Anterior pituitary

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Anterior pituitary

The anterior pituitary (also called the adenohypophysis, from Greek adeno, "gland"; hypo, "under"; physis, "growth"; hence, glandular undergrowth) comprises the anterior lobe of the pituitary glandPituitary gland

The pituitary gland, or hypophysis, is an endocrine gland about the size of a pea that sits in the small, bony cavity ...
and is part of the endocrine systemFacts About Endocrine system

The endocrine system is a control system of ductless glands that secrete chemical "instant messengers" called hormones that ...
. Unlike the posterior lobePosterior pituitary Summary

The posterior pituitary comprises the posterior lobe of the pituitary gland and is part of the endocrine system....
, the anterior lobe is genuinely glandular, hence the root adeno in its name.

Under the influence of the hypothalamusHypothalamus

The hypothalamus is a region of the mammalian brain located below the thalamus, forming the major portion of the ventral re...
, the anterior pituitary produces and secretes several peptide hormonePeptide hormone

Peptide hormones are a class of peptides that are secreted into the blood stream and have endocrine functions in living anim...
s that regulate many physiological processes including stressStress (medicine)

In medicine, stress is defined as one of the following:...
, growthGrowth

Growth can mean increase in spatial number or complexity for concrete entities in time or increase in some other dimension f...
, and reproduction.

Regions

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 three regions:

pars distalis ("distal part") - the majority of the anterior pituitary
pars tuberalisPars tuberalis

The pars tuberalis is part of the anterior lobe of the pituitary gland, and wraps the pituitary stalk in a highly vasculariz...
("tubular part") - a sheath extending up from the pars distalis and wrapping around the pituitary stalkPituitary stalk

The pituitary stalk, also known as the infundibular stalk or simply the infundibulum is the connection between the hypothala...
pars intermediaPars intermedia

Pars intermedia is the boundary between the anterior and posterior lobes of the pituitary....
("intermediate part") - sits between the bulk of the anterior pituitary and the posterior pituitary and is often very small in humans

The function of the tuberalis is not well characterized, and most of the rest of this article refers primarily to the distalis.

Embryology

Unlike the posterior pituitaryPosterior pituitary Summary

The posterior pituitary comprises the posterior lobe of the pituitary gland and is part of the endocrine system....
(pars nervosa), which originates from neural ectodermEctoderm

The ectoderm is the start of a tissue that covers the body surfaces....
, the anterior pituitary arises from an invaginationInvagination

Invagination means to fold inward or to sheath....
of the oral ectodermEctoderm

The ectoderm is the start of a tissue that covers the body surfaces....
and forms the Rathke's pouchRathke's pouch

In embryogenesis, Rathke's pouch is a depression in the roof of the developing mouth in front of the buccopharyngeal membran...
.

This differentiation is exhibited by the fact that while the posterior pituitaryPosterior pituitary

The posterior pituitary comprises the posterior lobe of the pituitary gland and is part of the endocrine system....
merely secretes hormones produced in the hypothalamusHypothalamus

The hypothalamus is a region of the mammalian brain located below the thalamus, forming the major portion of the ventral re...
, the anterior pituitary actually produces its hormones, while being under control of the hypothalamusFacts About Hypothalamus

The hypothalamus is a region of the mammalian brain located below the thalamus, forming the major portion of the ventral re...
.

