Animal anatomy, histology, pathological anatomy

PathanatomyThe gastric mucosa is swollen, pinpoint hemorrhages form on its surface, and exudates are visible.
Enteritis is characterized by inflammation of the mucous membrane of the small intestine, a disease that also often occurs as a complication of malnutrition and, of course, infectious diseases.
Pathological anatomy of the intestinal mucosa thickens, exudate appears on their surface, at the base of which nodules form, we see injuries to the mucous membranes.
Colitis is characterized by inflammation of the colon mucosa. 3. Toxic liver dystrophy is usually an acute disease in which the liver is affected by more degenerative changes, in which extensive foci of necrosis occur, which sometimes affect almost the entire liver. includes.
The etiology of dystrophy is varied. Occurs when animals eat low-quality food poisonous weeds, poisoning with chemicals, mineral fertilizers. Sometimes this happens during calving of the melody, in the period after the cows calve. It is also observed in various infectious diseases, in chronic forms of infectious anemia, and in salmonellosis.
The pathogenesis of toxic hepatic dystrophy depends on the characteristics of the causative factors of the disease. The pathological anatomy of toxic liver dystrophy consists of dystrophic changes in the OG 'IR parenchyma.
Liver cirrhosis is a chronic disease, and the main process is the following changes
these are: degeneration of liver cells, regeneration of connective tissue growth, disruption of the structure of the organ, deformation of the liver due to escalation of processes.
The pathogenesis of liver cirrhosis is closely related to its etiology. However, the mechanism of occurrence of cirrhotic changes may be the same for different etiological factors. Dystrophic changes lead to the appearance of small or large foci of necrosis in the liver, creating favorable conditions for the development of regeneration processes, connective tissue growth and deformation processes.
Pathomorphology of the digestive system. Diseases of the stomach. Gastritis - Gastritis. Inflammation of the mucous membrane and other layers of the stomach wall, accompanied by functional and morphological disturbances of its activity. By origin: primary and secondary. According to the course: acute and chronic. According to the nature of inflammation: serous, catarrhal, fibrinous (croupous and diphtheritic), hemorrhagic, purulent. By distribution: focal and diffuse. The disease is widespread in all animal species, and especially among young animals. Disorders of secretory function are manifested by an increase or decrease in the amount of digestive juices in the stomach and an increase or decrease in acidity. Taking this circumstance into account, in disorders of the function in question, four forms of disorders are distinguished. 1.Hyperacid. It is usually expressed by an increase in the amount of gastric contents and its acidity, an increase in both cases by 2-3 times. 2. Hypoacid. This form of secretion is characterized by a normal or reduced amount of gastric contents and a decrease in the values ​​of total acidity and free hydrochloric acid. 3. Anacidic. With this form, the amount of gastric contents, an indicator of total acidity, decreases, and free hydrochloric acid is usually not detected. 4. Normacidal. It is characterized by a normal amount of stomach contents and close to normal levels of total acidity and free hydrochloric acid. Pathological changes. Serous gastritis is characterized by swelling and hyperemia of the mucous membrane, sometimes with hemorrhages, mainly in the fundus of the stomach. Macroscopically and histologically, this is the initial stage of other forms of inflammation. In piglets, gastritis may be accompanied by uneven spotty hyperemia. Hemorrhagic inflammation in them is more often recorded in a diffuse form, covering large areas of the mucous membrane and even the entire bottom of the stomach with a clear staining of it in a dark brown color with hydrochloric acid hematin. Before weaning, piglets have undigested casein in the stomach cavity. In older age, with acute inflammation, the contents of the stomach are liquefied, there is a lot of mucus in the form of strands, thick films and compacted clots. Histologically, mucous degeneration, infiltration of the mucous and submucosal layers with serous exudate, vascular hyperemia, and sometimes necrosis and desquamation of the glandular epithelium are noted in the epithelial layer. With chronic gastritis, the contents of the stomach contain a lot of thick, viscous, cloudy mucus, which in significant quantities is located on the surface of the mucous membrane in the form of