Anterior pituitary: Difference between revisions
imported>Gareth Leng (New page: {{subpages}} The '''anterior pituitary''' (also called the adenohypophysis, from Greek adeno, "gland"; hypo, "under"; physis, "growth") is the anterior lobe of the pituitary gland. Under...) |
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The '''anterior pituitary''' (also called the adenohypophysis, from Greek adeno, "gland"; hypo, "under"; physis, "growth") is the anterior lobe of the pituitary gland. | The '''anterior pituitary''' (also called the adenohypophysis, from Greek adeno, "gland"; hypo, "under"; physis, "growth") is the anterior lobe of the pituitary gland. The term "pars distalis" is sometimes used as a synonym for the anterior pituitary, but this is not quite correct. The anterior pituitary is usually divided into the [[pars distalis]] ("distal part") comprising most of the anterior pituitary, and the [[pars tuberalis]] ("tubular part") - which extends up from the pars distalis and wraps around the pituitary stalk. | ||
Under the influence of the hypothalamus, the anterior pituitary produces and secretes several peptide hormones that regulate many physiological processes including stress, growth, and reproduction. | Under the influence of the hypothalamus, the anterior pituitary produces and secretes several peptide hormones that regulate many physiological processes including stress, growth, and reproduction. | ||
Cells of the anterior pituitary gland produce six major peptide [[hormone]]s. | |||
*[[Growth hormone]] is produced by [[somatotroph]] cells | |||
*[[Thyroid stimulating hormone]] (TSH) | |||
*[[Prolactin]] is produced by [[lactotroph]]s | |||
*[[Adrenocorticotrophic hormone]] (ACTH)is produced by [[corticotroph]]s | |||
*[[Luteinizing hormone]] (LH) and | |||
*[[Follicle stimulating hormone]] (FSH) are produced by [[gonadotroph]]s | |||
Hormone secretion from the anterior pituitary is mainly regulated by factors secreted from neuroendocrine neurons of the hypothalamus into the hypothalamo-hypophysial portal vessels from the nerve endings of neurosecretory neurons. | |||
The secretion of LH and FSH is regulated by [[Gonadotrophin releasing hormone]] (GnRH, also known as LH releasing hormone, LHRH). | |||
Growth hormone is regulated by an inhibitory factor, [[Somatostatin]] (from neurons of the periventricular nucleus) | |||
and by a stimulatory factor, [[Growth hormone releasing hormone]](from neurons of the [[arcuate nucleus]]) | |||
ACTH secretion is regulated by two synergistically interacting releasing -factors, [[Corticotrophin releasing hormone]] (CRH)(from neurons of the paraventricular nucleus]]), and [[vasopressin]] also released from parvocellular neurons of the [[paraventricular nucleus),(often from the same neurons that produce CRH) | |||
TSH secretion is regulated by [[Thyrotrophin releasing hormone]] (TRH)(from neurons of the [[paraventricular nucleus]]). Prolactin secretion is regulated by an inhibitory factor, [[dopamine]], released by neurons of the [[arcuate nucleus]] (the so-called tuberoinfundibular dopamine neurons). Prolactin release is also governed by a paracrine mechanism involving secretions from the pars tuberalis acting on the lactotrophs of the pars distalis. | |||
Revision as of 08:57, 11 April 2008
The anterior pituitary (also called the adenohypophysis, from Greek adeno, "gland"; hypo, "under"; physis, "growth") is the anterior lobe of the pituitary gland. The term "pars distalis" is sometimes used as a synonym for the anterior pituitary, but this is not quite correct. The anterior pituitary is usually divided into the pars distalis ("distal part") comprising most of the anterior pituitary, and the pars tuberalis ("tubular part") - which extends up from the pars distalis and wraps around the pituitary stalk.
Under the influence of the hypothalamus, the anterior pituitary produces and secretes several peptide hormones that regulate many physiological processes including stress, growth, and reproduction.
Cells of the anterior pituitary gland produce six major peptide hormones.
- Growth hormone is produced by somatotroph cells
- Thyroid stimulating hormone (TSH)
- Prolactin is produced by lactotrophs
- Adrenocorticotrophic hormone (ACTH)is produced by corticotrophs
- Luteinizing hormone (LH) and
- Follicle stimulating hormone (FSH) are produced by gonadotrophs
Hormone secretion from the anterior pituitary is mainly regulated by factors secreted from neuroendocrine neurons of the hypothalamus into the hypothalamo-hypophysial portal vessels from the nerve endings of neurosecretory neurons. The secretion of LH and FSH is regulated by Gonadotrophin releasing hormone (GnRH, also known as LH releasing hormone, LHRH).
Growth hormone is regulated by an inhibitory factor, Somatostatin (from neurons of the periventricular nucleus) and by a stimulatory factor, Growth hormone releasing hormone(from neurons of the arcuate nucleus) ACTH secretion is regulated by two synergistically interacting releasing -factors, Corticotrophin releasing hormone (CRH)(from neurons of the paraventricular nucleus]]), and vasopressin also released from parvocellular neurons of the [[paraventricular nucleus),(often from the same neurons that produce CRH) TSH secretion is regulated by Thyrotrophin releasing hormone (TRH)(from neurons of the paraventricular nucleus). Prolactin secretion is regulated by an inhibitory factor, dopamine, released by neurons of the arcuate nucleus (the so-called tuberoinfundibular dopamine neurons). Prolactin release is also governed by a paracrine mechanism involving secretions from the pars tuberalis acting on the lactotrophs of the pars distalis.