Licensed books on medicine
<< Ahead || Next >> |
The adrenal glands are located in the form of oval or bean-shaped cells medially and somewhat cranial to the kidneys. They develop from two primordia. The adrenal cortex arises from the epithelium of the splanchnomotomes of the mesoderm near the mesentery root, that is, from the same material as the sex glands and kidneys. The brain substance is formed from the material from which the sympathetic part of the nervous system develops.
The function of the two parts of the adrenal gland is largely determined by their origin. The hormones of the cortical substance in their activities are associated with the work of the kidneys and sex glands, whereas the hormones of the medulla act similarly to the sympathetic nervous system. The hormones of the cortical substance are very numerous, but their composition and action can be combined into three groups.
Some (mineralocorticoids) act on the water-salt metabolism, disrupting, in the case of enhanced function, ionic equilibrium and, as a consequence, the osmotic properties of tissues; increase inflammation and collagen formation. The second group of hormones (glycocorticoids) regulates carbohydrate metabolism. In case of excess, they lead to disintegration of the lymphoid tissue, depletion of blood by lymphocytes and eosinophils, weaken phagocytosis and collagen formation, that is, weaken the body's inflammatory response, at the same time they increase the body's resistance to adverse environmental factors, reduce capillary permeability. The third group of hormones (steroids) acts similarly to male and female sex hormones.
307. Adrenal cut:
/ - capsule; 1 - cortex; 3 - medulla; 4 - glomerular zone; 5 - beam zone; 6 - mesh area.
The cortical substance consists of cords of epithelial cells, which are closer to the surface of the adrenal gland in a horse, pig, and predator form something like loops, for which this zone is called the glomerular. The cells of the glomerular zone of prismatic shape are relatively poor in lipids. They probably produce mineralocorticoids and are probably cambial for the remaining cells of the cortex. Deeper, the cages of cells are located in parallel radial rows — the beam zone. The epithelial cells of the beam zone are characterized by the presence of lipids, the main one is • Cholesterol, which is used in the process of synthesis of adrenal hormones. With increased activity of the gland, the number of granules of lipids, as well as ascorbic acid decreases. The cells of the beam zone are particularly rich in lipids and neutral fats. Therefore, on fixed preparations they have the appearance of a sponge with numerous pores, for which they are called spongocytes. It is believed that glycocorticoids are produced in the beam zone. Finally, the deepest layer consists of strands of cells located randomly, the mesh zone (Fig. 307). The cells of the reticular zone are smaller, often containing pigment inclusions. They are credited with the function of the formation of steroid hormones (andro-gene, estrogen).
The brain substance consists of polygonal cells, in the cytoplasm of which there are pigment grains and grains that are easily stained with ferric chloride and chromium salts, for which these cells are called chromophilic. Due to the strong development of the wide venous sinuses, the cells are in close contact with the bloodstream. The hormone of this tissue is adrenaline and noradrenaline, their action is similar to the action of the sympathetic nervous system.
| << Ahead || Next >> |
| = Go to tutorial content = |
- Adrenal glands
The adrenal glands are a paired organ and are located extraperitoneally at the upper poles of the kidney. Their weight is 4 g regardless of gender and body weight. The uniqueness of the blood supply to the adrenal glands is that each gland is supplied with the blood of three arteries - branches of the diaphragmatic artery with isolated veins one on each side (the right flows into the inferior hollow, the left into the renal). Cortical
- Adrenal glands
As already mentioned, the adrenal glands in newborns are relatively larger than in adults. The adrenal medulla of the newborn is very poorly developed and is almost indistinguishable in macroscopic examination. The cortex consists of two layers - the inner one, the darker one, and the outer one, the lighter one. The adrenal medulla is formed from the inner layer over time (A. F.