difficult-to-wash off deposits. In the mucosa, hypertrophic processes predominate, and in some areas atrophic processes predominate, which gives it a sharply folded appearance. With atrophic chronic inflammation, the mucous membrane is thinned and smoothed. Diagnosis. They analyze the conditions of feeding and keeping animals, conduct bacteriological and virological studies, mycological and toxicological analyzes of feed, and examine feces. At autopsy, the nature of the inflammatory process of the mucous membrane is clarified. If necessary, sick and low-value animals are killed and examined for diagnostic purposes. Peptic ulcer – Morbus ulcus ventriculi Chronic recurrent disease with the formation of peptic ulcers in the stomach, representing acute or chronic destruction of the mucous membrane, which is one of the local manifestations of various diseases. The disease is polyetiological. Caused by both exogenous and endogenous factors. Perforation of the stomach wall is accompanied by diffuse peritonitis with signs of acute septicemia and intoxication. In this case, the punctate of the abdominal cavity contains gastric contents. In pigs, perforation syndrome is characterized by loss of appetite, disappearance of intestinal motility, cessation of vomiting, saccadic (intermittent) breathing, proteinuria, and other symptoms of acute septic peritonitis. A small perforated hole may well be closed through the adhesive process by the omentum, intestinal loops, or spleen. In this case, the symptoms of perforation and peritonitis gradually disappear. In cattle, defects are localized in the fundic and pyloric zones of the abomasum. In adult and fattening pigs - mainly in the esophagus, in piglets - in the fundic zones of the stomach. In pigs, keratinization (hyperkeratosis) first occurs in the glandular area of ​​the mucous membrane of the esophagus. Erosion is usually multiple; young animals may have large areas with areas of inflammation of varying severity. Ulcers range in size from a few millimeters to 10 cm or more. They are covered with a scab; in gilts and adult animals, a ridge forms around the perimeter of the defect. Chronic ulcers heal through scarring. Bleeding deep erosions and ulcers are colored brown with hydrochloric acid hematin. After their healing, pigmentation remains. With complications of the disease, blood is found in the stomach, and with intense flow, blood clots are found. In case of perforation, signs of limited or diffuse peritonitis are noted. Histologically, the mucous membrane reveals the phenomena of dystrophy, necrosis, rejection of cells of the integumentary epithelium and glands, hyperemia of capillaries and small veins to stasis and the development of serous edema. When making a diagnosis, the technological situation, disease status, and autopsy results are taken into account. Gastroenteritis - Gastroenteritis Characterized by inflammation of the stomach and small intestine, accompanied by functional disorders, as well as structural (morphological) disorders. Cathars are predominantly registered. 26 Pathomorphological changes are clearly expressed. The mucous membrane is swollen, reddened in places, with the presence of hemorrhages and erosions, covered with glassy or mucopurulent viscous exudate, often containing epithelial cells and blood cells. Microscopy of the mucosa indicates degeneration of the integumentary epithelium (enterocytes) and the epithelium of the gland ducts, and infiltration of connective tissue. Electron microscopy reveals disturbances in the structure of cell membranes. The stool is thin or liquid, usually with a foul odor. Diagnosis and differential diagnosis are made based on history, clinical symptoms and special research methods. Enterocolitis – Enterocolitis The disease is characterized by inflammation of the small and large intestines, with disruption of their functioning. Animals of all species and all age groups are affected, but especially young cattle and fattening pigs, as well as carnivores. The mucous membrane is predominantly affected. When the stomach (abomasum) is involved in the process, the disease is called gastroenterocolitis. Pathomorphological changes. With catarrhal inflammation, hyperemia, hemorrhages, and catarrhal exudate are noted. In other forms of enterocolitis, other layers of the intestinal wall are also affected - submucosal, muscular, sometimes serous with the presence of one or another exudate - fibrinous, purulent, hemorrhagic. In such cases, the intestinal wall is significantly thickened, and hemorrhages, ulcers and necrosis are observed on its surface. The mesenteric vessels are congested with blood, and the lymph nodes are infiltrated. Hemorrhages are often found on the