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.
In this way, it initiates the menstrual cycle. The pituitary gland, also known as the hypophysis, is a small gland connected to the hypothalamus by a stalk (called the infundibulum). The pituitary has 2 major lobes: the posterior and anterior.1  The posterior lobe is nerve tissue, and is really a downgrowth of the hypothalamus. Since it is a part of the brain, and made of nervous tissue, it has direct nervous influence. 2  It activates, controls and integrates the autonomic nervous system, and. 3  since it also acts as a gland, it's endocrine activity produces and secretes certain hormones and releasing factors.