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.
Other examples of peptide hormones that stimulate nonpolar hormone release are the gonadotropins (FSH and LH) that control gonadal steroid secretion, and thyroid stimulating hormone (TSH) that controls thyroid hormone secretion.Recall that endocrine secretion is whatever occurs to increase the amount of hormone in the circulation). An example is the hormone adrenocorticotropic hormone (ACTH) that stimulates secretion of the steroid hormone cortisol by cells of the zona fasciculata in the adrenal cortex.