The adrenal glands are located at the top of each kidney. There are two parts: the medulla, which secretes the neurotransmitters norepinephrine, epinephrine and dopamine, and the cortex, which secrets glucocorticoids (cortisol), mineralcorticoids and androgens (sex hormones). Combined, these are referred to as adrenocorticoids. Exposure to prolonged stress leads to adrenal stress and adrenal insufficiency. The adrenals cannot produce enough adrenocortical hormones, and the entire body is affected. Loss of adrenal function can cause death.
Adrenals and Stress Response
Donna D. Ignatavicius, MS RN, and M. Linda Workman, Ph.D, authors of "Medical-Surgical Nursing: Critical Thinking for Collaborative Care," explain that the adrenocortical hormones produced by the adrenal glands play vital roles in the human stress response. When a real or perceived stress is experienced, a complex whole-body response is initiated in the brain and supported by the adrenal glands. Stressors can be physical, such as illness or trauma, or psychological and emotional.
Adrenal Neurotransmitters
The neurotransmitter epinephrine is released during a stress response. Epinephrine works on the sympathetic nervous system, which controls heart rate, breathing rate and blood pressure. Epinephrine also causes vasoconstriction, or narrowing of blood vessels, to help increase blood flow to vital organs and muscles. It causes the pupils to dilate to improve vision. All of these responses help you when you have to fight or flee a danger.
Adrenal Steroid Hormones
The most abundantly produced glucocorticoid is cortisol. During stress, the adrenal glands release high levels of cortisol to help the body turn protein, glucose and fat into energy. This affect fuels the fight-or-flight response. Cortisol also has important anti-inflammatory effects and enhances immune system function, two properties crucial to healing and overall well-being. Cortisol is essential to life.
Adrenal Stress
Dan Colbert, M.D. and author of "Stress Less," discusses how adrenal stress refers to a state of overproduction of adrenocortical hormones by the adrenal glands. Adrenal stress arises when, after prolonged exposure to stress, the body becomes adapted to the abnormally high levels of stress hormones and can no longer regulate cortisol production. The adrenal glands continue high output of these stress hormones. This causes a multitude of health problems similar to those found in Cushing's syndrome, a rare disease that affects the adrenal glands. High blood pressure, sleep problems, diabetes, depression, fatigue, truncal obesity and osteoporosis are the consequences of continuously elevated cortisol levels.
Adrenal Insufficiency
Adrenal insufficiency is a condition in which the adrenal glands don't produce enough adrenocortical hormones. Adrenal insufficiency can become life-threatening in its most severe form, known as Addison's disease. At this point, epinephrine and cortisol levels have dropped dramatically. This typically occurs over an extended period, but in some cases adrenal insufficiency can happen very rapidly. Exhaustion, low blood glucose levels referred to as hypoglycemia, and low blood pressure are reported by those suffering adrenal insufficiency. Other effects include difficulty concentrating and possibly confusion, depression, recurrent infections from immune system impairment, indigestion, weight gain and loss of muscle mass.
References
- "Medical-Surgical Nursing: Critical Thinking for Collaborative Care"; Donna D. Ignatavicius MS RN, & M. Linda Workman Ph.D; 2006
- "Stress Less"; Dan Colbert, MD; 2008
