Hypothalamic–pituitary hormone
   HOME

TheInfoList



OR:

Hypothalamic–pituitary hormones are
hormone A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required ...
s that are produced by the
hypothalamus The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
and
pituitary gland In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The ...
. Although the organs in which they are produced are relatively small, the effects of these hormones cascade throughout the body. They can be classified as a hypothalamic–pituitary axis (HP axis) of which the
adrenal The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex which ...
(),
gonad A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sper ...
al (),
thyroid The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thy ...
(), somatotropic (), and
prolactin Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pit ...
() axes are branches. It is possible for the function of these hormones to be altered by physical activity. In posterior pituitary we have hormones that control absorption of water and oxytocin. Anterior hypophysis, neurosecretory cells which release hormones. There is a pituitary portal system, with which the hormones are transported. These hormones are prolactin, growth hormone, TSH, adrenocorticotropic hormone, FSH and LH. They are all released by anterior pituitary. Some have targets in glands and some with direct function. Anterior pituitary is an amalgam of hormone producing glandular cells. There are conditions related to the limbic system which regulate the hormone release. And also thalamus, with pain. Many of these stimuli come from the senses of the subject. The temperature control can be found in the hypothalamus. There is also regulation of water balance. And also hunger, and also something associated with water balance control (ADH). ·      Corticotropic releasing hormone CRH: stimulates ACTH secretion ·      Thyrotropin releasing hormone (TRH): stimulates TSH and prolactin secretion ·      Growth hormone releasing hormone (GHRH): stimulates GH secretion ·      Somatostatin: inhibits GH (and other hormone) secretion ·      Gonadotropin releasing hormone (GnRH): stimulates FSH and LH secretion ·      Prolactin releasing hormone (PRH): stimulates PRL secretion ·      Prolactin inhibiting hormone (dopamine): inhibits PRL secretion These hypothalamic hormones are secreted in pulse. They act on specific membrane receptors. They are glycoproteins. Then you have the signal. They stimulate release of pituitary hormones. They stimulate synthesis of pituitary hormones, stimulate release stored pituitary hormones, stimulate hyperplasia and hypertrophy of target cells and regulate their own receptors. Anterior pituitary produces prolactin, GH, TSH, ACTH, FSH, LH. 15–20% of corticotroph cells, produce ACTH. The targets are the adrenal glands, adipocytes and melanocytes. 3–5% thyrotroph cells, produce TSH. 10–15%, Gonadotroph, produce LH and FSH 40–50% somatotroph, produce GH in particular in childhood. 10–15% lactotroph, produce prolactin.


References

Hormones of the hypothalamus Hormones of the pituitary gland Hormones of the hypothalamus-pituitary axis {{med-stub