Endocrine+System

__**Endocrine System**__ The Endocrine system regulates the body's activities by producing chemicals that control the body's daily activities. It also regulates long-term changes such as growth and developement. This is all possible through __glands__, or organs that produce/release chemical(s). Endocrine glands produce and release their chemical products directly into the blood stream. These glands respond to changes in the environment detected by the nervous system. The chemical product is called a __hormone.__ A hormone will: turn on, turn off, speed up, or slow down activities of organs. An organ will only be affected by the hormone if it has the specific __target cells__. Target cells are cells that recognize a hormones structure.

__**Glands of the Endocrine System:**__
 * Hypothalamus**- links the nervous and the endocrine systems and controls the pituitary gland. (small; located in the center of the brain)
 * Pituitary Gland**- controls other endocrine glands and regulates growth, blood pressure, and water balance. (small; located below hypothalamus)
 * Thymus**- hormones from this gland help the immune system develop during childhood (located infront of heart)
 * Adrenal Glands(2)**- release several hormones. Adrenaline triggers the body's response to emergency situations (fight or flight). Other homones afect salt and water balance in the kidneys and sugar in the blood. (located above kidneys)
 * Thyroid**- controls the release of energy from food molecules inside cells (metabolism). (located near larynx)
 * Parathroid Glands(4)-** regulate the amount of calcium in the blood. (very small; located on thyroid gland)
 * Pancreas-** produces the hormones insulin and glucagon, which control the level of glucose in the blood. (fairly large; located infront of kidneys)
 * Testes(2)-** release the sex hormone testosterone, which controls changes in a male's body and regulates sperm production. (external organs; located in male reproductive system)
 * Ovaries(2)-** release female sex hormones. Estrogen controls changes in a female's body. Estrogen and progesterone trigger egg develope ment. (internal organs; located in remale reproductive system)[[image:Endocrine_System.gif]]