There are numerous organs that excrete substances called hormones. Hormones are responsible for a host of bodily functions such as reproduction, bone growth and strength, and glucose utilization.
Pancreas and Diabetes Mellitus
One of the most common endocrine disorders is diabetes mellitus, which is the result of a lack of insulin production in Type I and abnormal forms of insulin, sometimes called insulin resistance (Type II). Insulin comes from specialized cells in the pancreas. Insulin drives blood glucose into the cells for use as fuel and storage. People with Type 1 develop it early in life and must take insulin injections while those who acquire it later in life (Type II) may take medications, insulin, or both. Weight loss and exercise can sometimes reverse Type II diabetes. There are serious consequences of poorly managed diabetes, such as neuropathy—painful sensations in the hands and feet. There can be kidney damage and failure leading to dialysis. People can get foot ulcers that won’t heal and may need an amputation. Blindness and heart disease are potential complications of diabetes as well.
Thyroid and Parathyroid Glands
Another common hormone comes from the thyroid gland, a two-lobed structure on the neck. Parathyroid glands are behind the wings of the thyroid gland.
The thyroid gland makes two thyroid hormones called T4 and T3 that are essential for metabolism. About every function in the body needs the thyroid to function, such as the following:
- Heart rate
- Menstrual cycles
- Muscle strength
- Nervous system
- Body temperature
- Cholesterol levels
Excess thyroid hormone is called hyperthyroidism, and lack of them is called hypothyroidism. Some signs of low levels of thyroid are fatigue, dry skin, constipation, hair loss, infertility. Excess hormones can cause an elevated pulse, facial flushing, excess sweating, diarrhea, and bulging eyes, to name a few.
The parathyroid glands primarily regulate calcium levels in the blood so that nerves and muscles can work properly.
The adrenal glands sit on top of the kidneys and have two functions. One is to produce steroids such as cortisol, sex steroids, aldosterone, and the other is fight or flight hormones; epinephrine and norepinephrine. Bone and muscle mass, hair growth, and water and salt balance are regulated by the adrenal glands.
The Pituitary and Hypothalamus
The pituitary and hypothalamus are in the brain and are the control centers for the glands outside of the brain. The hypothalamus sends hormones to the pituitary to tell it to release its hormones so that they can circulate and reach the end-organ like the thyroid, adrenals, ovaries, or testicles. Those pituitary hormones trigger the release of hormones from the individual organs. Once there are adequate circulating levels, the hypothalamus is notified to back off.