the various phases of the vascular reaction in the protocol of the experiment. Conduct an analysis of the observed phenomena.

Control questions

1.Definition of the term "inflammation".

2.Inflammatory reaction as one of the forms of protection of the body when exposed to a pathogenic stimulus.

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3.Etiology and pathogenesis of inflammation.

4.The main signs of inflammation.

5.Disturbance of blood circulation and phase of development of the vascular reaction in inflammation, causes and mechanisms of microcirculatory disorders in the focus of inflammation.

6.Exudation and emigration of leukocytes, causes and mechanisms of their development.

7.Inflammation as a reaction of the whole organism. Interrelation of local and general disorders in the body with inflammation.

T o p i c 1 2

CHANGES OF METABOLISM IN TISSUES

WITH INFLAMMATION. EXUDATION.

COMPOSITION AND PROPERTIES

OF THE PURULOUS EXPADE

Purpose of the lesson. To study the physico-chemical shifts in tissues during inflammation, the morphological composition and biochemical properties of purulent and other types of exudate.

Tasks.

1.To study under a microscope and to draw a morphological picture of a purulent exudate.

2.Determine the pH and osmotic pressure of the purulent exudate.

3.Determine the proteolytic and amylolytic activity of purulent exudate.

4.To study the properties of various types of inflammatory exudates obtained from sick animals.

Research Methodology

Pus and other types of inflammatory exudates for laboratory testing can be obtained experimentally, causing various kinds of

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acute exudative inflammation in animals, as well as from sick animals in outpatient and clinical conditions.

1.To study the morphological composition of pus, prepare a smear from a drop of exudate, dry, fix and color according to Romanovsky-Giemsa (the technique is described in detail in topic 6).

Under a microscope with an immersion objective study the morphological picture of purulent exudate. Investigating the drug at various sites, detect and draw purulent bodies at different stages of decay (deceased leukocytes in the main neutrophilic series), dead and broken cells of damaged tissue, bacteria, erythrocytes, fibrin strands, and newly formed cells of local tissue. In the protoplasm of individual leukocytes (purulent bodies), detect microorganisms that have undergone phagocytosis.

2.To determine the value of the active reaction (pH) of pus, the strip of the universal indicator should be lowered into the studied exudate. By comparing the resulting paper color with the indicator scale, set the pH value (the normal pH of the tissue fluid is 7.2-7.4).

If there is an automatic pH meter equipped with a needle electrode in the laboratory, it is possible to measure the pH of the exudate and tissues in the animal directly in the center of inflammation, in the center and periphery, and also in healthy areas. The magnitude of the osmotic pressure of the exudate can be measured in a cryoscope using a Beckmann thermometer (see: Guide to practical classes in pathological physiology, edited by S.M. Pavlenko, Moscow: Meditsina, 1974, 58-59). With the help of a cryoscope, the freezing temperature of pus is determined, and then the blood serum with an accuracy of 0.1° C. Usually, the freezing point (A) of purulent exudate (from -0.8 to -1.5° C) is much lower than the freezing point of blood serum (-

0.54to -0.56° C). Knowing that the osmotic pressure in the solution of the molar concentration (1 g /mol per liter of water) is

22.4atm, and the freezing point of such a solution is below the freezing point of pure water by 1.85° C, it is easy to determine

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the osmotic pressure of pus and serum in the atmosphere. If, for example, for pus A = -0.83° C, then the osmotic pressure of pus is 22.4x0.83/1.85=9.99 atm.

3. The presence of various hydrolytic enzymes in the exudate and their activity can be established using simple qualitative and quantitative methods.

To determine the proteolytic ability of purulent exudate, freshly prepared blood serum should be poured into a Petri dish and allowed to curtail, apply a few drops of pus to the surface of the serum and (for control) one drop of saline. Then, the Petri dish is closed and placed in a thermostat at a temperature of 4550° C. A day later, under the drops, the result of the action of en- zymes-proteolysis (when the cup is tilted) is observed. Instead of blood serum, a 10% gelatin solution can be used. In this case, the samples can be kept at room temperature.

If it is necessary to more fully study the inflammatory process and determine the degree of its expression and the stage of the flow, the enzymes of the exudate can be titrated. Proteolytic pus enzymes are titrated to establish the least amount of pus sufficient to break down a certain amount of protein. To this end, different amounts of pus are mixed with an equal amount of protein solution. The decomposition of protein under the influence of proteolytic enzymes pus is judged by the results of adding to the solution of acetic or sulphosalicylic acid. The uncleaved protein coagulates in an acidic medium and gives a turbidity. With complete cleavage of the protein from the addition of the acid to the test liquid, it does not grow turbid.

When analyzing the exudate for the content of amylolytic enzymes, 0.25-1.0% starch solution is used as the object of digestion. The degree of its cleavage is assessed by the iodine reaction, since iodine with starch gives a violet color. As the substrate is cleaved, the intensity of the staining changes from violet (iodine to starch), violet-red (amylodextrin), red-violet, red (erythrodextrin) to colorless (achrodextrin).

To quantify the amylolytic activity of pus in 8 numbered tubes, pour 1 ml of 0.25% starch solution (0.25 g of soluble

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