A Simple Guide to the Adrenal Gland and Its Disorders, Diagnosis, Treatment and Related Conditions

This book describes The Adrenal Gland and Its Disorders, Diagnosis and Treatment and Related DiseasesThe adrenal glands are endocrine glands that are located at the top of the kidneys. In humans, the right adrenal gland has a triangular shape while the left adrenal gland has a semi lunar shape. They are mainly accountable for releasing hormones in reaction to stress through the synthesis of corticosteroids such as cortisol and catecholamine such as epinephrine (adrenaline) and norepinephrine (noradrenaline).
They also release androgens. The adrenal glands can involve kidney function through the secretion of aldosterone, a hormone secreted in regulating the osmolarity of blood plasma. The adrenal glands are sited in the retro-peritoneum superior to the kidneys. They are located bilaterally. The combined weight of the adrenal glands in an adult human varies from 7 to 10grams. They are enclosed by an adipose capsule and renal fascia.
Each adrenal gland has two distinct structures, the outer adrenal cortex and the inner medulla, both of which secrete hormones. The cortex mainly secretes cortisol, aldosterone and androgens while the medulla chiefly secretes epinephrine and norepinephrine. Unlike the direct innervations of the medulla, the cortex is controlled by neuroendocrine hormones secreted from the pituitary gland which are regulated by the hypothalamus, and by the renin-angiotensin system.
Both of its regions are centers of formation of some vitally important hormones, having specific functions. Each adrenal gland weighs about 4 g and locates in close proximity to a kidney. The adrenal glands are sited in the posterior abdomen, between the superomedial kidney and the diaphragm. They are retroperitoneal, with parietal peritoneum enveloping their anterior surface only. The right gland is triangular in shape, in contrast with the semi-lunar shape of the left gland.
Perinephric (or renal) fascia enfolds the adrenal glands and the kidneys. This fascia binds the glands to the crura of the diaphragm. They are divided from the kidneys by the peri-renal fat. The adrenal glands exist in close proximity to many other structures in the abdomen:The adrenal glands comprise an outer connective tissue capsule, a cortex and a medulla. Veins and lymphatics leave each gland through the hilum, but arteries and nerves go into the glands at numerous sites.
Functionally, the cortex can be categorized into 3 regions (superficial to deep):1. Zona glomerulosa - forms and secretes mineralocorticoids such as aldosterone.2. Zona fasciculata - forms and secretes corticosteroids such as cortisol. It also produces a small amount of androgens.3. Zona reticularis - forms and secretes androgens such as dehydroepiandrosterone (DHES). It also produces a small amount of corticosteroids.
MedullaThe medulla is present in the center of the gland, and is dark brown in color. It has chromaffin cells, which release catecholamines (such as adrenaline) into the bloodstream in reaction to stressThe causes of adrenal disorders are:1. Malfunctioning of the pituitary gland, which leads to the inability of the pituitary gland to instruct and control the adrenal gland2. Tumors in the adrenal gland3.
Infections in the adrenal gland4. Impact of certain medications or steroids5. Genetic factorsX-rays, CT, MRI and Ultrasound imaging help diagnose possible tumors and other signs of disease. The ACTH stimulation test may be done to diagnose some of these disorders. The treatment of adrenal disorders is aimed at normalizing the adrenal hormone levels in the body. TABLE OF CONTENTIntroductionChapter 1 The Adrenal Gland...