1 The phenotype may change constantly throughout the life of an individual because of environmental changes and the physiological and morphological changes associated with aging.
One special group of hormones is the tropic hormones that stimulate the hormone production of other endocrine glands. For example, thyroid-stimulating hormone (TSH) causes growth and increased activity of another endocrine gland, the thyroid, which increases output of thyroid hormones. hormone (from Greek á½ÏÎ¼Î®, impetus) is any member of a class of signaling molecules produced by glands in multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behaviour.
When these hormones drop below a particular level this stimulates the hypothalamus to release hormones. These hormones travel to the pituitary gland, acting as the signal to the pituitary gland to produce one or more of its hormones. The hormones produced by the pituitary gland are released into the bloodstream. The bloodstream transports the pituitary hormones to other endocrine glands, such as the thyroid gland. The pituitary gland hormones may then stimulate their target endocrine glands to produce their own hormones. These locally produced hormones do the actual work of regulating your body. Take the example of the control of thyroid hormones from the thyroid gland in your neck.