serous covers, under the epicardium and in the mucous membrane of the bladder. In the differential diagnostic relation, according to the relevant signs and research methods, infectious and invasive diseases accompanied by enterocolitis are excluded. Tympanic rumen. The disease is characterized by an increase in the volume of the scar as a result of intense gas formation, as well as the cessation of gases leaving it. It is divided into gas (simple) and foam (mixed), as well as primary and secondary, acute and chronic. Mostly cattle, sheep and goats are affected, and less often camels. It often takes on a massive scale. Pathomorphological changes. When autopsying corpses, it is discovered that the scar is greatly stretched, its walls are tense. It contains mushy feed mass and a large amount of gases. The abdominal organs are compressed and anemic. There is a rush of blood to the intestines and lungs. The right half of the heart and saphenous veins are filled with blood. Displacement of the abomasum. The disease is rare. It may be accompanied by displacement of the abomasum, usually to the left half of the abdominal cavity under the scar and inversion (twisting). It is registered mainly in cows. Pregnancy and the birth process are considered to be the triggering factors for the disease. Pathomorphological changes When opening a fallen or forcibly killed animal, a change in the location of the abomasum (usually on the left under the scar) and changes on it are detected. At the 27th displacement of the organ, areas of obstruction are visible (this is usually the pyloric region and the initial part of the small intestine). The abomasum is usually filled with feed mass and gases and is increased in volume. The mucous membrane is swollen and hyperemic, the wall is edematous, the folds are prominently enlarged. Liver cirrhosis (Cirrhosis hepatis). Chronic progressive disease, characterized by dystrophy and necrosis of the liver parenchyma, accompanied by diffuse proliferation of connective tissue. It is found in animals of all species, more often in dogs, horses - serum producers, and zoo animals. Etiology. Cirrhosis is the final stage of chronic liver diseases, primarily hepatitis and hepatosis. Therefore, all the causes that cause hepatitis and hepatosis can serve as the etiology of liver cirrhosis. They are, in particular, long-term exposure to the liver of rotting feed products, toxins of plant origin (lupine alkaloids, mustard oils of rapeseed, mustard, etc.), pesticides, nitrates and nitrites. Liver cirrhosis occurs when livestock is constantly fed with sour grain stillage, brewer's grains, or chronic underfeeding of animals. The disease often develops against the background of helminthic liver lesions. In pigs, cirrhosis is often caused by feeding rancid fats and spoiled kitchen waste. Pathogenesis. Connective tissue grows due to initial dystrophic and necrotic damage to the parenchyma. The progression of liver cirrhosis is a characteristic feature of its pathogenesis. The mechanism of this process is associated with hepatocyte necrosis, regeneration, inflammatory response and fibrosis. Necrosis of hepatocytes is the initial driving point of the pathological process in cirrhosis. Following the death of hepatocytes, their regeneration begins, which occurs in the form of a concentric increase in the remaining areas of parenchyma, which leads to the formation of pseudolobules. Necrosis of hepatocytes is one of the main causes of the inflammatory response. The end result of the cirrhosis process is the growth of fibrous tissue with all functional disorders. With liver cirrhosis, portal hypertension develops. It is associated with blockage of blood flow due to compression of the branches of the portal vein by nodes of regenerating hepatocytes or overgrown fibrous tissue. Portal hypertension, in turn, is accompanied by splenomegaly and ascites. Due to compression of the bile ducts, stagnation of bile is noted, leading to jaundice. The secretion of bile is sharply reduced, the neutralizing function of the liver decreases, a violation of all types of metabolism occurs, and self-poisoning of the body occurs. 5.2. Pathomorphology of the organs of the respiratory system Rhinitis is inflammation of the mucous membranes of the nose, can be primary and secondary, acute and chronic, catarrhal, lobar and follicular. Laryngitis is inflammation of the mucous membrane of the larynx. There are primary and secondary, acute and chronic, catarrhal and croupous. Tracheitis is inflammation of the mucous membrane of the trachea. There are primary and secondary, acute and chronic, catarrhal and croupous. 