Over 50 hormones have been identified in humans and other vertebrates. Hormones control or regulate many biological processes and are often produced in exceptionally low amounts within the body. Examples of such processes include:. Much like a lock and key, many hormones act by binding to receptors that are produced within cells. When a hormone binds to a receptor, the receptor carries out the hormone's instructions, either by altering the cell's existing proteins or turning on genes that will build a new protein.
The hormone-receptor complex switches on or switches off specific biological processes in cells, tissues, and organs.
The endocrine system, made up of all the body's different hormones, regulates all biological processes in the body from conception through adulthood and into old age, including the development of the brain and nervous system, the growth and function of the reproductive system, as well as the metabolism and blood sugar levels. The female ovaries, male testes, and pituitary, thyroid, and adrenal glands are major constituents of the endocrine system.
Hypothalamus - The hypothalamus links our endocrine and nervous systems together. The hypothalamus drives the endocrine system. Pituitary gland - The pituitary gland receives signals from the hypothalamus. This gland has two lobes, the posterior and anterior lobes. The endocrine system is a complex network of glands and organs. The following are integral parts of the endocrine system:. Pineal body. The pineal body is located below the corpus callosum, in the middle of the brain. It produces the hormone melatonin, which helps the body know when it's time to sleep.
The pituitary gland is located below the brain. Patients are usually referred to endocrinologists by their primary doctors. To become an endocrinologist , a student needs to attend college as well as complete a degree in internal medicine before they specialize in endocrinology. In the U. Live Science. Jump to: Endocrine system function Endocrine system diseases What is an endocrinologist?
Additional resources. Located on the tops of the kidneys, these glands produce steroid hormones such as corticosterone, which helps regulate the body's stress response and maintain homeostasis. The pituitary gland is a small bean-shaped gland at the base of the brain.
It links the endocrine system and nervous system. Nerve cells in the hypothalamus make chemicals that control the release of hormones secreted from the pituitary gland. The hypothalamus gathers information sensed by the brain such as the surrounding temperature, light exposure, and feelings and sends it to the pituitary.
This information influences the hormones that the pituitary makes and releases. Pituitary: The pituitary pronounced: puh-TOO-uh-ter-ee gland is at the base of the brain, and is no bigger than a pea. Despite its small size, the pituitary is often called the "master gland. The pituitary also secretes endorphins pronounced: en-DOR-fins , chemicals that act on the nervous system and reduce feelings of pain.
The pituitary also secretes hormones that signal the reproductive organs to make sex hormones. The pituitary gland also controls ovulation and the menstrual cycle in women. Thyroid: The thyroid pronounced: THY-royd is in the front part of the lower neck. It's shaped like a bow tie or butterfly. These hormones control the rate at which cells burn fuels from food to make energy. The more thyroid hormone there is in the bloodstream, the faster chemical reactions happen in the body.
Thyroid hormones are important because they help kids' and teens' bones grow and develop, and they also play a role in the development of the brain and nervous system. Parathyroids: Attached to the thyroid are four tiny glands that work together called the parathyroids pronounced: par-uh-THY-roydz. They release parathyroid hormone, which controls the level of calcium in the blood with the help of calcitonin pronounced: kal-suh-TOE-nin , which the thyroid makes.
The adrenal glands have two parts, each of which makes a set of hormones and has a different function:.
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