Major hormones secreted

Hormone	Other names	Symbol(s)	Secretory cells (staining type)	Target	Effect
Adrenocorticotropic hormoneAdrenocorticotropic hormone Adrenocorticotropic hormone is a polypeptide hormone synthesised from POMC, and secreted from corticotropes in the anterio...	Corticotropin	ACTH	Corticotrophs	Adrenal glandAdrenal gland In mammals, the adrenal glands are the triangle-shaped endocrine glands that sit atop the kidneys; their name indicates tha...	Secretion of glucocorticoidGlucocorticoid Glucocorticoids are a class of steroid hormones characterised by an ability to bind with the cortisol receptor and trigger s... s
EndorphinEndorphin Endorphins are endogenous opioid biochemical compounds.... s	-	-	-	Opioid receptor	Inhibit perception of pain
Follicle-stimulating hormoneFollicle-stimulating hormone Follicle stimulating hormone is a hormone synthesised and secreted by gonadotropes in the anterior pituitary gland....	-	FSH	Gonadotrophs (basophil)	Ovaries, Testes	Growth of reproductive systemReproductive system A reproductive system is the ensembles and interactions of organs and/or substances within an organism that strictly pertain...
Human growth hormoneHuman growth hormone Human growth hormone can refer to:...	Somatotropin	hGH, STH	Somatotrophs	LiverLiver The liver is an organ in vertebrates, including humans.... , adipose tissueAdipose tissue Adipose tissue is an anatomical term for loose connective tissue composed of adipocytes....	Promotes growth; lipidLipid Lipids are a class of hydrocarbon-containing organic compounds essential for the structure and function of living cells.... & carbohydrateCarbohydrate Carbohydrates are chemical compounds that contain oxygen, hydrogen, and carbon atoms.... metabolismMetabolism Metabolism is the biochemical modification of chemical compounds in living organisms and cells....
Luteinizing hormoneLuteinizing hormone Luteinizing hormone is a hormone synthesized and secreted by gonadotropes in the anterior lobe of the pituitary gland....	Lutropin	LH, ICSH	Gonadotrophs (basophil)	Ovaries, Testes	Sex hormone production
ProlactinProlactin Prolactin is a peptide hormone synthesised and secreted by lactotrope cells in the adenohypophysis....	-	PRL	LactotrophLactotroph Summary Lactotrophs are cells in the anterior pituitary which produce prolactin in response to signals including dopamine and estrog... s, also known as Mammotrophs	OvariesOvary Ovaries are egg-producing reproductive organs found in female organisms. ... , mammary glandMammary gland Mammary glands are the organs that, in the female mammal, produce milk for the sustenance of the young.... s	Secretion of estrogenEstrogen Estrogens are a group of steroid compounds, named for their importance in the oestrus cycle, functioning as the primary fem... s/progesteroneProgesterone Progesterone is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy and embryogenesis of humans and ot... ; milkMilk Milk is the nutrient fluid produced by the mammary glands of female mammals .... production
Thyroid-stimulating hormoneThyroid-stimulating hormone Thyroid-stimulating hormone is a hormone synthesized and secreted by thyrotrope cells in the anterior pituitary gland which ...	Thyrotropin	TSH	Thyrotrophs (basophil)	Thyroid gland	Secretion of thyroid hormoneThyroid hormone The thyroid hormones, thyroxine and triiodothyronine, are tyrosine-based hormones produced by the thyroid gland.... s

Hypothalamic releasing and release-inhibiting factors

Hormone secretion from the anterior pituitary gland is regulated by hormones secreted by the hypothalamusHypothalamus

The hypothalamus is a region of the mammalian brain located below the thalamus, forming the major portion of the ventral re...
. Neuroendocrine neurons in the hypothalamus project axonAxon

An axon, or nerve fiber, is a long slender projection of a nerve cell, or neuron, that conducts electrical impulses aw...
s to the median eminenceMedian eminence

The median eminence is part of the inferior boundary for the hypothalamus part of the human brain....
, at the base of the brain. At this site, these neurons can release substances into small blood vessels that travel directly to the anterior pituitary gland (the hypothalamo-hypophysial portal vessels).

