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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 thoracic vertebrae. The right adrenal gland lies slightly below the left. The back surface of the right adrenal gland is adjacent to the lumbar part of the diaphragm, the front surface is in contact with the visceral surface of the liver and duodenum, and the lower concave with the upper end of the right kidney. The left adrenal anterior surface adjoins the tail of the pancreas, the cardiac part of the stomach, its posterior surface comes in contact with the diaphragm, and the lower surface - with the upper end of the left kidney.
The surface of the adrenal gland. On the anteromedial surface, a deep groove is visible — the organ's gate, through which the central vein and lymphatic vessels exit. Outside, the adrenal gland is covered with a fibrous capsule, which fuses tightly with the parenchyma and gives numerous connective tissue capsules deep into the gland. Under the fibrous capsule is a cortical substance (cortex), consisting of three zones. Outside, closer to the capsule, there is the glomerular zone, then - the middle, the widest tuft zone, and then the inner mesh area adjacent to the medulla.
In the adrenal cortex, hormones are produced under the general name corticosteroids. They are divided into two main groups: 1) glucocorticoids (corticosterone, cortisol, hydrocortisol, and cortisone), which are formed in the bundle zone; 2) mineralocorticoids (aldosterone) secreted by the glomerular cells of the cortex. In addition, in the adrenal cortex, mainly in the reticular zone, a small amount of male genital substances, similar in structure and function to the hormones androgens, as well as estrogens and progesterone, are secreted.
In the central part of the adrenal gland is located the medulla formed by large cells, which are stained by chromium salts in a yellow-brown color. There are two types of these cells: epinefrocytes - make up the bulk and secrete adrenaline and norepinefrocytes - produce norepinephrine.
Glucocorticoids have a different effect on metabolism.
They stimulate the synthesis of glycogen from glucose and proteins and the deposition of glycogen in the muscles, while raising the level of glucose in the blood; significantly affect cellular and humoral immunity, have a strong anti-inflammatory effect. Especially clearly observed changes in the concentration of glucocorticoids under stress. According to the theory of stress, G. Selye identifies three of his phases: anxiety, resistance, and devastation. Stress-reaction can pass without a trace, if the influence is not very strong; with its repetition, adaptation to this stimulus is possible. If the stress is very intense, then all the glucocorticosteroids in the adrenal cortex may be devastated and destroyed.
Changes in the concentration of glucocorticoids both upward (hyperfunction) and downward (hypofunction) leads to serious disturbances in the body. As a result of increased secretion of cortisol, obesity, enhanced protein breakdown (catabolic effect), water retention, hypertension, etc. are observed. When the adrenal cortex function is insufficient, and the production of corticosteroids is reduced, Addison's disease occurs. It is characterized by bronze coloring of the body, increased fatigue, hypotension, weakness of the heart muscle, etc.
Mineralocorticoids (aldosterone) regulate the exchange of Na + and K4, acting mainly on the kidneys. With an excess of the hormone, the concentration of Na4 'increases and IC decreases in the blood, its osmotic pressure increases, water in the body is retained, and blood pressure rises. Deficit hormone leads to a decrease in the level of Na + in the blood and tissues and to an increase in the level of K ^. The loss of Na + is accompanied by the removal of fluid from the tissues - dehydration.
Adrenaline affects the cardiovascular system: increases blood pressure, heart rate and strength, dilates the vessels of skeletal muscles, smooth muscles of the bronchi. In addition, it increases the content of glucose in the blood, enhances the oxidative processes in the cells. The release of adrenaline in the blood occurs under the action of the sympathetic nervous system.
Norepinephrine helps to maintain the tone of the blood vessels, is involved in the transfer of excitation from sympathetic nerve fibers to the injected organs.
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- 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.
- 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
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 develops.
- 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
- Congenital dysfunction of the adrenal cortex (adrenogenital syndrome)
Congenital dysfunction of the adrenal cortex is a group of diseases with an autosomal recessive mode of inheritance, based on a defect in one of the transport proteins involved in the biosynthesis of cortisol by the adrenal cortex. In the pathogenesis of these conditions, a decrease in cortisol synthesis occurs, which leads to hyperproduction of ACTH, the development of adrenal hyperplasia and accumulation