{{Infobox Anatomy |
Name = {{PAGENAME}} |
Latin = glandula suprarenalis |
GraySubject = 277 |
GrayPage = 1278 |
Image = illu_endocrine_system.jpg |
Caption = [[Endocrine system]] |
Image2 = Illu adrenal gland.jpg |
Caption2 = Adrenal gland |
System = Endocrine |
Artery = [[superior suprarenal artery]], [[middle suprarenal artery]], [[Inferior suprarenal artery]] |
Vein = [[suprarenal veins]] |
Nerve = [[celiac plexus]], [[renal plexus]] |
Lymph = [[lumbar glands]] |
MeshName = Adrenal+Glands |
MeshNumber = A06.407.071 |
DorlandsPre = g_06 |
DorlandsSuf = 12392729 |
}}

In [[mammal]]s, the '''adrenal glands''' (also known as '''suprarenal glands''') are the triangle-shaped [[endocrine gland]]s that sit on top of the [[kidney]]s; their name indicates that position (''ad-'', "near" or "at" + ''-renes'', "kidneys"). They are chiefly responsible for regulating the [[stress (medicine)|stress]] response through the [[synthesis]] of [[corticosteroid]]s and [[catecholamine]]s, including [[cortisol]] and [[adrenaline]].

==Anatomy and function==
Anatomically, the adrenal glands are located in the thoracic abdomen situated atop the [[kidney]]s, specifically on their anterosuperior aspect. In humans, the adrenal glands are found at the level of the 12th [[thoracic vertebra]] and receive their blood supply from the [[adrenal artery|adrenal arteries]].

The adrenal gland is separated into two distinct structures, both of which receive regulatory input from the [[nervous system]]:

*[[Adrenal medulla]]
*:As its name suggests, the [[adrenal medulla]] is the central core of the adrenal gland, surrounded by the adrenal cortex. The [[chromaffin cells]] of the medulla are the body's main source of the [[catecholamine]] hormones [[adrenaline]] (epinephrine) and [[noradrenaline]] (norepinephrine). These water-soluble hormones, derived from the amino acid [[tyrosine]], are part of the [[fight-or-flight response]] initiated by the [[sympathetic nervous system]]. The adrenal medulla can be considered specialized ganglia of the [[sympathetic nervous system]], lacking distinct synapses, instead releasing secretions directly into the blood. It is also the main source of [[dopamine]], a [[catecholamine]] closely related to adrenaline and noradrenaline.

*[[Adrenal cortex]]
*:By contrast, the [[adrenal cortex]] is devoted to the synthesis of [[corticosteroid]] [[hormones]] from [[cholesterol]]. Some cells belong to the [[hypothalamic-pituitary-adrenal axis]] and are the source of [[cortisol]] synthesis. Other cortical cells produce [[androgen]]s such as [[testosterone]], while some regulate [[water]] and [[electrolyte]] concentrations by secreting [[aldosterone]]. In contrast to the direct innervation of the medulla, the cortex is regulated by [[neuroendocrine]] hormones secreted by the [[pituitary gland]] and [[hypothalamus]], as well as by the [[renin-angiotensin system]].

===Arteries and veins===
Although variations of the blood supply to the adrenal glands (and indeed the kidneys themselves) are common, there are usually three arteries that supply each adrenal gland:
* The [[superior suprarenal artery]] is provided by the [[inferior phrenic arteries|inferior phrenic]]
* The [[middle suprarenal artery]] is provided by the [[abdominal aorta]]
* The [[inferior suprarenal artery]] is provided by the [[renal artery]]

[[Venous]] drainage of the adrenal glands is achieved via the [[suprarenal veins]]:
* The [[right suprarenal vein]] drains into the [[inferior vena cava]]
* The [[left suprarenal vein]] drains into the left [[renal vein]] or the left [[inferior phrenic vein]].

The [[suprarenal veins]] receive blood may form [[anastomoses]] with the [[inferior phrenic veins]].

The adrenal glands and the [[thyroid gland]] are the organs that have the greatest blood supply per gram of tissue. Up to 60 arterioles may enter each adrenal gland.<ref>JE Skandalakis. Surgical Anatomy: The Embryologic And Anatomic Basis Of Modern Surgery (2004).</ref>

==See also==
*[[Fight-or-flight response]]
*[[Stress (medicine)|Stress]]
*[[Geoffrey Bourne (anatomist)|Geoffrey Bourne]]

==References==
===Notes===
<references/>

===General references===
* {{MedlinePlus|002219}}
* {{IowaHistologyInteractive|272}}
* {{AnatomyAtlasesMicroscopic|15|292}} - "Adrenal Gland"
* {{BUHistology|14501loa}}
* {{SUNYAnatomyLabs|40|03|01|05}} - "Posterior Abdominal Wall: The Retroperitoneal Fat and Suprarenal Glands"
* [http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/adrenal/index.html Adrenal Gland], from Colorado State University
* {{ViennaCrossSection|pembody/body8a}}

{{Endocrine system}}
{{Adrenal gland}}

[[Category:Glands]]
[[Category:Abdomen]]
[[Category:Endocrine system]]

[[bn:অ্যাড্রিনাল গ্রন্থি]]
[[bg:Надбъбречна жлеза]]
[[bs:Nadbubrežna žlijezda]]
[[ca:Glàndula adrenal]]
[[cs:Nadledvina]]
[[da:Binyre]]
[[de:Nebenniere]]
[[dv:އެޑްރީނަލް ގްލޭންޑް]]
[[es:Glándula suprarrenal]]
[[eo:Surrena glando]]
[[fr:Glande surrénale]]
[[hr:Nadbubrežna žlijezda]]
[[id:Kelenjar adrenal]]
[[ia:Glandula adrenal]]
[[it:Surrene]]
[[he:בלוטת יותרת הכליה]]
[[la:Glandula adrenalis]]
[[lt:Antinkstis]]
[[mk:Надбубрежна жлезда]]
[[nl:Bijnier]]
[[ja:副腎]]
[[no:Binyre]]
[[pl:Nadnercze]]
[[pt:Glândula supra-renal]]
[[ru:Надпочечники]]
[[simple:Adrenal gland]]
[[fi:Lisämunuainen]]
[[sv:Binjure]]
[[te:అధివృక్క గ్రంధి]]
[[th:ต่อมหมวกไต]]