The adrenal gland is one of a number of hormone-producing organs that make up the endocrine system. Gary Thibodeau, PhD, author of the book, "The Human Body in Health and Disease," describes the adrenal gland as consisting of two individual endocrine glands: the adrenal cortex and the adrenal medulla. The medulla is the center of the adrenal gland, while the cortex is its outer layer. The cortex itself is divided into three layers, where three different types of corticoid hormone are produced.
Moon-shaped Face
The center layer of the adrenal cortex produces glucocorticoids, which include hormones such as cortisol that prompt the liver to create glucose. Glucocorticoids break down muscle proteins and fats into amino and fatty acids that the liver can use to create glucose.
When the adrenal cortex produces too much glucocorticoid, areas of fat are redistributed. The Children's Hospital of Pittsburgh notes that in the adrenal disorder known as Cushing's syndrome, this causes fat deposits to form that create a round faced appearance and a swollen "buffalo hump" between the shoulder blades.
High Blood Pressure
The outer layer of the adrenal cortex produces mineralocorticoids, hormones that control mineral salt levels in the blood. Aldosterone is the main mineralocorticoid, and it prompts the kidneys to reabsorb sodium into the blood that otherwise would be lost in the urine. Simultaneously, the aldosterone effect causes the secretion of potassium into the urine. The increase in sodium levels causes the kidneys to reabsorb water as well and blood pressure rises.
The American Cancer Society lists high blood pressure as a symptom of high aldosterone levels as well as high cortisol levels, both of which can result from a functioning tumor of the adrenal glands.
Decreased Immunity
The tendency to get sick frequently and recover slowly may indicate the presence of and adrenal cortex disorder. Cortisol in high concentrations acts to reduce the body's inflammatory response, in part by suppressing the immune system, according to Chris Doumen, PhD, professor of biology at Collin College in Texas.
When the adrenal gland produces elevated levels of glucocorticoid, increased blood concentrations of the hormone can cause the thymus gland to atrophy, according to Thibodeau. The thymus gland is mainly composed of white blood cells, and is a vital element in the body's ability to fight infection. Atrophy decreases its ability to perform its normal function and a decrease in immunity can ensue.
References
- Collin College: Anatomy/Physiology: Major Endocrine Organs
- American Cancer Society: How is Adrenal Cancer Found?
- The Human Body in Health and Disease; Gary Thibodeau, PhD and Kevin Patton, PhD; 2002
- Children's Hospital of Pittsburgh: Overactive Adrenal Glands/Cushing's Syndrome
