pituitary

Information about pituitary



Located at the base of the brain, the pituitary gland is protected by a bony structure called the sella turcica(also known as turkish saddle)of the sphenoid bone.

Median sagittal through the hypophysis of an adult monkey. Semidiagrammatic.
Latin	hypophysis, glandula pituitaria
	subject #275 1275
Artery	superior hypophyseal artery, infundibular artery, prechiasmal artery, inferior hypophyseal artery, capsular artery, artery of the inferior cavernous sinus^[1]
Precursor	neural and oral ectoderm, including Rathke's pouch
MeSH	Pituitary+Gland
Dorlands/Elsevier	h_22/12439692

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. The pituitary fossa, in which the pituitary gland sits, is situated in the sphenoid bone in the middle cranial fossa at the base of the brain.

The pituitary gland secretes hormones regulating homeostasis, including trophic hormones that stimulate other endocrine glands. It is functionally connected to the hypothalamus by the median eminence.

The hypophysis is also the top cell of the suspensor in a dicot embryo, which will differentiate to form part of the root cap.

Sections

Located at the base of the brain, the pituitary is functionally linked to the hypothalamus. It is composed of two lobes: the adenohypophysis and neurohypophysis. The adenohypophysis, also referred to as the anterior pituitary is divided into anatomical regions known as the pars tuberalis and pars distalis. The neurohypophysis, also referred to as the posterior pituitary. The pituitary is functionally linked to the hypothalamus by the pituitary stalk, whereby hypothalamic releasing factors are released and in turn stimulate the release of pituitary hormones.

Anterior pituitary (Adenohypophysis)

Main article: Anterior pituitary

The anterior lobe is derived from the oral ectoderm and is composed of glandular epithelium. The anterior pituitary is functionally linked to the hypothalamus via the hypophysial-portal vascular connection in the pituitary stalk. Through this vascular connection the hypothalamus integrates stimulatory and inhibitory central and peripheral signals to the five phenotypically distinct pituitary cell types.

The anterior pituitary synthesizes and secretes important endocrine hormones, such as ACTH, TSH, prolactin, growth hormone, endorphins, FSH, and LH. These hormones are released from the anterior pituitary under the influence of hypothalamic hormones. The hypothalamic hormones travel to the anterior lobe by way of a special capillary system, called the hypothalamic-hypophyseal portal system.

Posterior pituitary (neurohypophysis)

Main article: Posterior pituitary

The posterior lobe is connected to the hypothalamus via the infundibulum or pituitary stalk, giving rise to the tuberoinfundibular pathway. Hormones are made in nerve cell bodies positioned in the hypothalamus, and these hormones are then transported down the nerve cell's axons to the posterior pituitary.

The hormones secreted by the posterior pituitary are

Oxytocin which is released from the paraventricular nucleus in the Hypothalamus
Antidiuretic hormone (ADH, also known as vasopressin and AVP, arginine vasopressin), is released from the supraoptic nucleus in the Hypothalamus

Oxytocin is the only pituitary hormone to create a positive feedback loop. For example, when the cervix dilates the uterus contracts. Uterine contractions stimulate the release of oxytocin from the posterior pituitary, which in turn increases uterine contractions. This positive feedback loop continues until the baby is born.

Intermediate lobe

There is also a intermediate lobe in many animals. For instance in fish it is believed to control physiological colour change. In adult humans it is just a thin layer of cells between the anterior and posterior pituitary. The intermediate lobe produces melanocyte-stimulating hormone (MSH), although this function is often (imprecisely) attributed to the anterior pituitary.

Functions

The pituitary hormones help control some of the following body processes:

Growth
Blood pressure
Some aspects of pregnancy and childbirth including stimulation of uterine contractions during childbirth
Breast milk production
Sex organ functions in both women and men
Thyroid gland function
The conversion of food into energy (metabolism)
Water and osmolarity regulation in the body.