Name	Other Names	Abbreviations	Location	>- \| Corticotropin-releasing hormoneCorticotropin-releasing hormone Corticotropin-releasing hormone, originally named corticotropin-releasing factor, and also called corticoliberin...	Corticotropin-releasing factor, Corticoliberin	CRH, CRF	parvocellularParvocellular Parvocellular can refer to:* Parvocellular part... neuroendocrine neurons in the paraventricular nucleusParaventricular nucleus The paraventricular nucleus is an aggregation of neurons in the hypothalamus, adjacent to the third ventricle....	with vasopressinVasopressin Summary Arginine vasopressin, also known as argipressin or antidiuretic hormone, is a human hormone that is mainly relea... , stimulates secretion of ACTHAdrenocorticotropic hormone Adrenocorticotropic hormone is a polypeptide hormone synthesised from POMC, and secreted from corticotropes in the anterio... \|- \| DopamineFacts About Dopamine Dopamine is a chemical naturally produced in the body....	Prolactin-inhibiting hormone	DA, PIH	neuroendocrine neurons of the arcuate nucleusArcuate nucleus The arcuate nucleus is an aggregation of neurons in the mediobasal hypothalamus, adjacent to the third ventricle and the med...	inhibits secretion of prolactinProlactin Prolactin is a peptide hormone synthesised and secreted by lactotrope cells in the adenohypophysis.... \|- \| Gonadotropin-releasing hormoneGonadotropin-releasing hormone Gonadotropin-releasing hormone 1 is a peptide hormone responsible for the release of FSH and LH from the anterior pituitary....	Luteinising-hormone releasing hormone	GnRH, LHRH	neuroendocrine neurons in the medial preoptic and arcuate nucleiArcuate nucleus The arcuate nucleus is an aggregation of neurons in the mediobasal hypothalamus, adjacent to the third ventricle and the med...	stimulates secretion of LHLuteinizing hormone Luteinizing hormone is a hormone synthesized and secreted by gonadotropes in the anterior lobe of the pituitary gland.... and FSHFollicle-stimulating hormone Follicle stimulating hormone is a hormone synthesised and secreted by gonadotropes in the anterior pituitary gland.... \|- \| Growth hormone-releasing hormone	Growth-hormone-releasing factor, somatocrinin	GHRH, GHRF, GRF	arcuate nucleus neuroendocrineNeuroendocrine Neuroendocrine cells are a specialized group of nerve cells that produce hormones.... neurons	stimulates secretion of growth hormoneGrowth hormone Growth hormone is a polypeptide hormone synthesised and secreted by the anterior pituitary gland which stimulates growth and... \|- \| SomatostatinSomatostatin Somatostatin is a hormone comprising two peptides, one built of 14 amino acids, the other of 28 amino acids....	Growth hormone-inhibiting hormone, Somatotropin release-inhibiting factor	SS, GHIH, SRIF	neuroendocrine neurons of the periventricular nucleusPeriventricular nucleus The Periventricular nucleus is a composite structure of the hypothalamus....	inhibits secretion of growth hormoneGrowth hormone Growth hormone is a polypeptide hormone synthesised and secreted by the anterior pituitary gland which stimulates growth and... \|- \| Thyrotropin-releasing hormoneThyrotropin-releasing hormone Thyrotropin-releasing hormone, also called thyrotropin-releasing factor, thyroliberin or protirelin, is a ...	Thyrotropin-releasing factor, Thyroliberin, Protirelin	TRH, TRF	parvocellular neuroendocrine neurons in the paraventricularParaventricular nucleus The paraventricular nucleus is an aggregation of neurons in the hypothalamus, adjacent to the third ventricle.... and anterior hypothalamic nucleiAnterior hypothalamic nucleus The Anterior hypothalamic nucleus is a nucleus of the hypothalamus. ...	stimulates secretion of TSHThyroid-stimulating hormone Thyroid-stimulating hormone is a hormone synthesized and secreted by thyrotrope cells in the anterior pituitary gland which ... \|- \| VasopressinVasopressin Overview Arginine vasopressin, also known as argipressin or antidiuretic hormone, is a human hormone that is mainly relea...	Arginine vasopressin, Antidiuretic hormone, Argipressin	AVP, ADH	parvocellularParvocellular Overview Parvocellular can refer to:* Parvocellular part... neuroendocrine neurons in the paraventricular nucleusParaventricular nucleus The paraventricular nucleus is an aggregation of neurons in the hypothalamus, adjacent to the third ventricle....	with Corticotropin-releasing hormoneCorticotropin-releasing hormone Overview Corticotropin-releasing hormone, originally named corticotropin-releasing factor, and also called corticoliberin... , stimulates secretion of ACTHAdrenocorticotropic hormone Adrenocorticotropic hormone is a polypeptide hormone synthesised from POMC, and secreted from corticotropes in the anterio...

Anterior pituitary

Regions

Embryology

Major hormones secreted

Hypothalamic releasing and release-inhibiting factors

Additional images

See also

External links