Editing Endocrine system (section)

{{Short description|Hormone-producing glands of a body}}
{{Use American English|date=March 2019}}
{{Use mdy dates|date=March 2019}}
{{Infobox anatomy
| Name        = Endocrine system
| Latin       = systema endocrinum
| Image       = File:Endocrine_English.svg
| Caption     = Main [[Endocrine gland|glands]] of the human endocrine system
| Width       =
| Image2      =
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The '''endocrine system'''<ref>{{Cite web |date=2019-11-19 |title=Anatomy of the Endocrine System |url=https://www.hopkinsmedicine.org/health/wellness-and-prevention/anatomy-of-the-endocrine-system |access-date=2022-06-14 |website=www.hopkinsmedicine.org |language=en}}</ref> is a messenger system in an [[organism]] comprising [[feedback loop]]s of [[hormone]]s that are released by internal [[gland]]s directly into the [[circulatory system]] and that target and regulate distant [[Organ (biology)|organs]]. In [[vertebrate]]s, the [[hypothalamus]] is the neural control center for all endocrine systems.

In [[humans]], the major [[endocrine gland]]s are the [[thyroid gland|thyroid]], [[parathyroid gland|parathyroid]], [[pituitary gland|pituitary]], [[pineal gland|pineal]], and [[adrenal gland]]s, and the (male) [[testis]] and (female) [[ovaries]]. The [[hypothalamus]], [[pancreas]], and [[thymus]] also function as endocrine glands, among other functions. (The hypothalamus and pituitary glands are organs of the [[Neuroendocrinology#Neuroendocrine system|neuroendocrine system]]. One of the most important functions of the hypothalamus{{mdash}}it is located in the [[brain]] adjacent to the pituitary gland{{mdash}}is to link the endocrine system to the [[nervous system]] via the pituitary gland.) Other organs, such as the [[kidneys]], also have roles within the endocrine system by secreting certain hormones. The study of the endocrine system and its disorders is known as [[endocrinology]].
The [[thyroid gland|thyroid]] secretes [[thyroxine]], the [[pituitary gland|pituitary]] secretes [[growth hormone]], the [[pineal gland|pineal]] secretes [[melatonin]], the testis secretes [[testosterone]], and the [[ovaries]] secrete [[estrogen]] and [[progesterone]].<ref>{{Cite book |last=Gardner, Shoback |title=Greenspan's Basic and Clinical Endocrinology |publisher=McGraw Hill / Medical |year=2017 |isbn=978-1259589287 |edition=10th |pages=49–68}}</ref>

[[Gland|Glands]] that signal each other in sequence are often referred to as an axis, such as the [[hypothalamic–pituitary–adrenal axis]]. In addition to the specialized endocrine organs mentioned above, many other organs that are part of other body systems have secondary endocrine functions, including [[bone]], [[kidney]]s, [[liver]], [[heart]] and [[gonad]]s. For example, the kidney secretes the endocrine hormone [[erythropoietin]]. Hormones can be amino acid complexes, [[steroid]]s, [[eicosanoid]]s, [[leukotriene]]s, or [[prostaglandin]]s.<ref name="Marieb" />

The endocrine system is contrasted both to [[exocrine glands]], which secrete hormones to the outside of the body, and to the system known as  [[paracrine signalling]] between cells over a relatively short distance. Endocrine glands have no [[Duct (anatomy)|ducts]], are vascular, and commonly have intracellular vacuoles or granules that store their hormones. In contrast, exocrine glands, such as [[salivary gland]]s, [[mammary gland]]s, and [[submucosal glands]] within the [[Human gastrointestinal tract|gastrointestinal tract]], tend to be much less vascular and have ducts or a hollow [[Lumen (anatomy)|lumen]].
Endocrinology is a branch of [[internal medicine]].<ref name="Marieb">{{cite book |last=Marieb |first=Elaine |name-list-style=vanc |title=Anatomy & physiology |publisher=Pearson Education, Inc |location=Glenview, IL |year=2014 |isbn=978-0-321-86158-0}}</ref>