Diseases of the adrenal medulla
Endocrinology / / August 12, 2017
adrenal medulla in an adult is about 20% of the weight of the adrenal glands.The medulla is located in the central part of the adrenal gland, is surrounded on all sides by a layer of cortical tissue.It consists of a large, so-called hromaffinovyh cells containing granules stained with chromium salts.Some of these cells produce adrenaline others - noradrenaline.Hromaffinovye cells are located in connective cords glands basis.
clusters hromaffinovyh cells, in addition to the adrenal medulla, found near the sympathetic ganglia - in the field of solar, kidney, adrenal, aortic and epigastric plexus (chromaffin body), in front of the abdominal aorta and above the inferior mesenteric artery at the site of origin of the aorta inferior mesentericartery (Zuckerkandl body).These clusters of tissue hromaffinovoy in early childhood are a major part hromaffinovoy system further regress.They can be a source of education hromaffinovyh tumors.
adrenal medulla hormone produces three united called catecholamines or amin
Way adrenaline biosynthesis are shown in the diagram.
Norepinephrine is produced in addition to the adrenal medulla and in the sympathetic nerve endings, without being there is further converted into adrenaline;noradrenaline is the main mediator of the sympathetic impulses.
ratio of adrenaline and noradrenaline in the adrenal gland of an adult is about 1: 5. In the fetal adrenal detected only norepinephrine.
catecholamine secretion by the adrenal medulla is subject to large fluctuations, depending on a variety of stimuli, ranging from 0.5 to 1.5 g per minute.
circulating catecholamines in blood due to plasma proteins, mainly albumin, proteins and blood cells.Integration of catecholamines protein is important in the stabilization and inactivation of these hormones.
- Physiology of the adrenal cortex
- Syndrome Cushing - Cushing
- diagnosis and course of the syndrome Cushing's
- syndrome Treatment of Cushing's
- Biological effects of catecholamines
- Primary aldosteronism (Conn's syndrome)
- Clinical evaluation of laboratory studies of the functional state of the adrenal cortex
- feminizing tumor of the adrenal cortex
- diagnosis and differential diagnosis of congenital adrenal hyperplasia
- Treatment of chronic adrenal insufficiency
- congenital (inborn) hyperaldosteronism
- congenital virilizing adrenal hyperplasia
- Treatmentcongenital adrenal hyperplasia
- Acute adrenocortical insufficiency
Catecholamines rapidly absorbed by the tissues;binding their tissues affect the sympathetic impulses.Denervated tissue absorbs less catecholamines than normal.
Inactivation of catecholamines is performed by O-methylation, quinoid oxidation, oxidative deamination with monoamine oxidase binding to glucuronic and sulfuric acids.
regulation of secretion of catecholamines is performed sympathetic division of the autonomic nervous system.The regulation involves the central parts of the system - centers located in the area of the bottom of the IV ventricle, hypothalamus, reticular formation, some sections of the cerebral cortex, which receives impulses from peripheral nerve endings.Effector link is a great splanchnic nerves and nerve fibers originating from various sympathetic plexus.