Adrenal glands (also known as suprarenal glands) are an important part of a human endocrine system. They are situated on top of each kidney. These glands are responsible for creating numerous hormones that are necessary for a healthy life. The suprarenal glands are made up of two different parts:
- The adrenal cortex: It is the outer part of the gland which produces hormones that are crucial to life, like cortisol (regulates metabolism and helps body cope with stress) and aldosterone (controls blood pressure).
- The adrenal medulla: It is the inner part of the gland which produces hormones like adrenaline (helps body respond to stress).
One thing that may click your mind when you think of adrenal glands (also referred to as suprarenal glands) is stress. You’re right because adrenal glands secrete hormone adrenaline, which quickly prepares your body to fight a stressful situation. But these glands contribute to your health even when you not under stress. In fact, they produce hormones which are necessary for you to live.
Hormones of the Adrenal Glands
The adrenal medulla and the adrenal cortex function distinctly. One of the main differences between them is that adrenal cortex hormones are necessary for life, while adrenal medulla hormones are not.
Adrenal Cortex Hormones
The adrenal cortex secretes two kinds of corticosteroid hormones, mineralcorticoids and glucocorticoids. The secretion of glucocorticoids is prompted by the pituitary gland
. Similarly, secretion of mineralcorticoids is triggered by the signals from the kidney. When the hypothalamus produces CRH (corticotrophin-releasing hormone), it directs the pituitary gland to discharge ACTH
(adrenal corticotrophic hormone). These glands further stimulate the adrenal glands to produce adequate amount of corticosteroid hormones.
Two types of glucocorticoids released by the adrenal cortex contain:
- Hydrocortisone: Known as cortisol in the medical dictionary, this hormone is responsible for regulating how the body converts, fats, proteins and carbohydrates into energy. It is also essential for controlling blood pressure and cardiovascular function.
- Corticosterone: This hormone works in coordination with hydrocortisone to conceal inflammatory reactions and control immune response.
Mineralcorticoids include aldosterone which maintains the balance of water and salt in the body and help control blood pressure.
There is another hormone released by the adrenal cortex, commonly known as sex hormones. Adrenal cortex releases little amount of male and female hormones but their impact is clouded by large amount of estrogen
Adrenal Medulla Hormones
Unlike its counterpart, adrenal medulla doesn’t perform crucial functions. But this does not mean it is useless. When you are under stress, the hormones of the adrenal medulla are released which stimulate the nervous system. It helps you deal with emotional and physical stress
. Hormones produced by the adrenal medulla include:
Diseases of the Adrenal Glands
- Epinephrine: Commonly called adrenaline, this hormone increases your heart rate and rushes blood to the muscles and brain at the time of stress. Moreover, it helps it increases your blood sugar level and converts glycogen to glucose in the liver.
- Norepinephrine: It works with epinephrine in responding to stress. However, it can cause vasoconstriction which may lead to high blood pressure.
There can be various reasons why adrenal glands do not work properly. One f the problems can be the gland itself. Following are the most common disorders of the adrenal glands
- Addison’s disease: This disorder develops when the adrenal cortex fails to produce enough cortisol and aldosterone. It can occur at any age and to anyone, from children to adults to older people.
- Adrenal cancer: Adrenal cancer is extremely rare but very dangerous. Destructive adrenal tumors tend to spread to other body parts and cause adverse changes because of excess production of hormones.
- Cushing’s syndrome: Cushing’s syndrome is not very common because it is caused by overproduction of the hormone cortisol. A tumor in the adrenal gland or pituitary gland could be blamed for Cushing’s syndrome.
The adrenal glands perform multiple functions in the endocrine system. Adrenal medulla and cortex are two different parts which take care of your body’s internal processes.