anterior pituitary

Information about anterior pituitary



Pituitary gland. (Most of the orange region is "pars distalis", but the part at the top is "pars tuberalis".)

Median sagittal through the hypophysis of an adult monkey. Semidiagrammatic.
Latin	lobus anterior hypophyseos
	subject #275 1275
Precursor	oral mucosa (Rathke's pouch)
MeSH	Anterior+Pituitary+Gland
Dorlands/Elsevier	a_14/12111161

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

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.

Regions

The term "pars distalis" is sometimes used as a synonym for the 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 tuberalis ("tubular part") - a sheath extending up from the pars distalis and wrapping around the pituitary stalk
pars intermedia ("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 pituitary (pars nervosa), which originates from neural ectoderm, the anterior pituitary arises from an invagination of the oral mucosa called Rathke's pouch (which is itself ectoderm derived).

This differentiation is exhibited by the fact that while the posterior pituitary merely secretes those hormones produced in the hypothalamus (ADH and oxytocin), the anterior pituitary actually produces its hormones, while being under control of the hypothalamus as to when they should be secreted.

Major hormones secreted

Hormone	Other names	Symbol(s)	Secretory cells (staining type)	Target	Effect
Adrenocorticotropic hormone	Corticotropin	ACTH	Corticotrophs (basophil)	Adrenal gland	Secretion of glucocorticoids
Endorphins	-	-	-	-	Inhibit perception of pain
Follicle-stimulating hormone	-	FSH	Gonadotrophs (basophil)	Ovaries, Testes	Growth of reproductive system
Growth hormone	Somatotropin	GH, STH	Somatotrophs (acidophil)	Liver, adipose tissue	Promotes growth; lipid & carbohydrate metabolism
Luteinizing hormone (females), Interstitial Cell Stimulating Hormone (males)	Lutropin	LH, ICSH	Gonadotrophs (basophil)	Ovaries, Testes	Sex hormone production
Prolactin	-	PRL	Lactotrophs, also known as Mammotrophs (acidophil)	Ovaries, mammary glands	Secretion of estrogens/progesterone; milk production
Thyroid-stimulating hormone	Thyrotropin	TSH	Thyrotrophs (basophil)	Thyroid gland	Secretion of thyroid hormones

A useful acronym for the hormones secreted by the anterior pituitary is 'FLAT PEG' (FSH, LH, ACTH, TSH, Prolactin, Endorphins, GH).

Hypothalamic releasing and release-inhibiting factors

Hormone secretion from the anterior pituitary gland is regulated by hormones secreted by the hypothalamus. Neuroendocrine neurons in the hypothalamus project axons to the median eminence, 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	Function
Corticotropin-releasing hormone	Corticotropin-releasing factor, Corticoliberin	CRH, CRF	parvocellular neuroendocrine neurons in the paraventricular nucleus	with vasopressin, stimulates secretion of ACTH
Dopamine	Prolactin-inhibiting hormone	DA, PIH	neuroendocrine neurons of the arcuate nucleus	inhibits secretion of prolactin
Gonadotropin-releasing hormone	Luteinising-hormone releasing hormone	GnRH, LHRH	neuroendocrine neurons in the medial preoptic and arcuate nuclei	stimulates secretion of LH and FSH
Growth hormone-releasing hormone	Growth-hormone-releasing factor, somatocrinin	GHRH, GHRF, GRF	arcuate nucleus neuroendocrine neurons	stimulates secretion of growth hormone
Somatostatin	Growth hormone-inhibiting hormone, Somatotropin release-inhibiting factor	SS, GHIH, SRIF	neuroendocrine neurons of the periventricular nucleus	inhibits secretion of growth hormone
Thyrotropin-releasing hormone	Thyrotropin-releasing factor, Thyroliberin, Protirelin	TRH, TRF	parvocellular neuroendocrine neurons in the paraventricular and anterior hypothalamic nuclei	stimulates secretion of TSH
Vasopressin	Arginine vasopressin, Antidiuretic hormone, Argipressin	AVP, ADH	parvocellular neuroendocrine neurons in the paraventricular nucleus	with Corticotropin-releasing hormone, stimulates secretion of ACTH

Additional images

The anterior pituitary is the anterior, glandular lobe of the pituitary gland.

External links

• • [ e] Endocrine system > Pituitary gland
Posterior pituitary	Pars nervosa - Median eminence - Infundibular stalk
Anterior pituitary	Pars intermedia - Pars tuberalis - Pars distalis - Acidophils (Somatotropes, Lactotropes) - Basophils (Corticotropes, Gonadotropes, Thyrotropes)

• • [ e] Brain: diencephalon
Epithalamus	Pineal body • Habenula (Habenular nuclei)
Hypothalamus	anterior: Anterior hypothalamic nucleus • Paraventricular nucleus • Preoptic area • Supraoptic nucleus • Suprachiasmatic nucleus intermediate/middle/tuberal/pituitary: infundibulum • median eminence • arcuate nucleus • Ventromedial nucleus • Dorsomedial hypothalamic nucleus • Tuber cinereum, Pituitary gland (Anterior pituitary, Posterior pituitary) posterior/lateral: posterior nucleus • Mammillary body • Lateral nucleus other: Medial forebrain bundle
Subthalamus	Subthalamic nucleus • Zona incerta • Thalamic fasciculus • Lenticular fasciculus
Thalamus/nuclei	Ventral nuclear group (VA/VL, VP/VPM/VPL) • MD • AN • LNG (Pulvinar) • Intralaminar nucleus (Centromedian nucleus) • Midline nuclear group • Thalamic reticular nucleus • Metathalamus (MG, LG) • Interthalamic adhesion
Third ventricle	recesses: (Optic recess, Infundibular recess, Suprapineal recess, Pineal recess) • Hypothalamic sulcus
Other	Interventricular foramina • Optic chiasm • Subfornical organ • Mammillothalamic tract