Pathology

Disorders involving the pituitary gland include:

Condition	Direction	Hormone
Acromegaly	overproduction	growth hormone
Growth hormone deficiency	underproduction	growth hormone
Syndrome of inappropriate antidiuretic hormone	overproduction	vasopressin
Diabetes insipidus	underproduction	vasopressin
Sheehan syndrome	underproduction	prolactin
Pituitary adenoma	overproduction	any pituitary hormone
Hypopituitarism	underproduction	any pituitary hormone

Additional images

Location of the pituitary gland in the human brain	Pituitary and pineal glands	The arteries of the base of the brain.
Mesal aspect of a brain sectioned in the median sagittal plane.	Sagittal section of nose mouth, pharynx, and larynx.

References

1. ^ Gibo H, Hokama M, Kyoshima K, Kobayashi S (1993). "[Arteries to the pituitary]". Nippon Rinsho 51 (10): 2550-4. PMID 8254920.

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] Human anatomy, endocrine system: endocrine glands
Hypothalamic/pituitary axes	Adrenal axis (Adrenal gland) • Thyroid axis (Thyroid gland, Parathyroid gland) • Gonadal axis (Testes, Ovaries, Corpus luteum)
Other	Pineal gland • Islets of pancreas

• • [ 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

In animals, the brain or encephalon (Greek for "in the skull"), is the control center of the central nervous system, responsible for behavior. The brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing,
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The Sella turcica (literally ) is a saddle-shaped depression in the sphenoid bone at the base of the human skull.

The seat of the saddle is known as the hypophyseal fossa which holds the pituitary gland. Located anteriorly to the hypophyseal fossa is the tuberculum sellae.
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The sphenoid bone (from Greek sphenoeides, "wedgelike") is a bone situated at the base of the skull in front of the temporals and basilar part of the occipital bone.

The sphenoid bone somewhat resembles a butterfly or bat with its wings extended.
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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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Arteries are muscular blood vessels that carry blood away from the heart.^[1] All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.

The circulatory system is extremely important for sustaining life.
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The superior hypophysial artery is an artery supplying the pars tuberalis and infundibulum of the pituitary gland. It is a branch of the internal carotid artery.^[1]

References

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The inferior hypophysial artery is an artery supplying the pituitary gland. It is a branch of the cavernous carotid artery.^[1]

References

1. ^ Gibo H, Hokama M, Kyoshima K, Kobayashi S (1993).

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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 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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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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Endocrine glands are glands that secrete their product directly into the blood rather than through a duct. This group contains the glands of the Endocrine system.

External links

Endocrine+glands at eMedicine Dictionary

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PEA can stand for:

Phenylethylamine
Pea plant
Phillips Exeter Academy
Pulseless electrical activity (a form of cardiac arrest)
Prenatal exposure to alcohol
Phenylethyl Alcohol Agar
Polyadic equality algebras (See also Cylindric algebras (CA))

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The dura mater (from the Latin "hard mother"), or pachymeninx, is the tough and inflexible outermost of the three layers of the meninges surrounding the brain and spinal cord. (The other two meningeal layers are the pia mater and the arachnoid mater.
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The middle fossa, deeper than the anterior cranial fossa, is narrow in the middle, and wide at the sides of the skull.

It is bounded in front by the posterior margins of the small wings of the sphenoid, the anterior clinoid processes, and the ridge forming the anterior
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hormone (from Greek όρμή - "to set in motion") is a chemical messenger that carries a signal from one cell (or group of cells) to another. All multicellular organisms produce hormones (including plants - see phytohormone).
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Homeostasis is the property of either an open system or a closed system, especially a living organism, to regulate the state of its internal environment so as to maintain a stable, constant condition.
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Tropic hormones are anterior pituitary-secreted hormones that regulate the activity of various endocrine glands.

One example is the thyroid-stimulating hormone (TSH) (produced by the anterior pituitary) and stimulates the thyroid gland to secrete thyroid hormones.
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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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The median eminence is part of the inferior boundary for the hypothalamus part of the human brain. A small swelling on the tuber cinereum posterior to the infundibulum - atop the pituitary stalk - the median eminence
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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.
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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 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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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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EnglishInfo

pituitary

Information about pituitary

Sections

Anterior pituitary (Adenohypophysis)

Posterior pituitary (neurohypophysis)

Intermediate lobe

Functions

Pathology

Additional images

See also

References

External links

References

References

What forms from it (general)?

What forms from it (vertebrates)?

External links

Anatomy

Anatomy

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