The endocrine system controls the production and secretion of hormones. Hormones control growth, sexual development, metabolism and other body functions. This system consists of the pituitary gland, hypothalamus, thyroid gland, pineal body, adrenal glands, parathyroid glands and the pancreas. The pituitary gland acts as the master gland because it produces hormones that play a role in the function of other endocrine system glands. This gland produces growth hormone, adrenocorticotropin, thyroid-stimulating hormone, luteinizing hormone, vasopressin, prolactin and oxytocin.
The hypothalamus regulates metabolism, feelings of fullness after eating and body temperature. This gland also secretes hormones that control the release of hormones from the pituitary gland. The thyroid gland produces hormones that regulate metabolism. This gland also participates in growth and development of the nervous system, blood pressure regulation, digestion, reproduction, muscle tone and regulation of the heart rate. The pineal body secretes melatonin, which helps regulate the sleep cycle.
The adrenal glands, located at the top of each kidney, consist of the adrenal medulla and adrenal cortex. The adrenal cortex produces corticosteroids to regulate fluid-salt balance, immune system function, metabolism and sexual function. The adrenal medulla produces hormones that control the body’s response to stress. The parathyroid glands control calcium levels in the blood and bones. The pancreas secretes digestive enzymes and secretes glucagon and insulin. Insulin and glucagon control the amount of glucose in the blood, so damage to the pancreas can lead to diabetes.