Latin}}}
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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Embryology is the study of the development of an embryo. An embryo is defined as any vertebrate in a stage before birth or hatching. Embryology refers to the development of the egg cell (zygote) after fertilization and the differentiation of cells into tissues and organs.
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The oral mucosa is the mucous membrane epithelium of the mouth. It can be divided into three categories.

Masticatory mucosa - keratinized stratified squamous epithelium, found on the dorsum of the tongue, hard palate and attached gingiva.

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In embryogenesis, Rathke's pouch is a depression in the roof of the developing mouth in front of the buccopharyngeal membrane. The pouch eventually loses its connection with the pharynx giving rise to the anterior pituitary.
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Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed
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Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
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The pituitary gland, or hypophysis, is an endocrine gland about the size of a pea that sits in a small, bony cavity (sella turcica) covered by a dural fold (sellar diaphragm) at the base of the brain.
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1. Pineal gland 2. Pituitary gland 3. Thyroid gland 4. Thymus 5. Adrenal gland 6. Pancreas 7. Ovary 8. Testes]]

The endocrine system
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The posterior pituitary (or neurohypophysis) comprises the posterior lobe of the pituitary gland and is part of the endocrine system.

Anatomy

The Posterior Pituitary Gland
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The hypothalamus links the nervous system to the endocrine system via the pituitary gland (hypophysis). The hypothalamus, (from Greek ὑποθαλαμος = under the thalamus) is located below the thalamus, just above the brain stem.
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Peptide hormones are a class of peptides that are secreted into the blood stream and have endocrine functions in living animals.

Like other proteins, peptide hormones are synthesized from amino acids according to an mRNA template, which is itself synthesized from a DNA
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Growth refers to an increase in some quantity over time. The quantity can be physical (e.g., growth in height, growth in an amount of money) or abstract (e.g., a system becoming more complex, an organism becoming more mature). It can also refer to the mode of growth, i.e.
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The pars tuberalis is part of the anterior lobe of the pituitary gland, and wraps the pituitary stalk in a highly vascularized sheath.

External links

Pars+tuberalis at eMedicine Dictionary
UIUC Histology Subject 9
NeuroNames

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Also see infundibulum for other uses of the term.

The pituitary stalk (also known as the infundibular stalk or simply the infundibulum) is the connection between the hypothalamus and the posterior pituitary.
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Pars intermedia is the boundary between the anterior and posterior lobes of the pituitary. It contains three types of cells - basophils, chromophobes, and colloid-filled cysts. The cysts are the remainder of Rathke’s pouch.
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The posterior pituitary (or neurohypophysis) comprises the posterior lobe of the pituitary gland and is part of the endocrine system.

Anatomy

The Posterior Pituitary Gland
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The ectoderm is the start of a tissue that covers the body surfaces. It emerges first and forms from the outermost of the germ layers.

What forms from it (general)?

Nervous system
Outer part of integument

What forms from it (vertebrates)?

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Invagination means to fold inward or to sheath. In biology, this can refer to a number of processes.

(1) Invagination is the morphogenetic processes by which an embryo takes form, and is the initial step of gastrulation, the massive reorganization of the embryo from a simple
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The oral mucosa is the mucous membrane epithelium of the mouth. It can be divided into three categories.

Masticatory mucosa - keratinized stratified squamous epithelium, found on the dorsum of the tongue, hard palate and attached gingiva.

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The posterior pituitary (or neurohypophysis) comprises the posterior lobe of the pituitary gland and is part of the endocrine system.

Anatomy

The Posterior Pituitary Gland
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Arginine vasopressin (AVP), also known as argipressin or antidiuretic hormone (ADH), is a hormone found in most mammals, including humans. One of its most important roles is to regulate the body's retention of water, being released when the body is
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Oxytocin (ŏk'sĭ-tō'sĭn) (Greek: "quick birth") is a mammalian hormone that also acts as a neurotransmitter in the brain. In females, it is released in large amounts after distension of the cervix and vagina during labor, and after stimulation of the
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Adrenocorticotropic hormone (ACTH or corticotropin) is a polypeptide hormone produced and secreted by the pituitary gland. It is an important player in the hypothalamic-pituitary-adrenal axis.
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Corticotropes (or corticotrophs) are cells in the anterior pituitary which produce adrenocorticotrophic hormone and melanocyte stimulating hormone.

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EnglishInfo

anterior pituitary

Information about anterior pituitary

Regions

Embryology

Major hormones secreted

Hypothalamic releasing and release-inhibiting factors

Additional images

See also

External links

Anatomy

External links

Anatomy

What forms from it (general)?

What forms from it (vertebrates)?

Anatomy

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