Medical Questions » Hormones Questions » Question No. 521
| Question: | Could you explain the function of the adrenal glands and their connection to adrenalin? |
| Answer: | The adrenal glands are part of the system that produces the body' s hormones (called the endocrine system). They sit on top of each kidney, a bit like a beanie. The glands are tiny—less than 5 cm long and weigh only a few grams—and yet produce more than three dozen hormones. The glands are divided into two quite distinct parts—an inner, reddish brown section called the medulla and an outer, yellow-coloured section called the cortex. Each part has its own distinct function.
The hormones produced by the medulla in the adrenal gland include adrenalin, which causes the well-known ' fight or flight' response to danger. The medulla is part of the autonomic (unconscious) nervous system, and when the body becomes aware of danger through one of its senses, these hormones literally spurt out making the heart beat faster, increasing the blood sugar level, altering the blood flow and generally increasing the body' s capacity to deal with the emergency. Because many of the stresses of modern life do not require such a physical response, the release of adrenalin is sometimes inappropriate and the body has no way of using it up. If it happens too often it may eventually cause health problems.
The hormones produced by the cortex are steroids, of which there are three main groups. One group controls the balance of minerals in the body. Another group regulates the use the body makes of carbohydrates, and also plays a part in our ability to handle stress (cortisone is the most important hormone of this group). The third group affects the operation of our sex glands and influences our sexual development. Steroids are made from cholesterol, so a certain amount of cholesterol is necessary in our diet, provided it isn' t more than we need, which can cause heart problems.
Like other glands in the endocrine system, the adrenal cortex is controlled by the pituitary gland, which sits under the brain.
If the adrenal glands are destroyed because of disease (eg. tuberculosis or cancer) or are overactive, the functioning of our entire body can be impaired. The most common disorders are called Addison' s disease and Cushing' s syndrome.
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