Pituitary gland 57925 225160794 2008-07-12T05:40:53Z Doceva 7463522 /* Anterior pituitary (Adenohypophysis) */ {{Nofootnotes|date=June 2008}}{{Infobox Anatomy | Name = {{PAGENAME}} | Latin = hypophysis, glandula pituitaria | GraySubject = 275 | GrayPage = 1275 | Image = Gray1180.png | Caption = 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. | Image2 = Gray1181.png | Caption2 = Median sagittal through the hypophysis of an adult monkey. Semidiagrammatic. | Precursor = neural and oral [[ectoderm]], including [[Rathke's pouch]] | System = | Artery = [[superior hypophyseal artery]], [[infundibular artery]], [[prechiasmal artery]], [[inferior hypophyseal artery]], [[capsular artery]], [[artery of the inferior cavernous sinus]]<ref>{{cite journal | author = Gibo H, Hokama M, Kyoshima K, Kobayashi S | title = [Arteries to the pituitary] | journal = Nippon Rinsho | volume = 51 | issue = 10 | pages = 2550–4 | year = 1993 | pmid = 8254920}}</ref>| Vein = | Nerve = | Lymph = | MeshName = Pituitary+Gland | MeshNumber = A06.407.747 | DorlandsPre = h_22 | DorlandsSuf = 12439692 | }} The '''pituitary gland''', or '''hypophysis''', (from Greek hupophuein, to grow up beneath<ref>[http://www.thefreedictionary.com/hypophysis Information about hypophysis in the free online English dictionary and encyclopedia. <!-- Bot generated title -->]</ref>) is an [[endocrine gland]] about the size of a [[pea]]. It is a protrusion off the bottom of the [[hypothalamus]] at the base of the [[brain]], and rests in a small, bony cavity ([[sella turcica]]) covered by a [[Dura mater|dural]] fold ([[diaphragma sellae]]). 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 [[hormone]]s regulating [[homeostasis]], including [[trophic hormone]]s 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, pars intermedia, 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|Anterior pituitary}} The [[anterior pituitary]] synthesizes and secretes important endocrine hormones, such as [[Adrenocorticotropic Hormone|ACTH]], [[Thyroid stimulating hormone|TSH]], [[prolactin|PRL]], [[growth hormone|GH]], [[endorphin]]s, [[Follicle stimulating hormone|FSH]], and [[Leutinizing hormone|LH]]. These hormones are released from the anterior pituitary under the influence of [[hypothalamus]]. Hypothalamic hormones are secreted to the anterior lobe by way of a special capillary system, called the [[hypothalamic-hypophyseal portal system]]. ===Posterior pituitary (Neurohypophysis)=== {{main|Posterior pituitary}} The hormones secreted by the posterior pituitary are *[[Oxytocin]], where the majority is released from the [[paraventricular nucleus]] in the [[hypothalamus]] *[[Antidiuretic hormone]] (ADH, also known as [[vasopressin]] and AVP, arginine vasopressin), the majority of which is released from the [[supraoptic nucleus]] in the [[hypothalamus]] Oxytocin is one of the few hormones to create a positive feedback loop. For example, 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 an [[Pars intermedia|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: * [[Human development (biology)|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==<!-- This section is linked from [[Pituitary gland disorders]] --> Disorders involving the pituitary gland include: {| class="wikitable" | '''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 || any [[pituitary]] [[hormone]] |- | [[Pituitary adenoma]] || overproduction || any pituitary hormone |- | [[Hypopituitarism]] || underproduction || any pituitary hormone |} ==Additional images== <gallery> Image:Pituitary gland.png|Location of the pituitary gland in the human brain Image:Illu pituitary pineal glands.jpg|Pituitary and pineal glands Image:Gray516.png|The arteries of the base of the brain. Image:Gray715.png|Mesal aspect of a brain sectioned in the median sagittal plane. Image:Gray994.png|Sagittal section of nose mouth, pharynx, and larynx. </gallery> ==See also== * [[Head and neck anatomy]] ==References== <references/> ==External links== * {{BrainInfo|hier|382}} * {{BUHistology|14201loa}} * [http://www.umm.edu/endocrin/pitgland.htm The Pituitary Gland, from the UMM Endocrinology Health Guide] *[http://www.cvm.okstate.edu/instruction/mm_curr/histology/HistologyReference/HREndo.htm Oklamoma State, Endocrine System] * Pituitary apoplexy mimicking pituitary abscess [[http://www.ispub.com/ostia/index.php?xmlPrinter=true&xmlFilePath=journals/ijns/vol4n1/pituitary.xml]] {{pituitary_gland}} {{endocrine_system}} [[Category:Glands]] [[Category:Endocrine system]] [[Category:Head and neck]] [[Category:Neuroendocrinology]] {{Diencephalon}} [[af:Hipofise]] [[ar:غدة نخامية]] [[bn:পিটুইটারি গ্রন্থি]] [[bs:Hipofiza]] [[bg:Хипофиза]] [[ca:Hipòfisi]] [[cs:Hypofýza]] [[da:Hypofyse]] [[de:Hypophyse]] [[dv:ޕިޓޫއިޓަރީ ގްލޭންޑް]] [[et:Ajuripats]] [[es:Hipófisis]] [[eo:Hipofizo]] [[fr:Hypophyse]] [[hr:Hipofiza]] [[id:Hipofisis]] [[is:Heiladingull]] [[it:Ipofisi]] [[he:בלוטת יותרת המוח]] [[la:Glandula pituitaria]] [[lt:Hipofizė]] [[hu:Agyalapi mirigy]] [[mk:Хипофиза]] [[nl:Hypofyse]] [[ja:下垂体]] [[no:Hypofyse]] [[pl:Przysadka mózgowa]] [[pt:Hipófise]] [[ru:Гипофиз]] [[sq:Hipofiza]] [[simple:Pituitary gland]] [[sk:Podmozgová žľaza]] [[sl:Hipofiza]] [[sr:Хипофиза]] [[sh:Hipofiza]] [[fi:Aivolisäke]] [[sv:Hypofys]] [[te:పియూష గ్రంధి]] [[th:ต่อมใต้สมอง]] [[tr:Hipofiz]] [[uk:Гіпофіз]] [[zh:腦下垂體]]