Alguno no tenía claro esta tarde qué es lo que hace la Hipófisis:
Pituitary Gland (Hypophysis)
Neurohypophysis (Posterior Lobe of the Pituitary Gland)
The neurohypophysis consists of a meshwork of glia cells with numerous
capillaries. It does not itself secrete hormones but is solely the storage
and releasing organ for hormones formed in the hypothalamus, antidiuretic
hormone (vasopressin) and oxytocin. These reach the posterior
pituitary through nervous pathways (axons)—a process called neurosecretion—
and are then released into the bloodstream. Oxytocin contracts
smooth muscles (e. g., it promotes uterine contractions during
labor), while vasopressin promotes the reabsorption of water in the collecting
tubules of the kidney and so raises the blood pressure (increase in
Adenohypophysis (Anterior Lobe of the Pituitary Gland)
The anterior lobe consists of an irregular collection of glandular cells in
an extensive capillary bed. Release of anterior pituitary hormones is promoted
(liberins) or inhibited (statins) by the action of hypothalamic releasing
hormones, which reach the anterior lobe through the bloodstream.
Some anterior pituitary hormones are nonglandotropic or effector
hormones, i.e., they act directly on their target organs, rather than on a
peripheral endocrine gland serving as a relay. For example, growth hor-
mone, also called somatotropin (STH), stimulates bodily growth, while
prolactin (PRL) stimulates cell division and secretion of milk by the
mammary glands in late pregnancy and during the breastfeeding period.
The remaining anterior pituitary hormones stimulate subordinated
peripheral endocrine glands to grow as well as secrete and release their
hormones. These hormones may be divided into gonadotropins, which
act on the gonads, and nongonadotropic hormones, which influence the
activity of the adrenal and thyroid glands, for example.
The gonadotropins include follicle-stimulating hormone (FSH, follitropin)
and luteinizing hormone (LH, lutropin). Both act on the gonads of
men as well as women. FSH stimulates the maturation of the follicle in
the ovary and promotes spermatogenesis (development of sperm) in
men. LH acts on the interstitial cells of the ovary and the testes, initiating
ovulation in women and enhancing testosterone secretion in men.
The nongonadotropic hormones include corticotropin or adrenocorticotropic
hormone (ACTH) and thyrotropin or thyroid-stimulating hormone
(TSH, thyrotropin). Whereas ACTH acts to stimulate the adrenal cortex,
TSH stimulates the secretion of hormones by the thyroid gland.