28 Bronchitis - inflammation of the mucous membranes and submucosal layer of the bronchi. According to the course, bronchitis is classified into acute and chronic, by origin - primary and secondary, by the nature of inflammation - catarrhal, purulent, hemorrhagic and fibrinous. From lesions of the bronchi category in the bronchial tree, macrobronchitis (predominantly large bronchi are affected), microbronchitis (small bronchi are affected) and bronchiolitis (bronchioles are affected). Pathoanatomical changes: In acute catarrhal bronchitis, the mucous membrane is hyperemic, swollen, and there is catarrhal exudate in the bronchial lumen. Histological examination reveals desquamation and death of the bronchial epithelium, loss of villi by cells, and a large number of dead cells, leukocytes, erythrocytes, and microbes in the exudate. In chronic bronchitis, atrophy of the mucous membranes, loss of elasticity of the bronchi are noted; in some of them, areas of narrowing (bronchostenosis) or expansion (bronchiectasis), and peribronchitis can be found. There is a small amount of viscous mucous exudate in the lumen of the bronchi, and emphysema in the marginal areas of the lungs. With purulent and fibrinous bronchitis, the mediastinal lymph nodes are enlarged and swollen. Lung diseases. Hyperemia and pulmonary edema (Hyperaemia et oedema pulmonum) A disease characterized by blood overflow of the pulmonary capillaries and veins with subsequent effusion of blood plasma into the lumen of the bronchi, bronchioles and alveolar cavities and infiltration of the effusion of interlobular connective tissue. There are active and passive hyperemia, active and hypostatic pulmonary edema. Passive hyperemia and hypostatic pulmonary edema are recorded in cases of decompensated heart defects, traumatic pericarditis, myocarditis, intoxication, kidney disease, heat and sunstroke, and prolonged forced lying of animals. Pleuritis - inflammation of the pleura. Pleurisy is classified according to its course - acute and chronic; by origin – primary and secondary; by localization – limited and diffuse; according to the nature of the inflammatory process - dry and exudate (wet). Exudative pleurisy can be serous, serous-fibrinous, purulent and putrefactive. With purulent-putrefactive pleurisy, due to the decomposition of exudate, liquid and gases can accumulate in the pleural cavity (hydropneumothorax). In most cases, pleurisy develops as a secondary disease with complications of pneumonia, pneumothorax, traumatic reticulopericarditis, peritonitis, rib caries, septicemia and other diseases. As an independent disease, it occurs relatively rarely, mainly in horses, as a result of a cold or infection due to penetrating wounds of the chest wall. With dry pleurisy, areas of fibrinous inflammation form on the pleura. Exudative pleurisy is characterized by sweating into the pleural cavity and the accumulation in it of first serous or serous-catarrhal exudate, which can later turn purulent. In horses and sheep, the disease is often acute, and in cattle and pigs it is chronic. 29 Diagnosis is made based on history and characteristic clinical symptoms. The differential diagnosis excludes: hydrothorax, hemothorax, pericarditis, lobar pneumonia, chronic nephritis. Transudate with hydrothorax, unlike exudate with pleurisy, has a lower density, it contains less protein and there are no blood elements, with the exception of red blood cells (in small quantities). To exclude infectious diseases occurring with symptoms of pleuritis (contagious pleuropneumonia of horses, pleuropneumonia of cattle, hemophilus pleuropneumonia of pigs, etc.), an analysis of the epizootic situation and relevant laboratory diagnostic studies are carried out. Pneumonia, pulmonitis - Inflammation of the lungs. They are distinguished: serous, catarrhal, serous-catarrhal, catarrhal-purulent, purulent, abscessing, purulent-necrotic, fibrinous, indurative, necrotic, etc. Taking into account the anatomical and pathogenetic principle, lobar and lobular are distinguished. Croupous, fibrinous pneumonia (Pneumonia crouposa s. fibrinosa) A febrile disease characterized by fibrinous inflammation of the lungs of the lobar type. Mostly horses are affected. There are four stages. The stage of inflammatory hyperemia, or tide - there is a pronounced overflow of capillaries with blood, diapedesis of red blood cells in the alveoli and bronchi, serous-hemorrhagic exudate, swelling of the epithelium. The stage of red hepatization is characterized by filling the lumen of the alveoli and bronchi with coagulated substances from erythrocytes and plasma proteins, mainly fibrinogen. Stage of gray hepatization - fatty degeneration of fibrinous exudate occurs with an increase in leukocytes in it. In the resolution stage, fibrinous