The adrenal gland (glandula suprarenalis) is a paired organ located in the retroperitoneal space directly above the upper end of the corresponding kidney. Its mass is 12–13 g, length 40–60 mm, width 2–8 mm. The adrenal gland has the form of a cone compressed from front to back, in which there are distinguished anterior, posterior and lower (renal) surfaces. Adrenal glands are located at the level of the XI — XII infants
- Adrenal Diseases and Pregnancy
Physiology of the adrenal glands The adrenal glands are paired organs of internal secretion, located above the upper poles of the kidneys at the level of the vertebrae from ThXI to L [. Have the appearance of vertically standing flat plates in the form of a pyramid or triangle. The average mass of both adrenal glands is 10–12 g. The dimensions are on average 4.5 x 2-3 cm, thickness 0.6–1 cm. The left adrenal gland is larger than the right one. Rudiments
- Adrenal pathology
Adrenal pathology is very diverse, but pheochromocytoma and Addison's disease are more common. Pheochromocytoma - a tumor of the medulla, leads to an increase in blood pressure (adrenaline and norepinephrine), patients die from bleeding in the brain. Addison's disease is caused by the hypofunction of the adrenal cortex, more often with its tuberculous lesion, less often with amyloidosis, cancer metastases,
- Adrenal insufficiency
1. Give a definition of adrenal insufficiency. Adrenal cortex insufficiency, or Addison's disease, is characterized by reduced production of glucocorticoids and mineralocorticoids by the adrenal glands. The cause of the disease is a pathological process that directly affects the adrenal glands (primary hypoadrenocorticism) or the formation and secretion
- Adrenal glands
Physiology The adrenal glands secrete the cortex and medulla. The adrenal cortex is the source of three types of hormones: androgens, mineral-corticoids (for example, aldosterone) and glucocorticoids (for example, cortisol). In the medulla of the adrenal glands, catecholamines are produced (adrenaline, norepinephrine, dopamine). Adrenal androgens are not essential for anesthesia and
- Hyperfunction of the cortex of the adrenal glands
Hyperfunction of the adrenal cortex is a disease that occurs rarely in cats. It is caused by increased synthesis of the hormone cortisone, which leads to metabolic disorders and various pathological processes. The cause may be a tumor of the adrenal glands or pituitary gland. Symptoms: hair loss, swelling, possible liver failure. Treatment usually
- Adrenal glands
The adrenal cortex produces more than 60 biologically active substances and tissue hormones of a steroid nature, which, by their effect on metabolic processes, are divided into glucocorticoids (cortisone, cortisol), mineralocorticoids (aldosterone, 11 - deoxycorticosterone), sex hormones - androgens (17-ketosteroids) and testosterone) and trace concentrations of female sex hormones -
- Adrenal glands (problems)
Physical blocking The adrenal glands are the paired endocrine glands, as the name implies, located above the kidneys. They perform several functions: if necessary, they release adrenaline, which activates the brain, accelerates heart rate and mobilizes sugar from the reserve, when the body needs additional energy. They secrete cortisone - a hormone that plays
- Congenital adrenal hypoplasia
Etiology The hereditary form associated with the X chromosome and caused by defects in the NR0B1 gene encoding a DAX1 transcription factor is most common. Pathogenesis DAX1 factor is necessary for laying the adrenal cortex and testicles, is involved in the regulation of the hypothalamogonadotrophic function. Clinical picture With a defect of factor DAX1 in boys, adrenal insufficiency occurs, clinically
- Anesthesia for adrenal surgery
Anesthetic management during interventions on the adrenal glands is classified as rather complicated. This is due not only to the fact that the adrenal glands produce hormones important for the course of many processes (gluco - and mineralocorticoids, catecholamines). Adrenal hormones have a significant impact on the state of the main vital functions and, above all, on the blood circulation, are involved in
- Adrenal tumors.
Adenomas of the adrenal cortex. Classify depending on hormonal activity and cytogenesis (Table 35.3). Aldosteroma. Develops from the glomerular cells, produces minerolocorticoids, is clinically characterized by development. Table 35.3 Clinical and morphological features of adrenal adenoma. Name of adenoma. Source of growth. Clinical characteristics of the Aldosteroma of the glomerular.
- Diseases of the adrenal cortex
Gordon G. Williams, Robert J. Dluhi (Gordon H. Williams, Robert K. Diuhy) Biochemistry and physiology of steroids Nomenclature of steroids. The structural basis of steroids is the cyclopenten-perhydrophenanthrane core, consisting of three 6-carbon hexane rings and one 5-carbon pentane ring (D, in Fig. 325-1). Carbon atoms are numbered in sequence, starting from ring A
- Lipoid hyperplasia of the adrenal glands
Etiology At the heart of most cases of lipoid hyperplasia of the adrenal glands are defects of the STAR gene encoding the StAR protein. More rarely, the disease is caused by defects in the CYP11A1 gene encoding P450scc (steroid 20,22-desmolase). Both proteins are necessary for the implementation of the first stage of the biosynthesis of steroid hormones - the conversion of cholesterol into pregnenolone. When the lipoid hyperplasia of the adrenal glands occurs