The endocrine system is a collection of glands that secrete hormones which control and regulate a variety of body functions such as metabolism, growth and development, body defenses, homeostasis, stress and injury response, and reproduction. Read this article to learn more about the endocrine system, including what hormones are, detailed information about different glands, and some disorders related to the endocrine system.
Hormones
Hormones are regulatory substances produced in an organism and transported in tissue fluids to stimulate specific cells or tissues into actions. They only affect certain target cells or tissues through either direct gene activation (lipid and cholesterol based) or secondary messenger system (protein based)
Hormone release is primarily controlled by negative feedback mechanisms. There are three mechanisms for hormonal release:
Humoral stimuli: in response to changes in extracellular fluid
Hormonal stimuli: in response to hormones being released by other glands
Neural stimuli: the nervous system directly stimulates the endocrine glands
Endocrine glands
Find information about the pituitary gland, the thyroid gland, and the pancreas. Keep in mind that these are not all the glands included in the endocrine system. They are just some examples.
Pituitary gland
The pituitary gland has a nickname “the master gland”. It is roughly the size of a grape and is located on the hypothalamus of the brain. The hormones released from the pituitary gland are controlled by the hypothalamus. There are two lobes: anterior and posterior (AKA anterior pituitary gland and posterior pituitary gland).
Thyroid gland
The thyroid gland controls the body’s metabolism, and it is located at the base of the throat. It secretes hormones such as Triiodothyronine (T3) and Thyroxine (T4), which are partially composed of iodine and control the rate at which glucose is burned. In addition, the thyroid gland also secretes calcitonin, which regulates calcium and phosphate levels in the blood by lowering it.
Pancreas
Pancreas is part of the endocrine system, but it also plays a role in the digestive system. It is located in the abdominal cavity near the stomach, and is mainly in charge of maintaining blood glucose levels. The pancreas secretes glucagon and insulin. Glucagon stimulates the liver to break down glycogen into glucose in order to raise the blood sugar concentration; insulin decreases blood sugar concentration by increasing the uptake of glucose by cells.
Related disorders
Some disorders related to the endocrine systems are introduced here.
Pancreas disorders - insulin related
Diabetes Mellitus, more commonly known as diabetes, is a result of insulin deficiency, which causes the blood sugar to rise. The excess is excreted through the urine. Signs of diabetes include excessive urination, excessive thirst, and hunger due to inability to use sugars. There are two types of diabetes - type I and type II. Type I diabetes is often caused by inherited immune disorders that destroy pancreatic cells, while type II diabetes is usually caused by weight and unhealthy diet. There is an additional type of diabetes called hypoglycemia, which occurs when blood sugar levels become too low, and can be cured by injection or eating sweet food.
Thyroid disorders
A disorder called Goiters is caused by a deficiency in iodine which results in swelling of the neck and thyroid gland. Iodine is found in seafood naturally or iodized salt.
Another disorder related to the thyroid is cretinism, which is caused by a lack of thyroid hormone in early childhood. It leads to dwarfism and mental retardation.
Hope this article helped you learn more about the human endocrine system. Thanks for reading!
Written by: Benetta Wang
Comments