exudate is liquefied under the influence of proteolytic and lipolytic enzymes, erosorbing and coughing occurs. Sequestration or organization is possible. Pathoanatomical changes In the stage of inflammatory hyperemia, the affected areas of the lungs are increased in volume, swollen, red-blue in color, do not sink in water, and when pressed, a foamy reddish liquid is released from the lumen of the bronchi when cut. In the stages of red and gray hepatization, the affected lungs are airless, dense to the touch, resemble liver in consistency (hence the name hepatization), graininess is expressed on the cut, and they sink in water. In the stage of red hepatization, the coagulated fibrous exudate gives the lungs a red color, and in the stage of gray hepatization, the lung has a grayish or yellowish color, due to fatty degeneration and emigration of leukocytes. In the resolution stage, the lung resembles the spleen in consistency and color, the granularity is less pronounced. Bronchopneumonia (catarrhal pneumonia) - Bronchopneumonia Inflammation of the bronchi and lungs, accompanied by the formation of catarrhal exudate and filling the lumen of the bronchi and alveolar cavities with it. Pathoanatomical changes: In the initial stages and in the acute course, multiple lobular lesions are found in the apical and cardiac lobes in the form of pneumonic foci located superficially or in the thickness of the lung, ranging in size from one to several centimeters, blue-red or pale red in color. They are dense drown in water; when cut, catarrhal exudate is released. Histologically, in the alveoli and bronchi there is catarrhal exudate from mucus, leukocytes, erythrocytes, bronchial epithelial cells, and microbes. In chronic bronchopneumonia, depending on the duration of the process, the presence of extensive pneumonic foci formed as a result of the fusion of lobular lesions is characteristic; pleurisy and pericarditis are detected. Histologically, in these cases, areas of purulent-necrotic decay of the lungs and bronchi and petrification are found. Mediastinal lymph nodes are often enlarged. Atelectatic pneumonia (Pneumonia atelectatica) Inflammation of the lungs of a lobular nature, resulting from the formation of insufficiently ventilated, collapsed or airless areas in the lungs (hypopneumatosis and atelectasis). Subsequently, catarrhal inflammation and the formation of pneumonic foci develop in them. Hypostatic pneumonia (Pneumonia hypostatica) Inflammation of the bronchi and lungs of a lobular nature, occurring against the background of weakened blood flow in the lungs and edema (state of hypostasis). A characteristic feature is the rapid development of the pathological process in the lungs with intoxication and the development of heart failure. Metastatic pneumonia (Pneumonia metastatica) Inflammation of the lungs and bronchi of the lobular type, resulting from the introduction of bacterial flora into the lungs from other organs and tissues of the body, as a complication of infectious, gynecological and surgical diseases. Aspiration pneumonia (Pneumonia aspirationis) Inflammation of the lungs and bronchi of a lobular nature, which occurs when foreign bodies enter the respiratory tract during pharyngitis, intoxication, vomiting, and tympani of the forestomach. In newborn animals, aspiration pneumonia can occur when amniotic fluid enters the trachea, which often happens during prolonged labor. Purulent-necrotic pneumonia, gangrene of the lungs (Gangraepa pulmonum) Lobular inflammation of the lungs, characterized by the accumulation of purulent exudate in the bronchi and lungs, necrosis and melting of necrotic areas under the influence of putrefactive microflora. Emphysema (Emphysema pulmonum) Pathological expansion of the lungs with an increase in their volume and an increased content of air in them. Emphysema is classified into alveolar, when the lungs expand due to alveolar tissue, and interstitial, in which air penetrates into the interlobular connective tissue. Pathological changes. The lungs are enlarged, soft in consistency, their edges are rounded, traces of rib indentations are visible on the surface of the lungs, the color is pale, and they do not collapse when cut. The right ventricle of the heart is usually hypertrophied. Histologically, cavities are detected due to rupture of the alveolar septa, atrophy and thinning of the septa, neglect and atrophy of the pulmonary capillaries. Questions for self-control 1. Macro picture of tympany. 2. Macropicture of gastritis and enteritis. 3. Macro- and micropicture of acute dilatation of the stomach. 4. Macro picture of gastric rupture. 5. Pleurisy. 6. Pneumonia. 31 7. Emphysema. 8. Atelectasis. 9. Pulmonary edema