Editing Artery

{{short description|Blood vessels that carry blood away from the heart}}
{{redirect|Arteries|specific arteries|List of arteries of the human body}}
{{Other uses}}
{{Infobox anatomy
| Name        = Artery
| Latin       = arteria ([[plural]]: arteriae)
| Greek      = ἀρτηρία
| Image       = Artery.svg
| Caption     = Diagram of an artery
| Image2      = 
| Caption2    = 
| Precursor   = 
| System      = [[Circulatory system]]
| Artery      = 
| Vein        = 
| Nerve       = 
| Lymph       = 
}}
An '''artery''' ({{Etymology|gre|''ἀρτηρία'' (artēríā)}})<ref>[https://web.archive.org/web/20221012173429/https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Da%29rthri%2Fa ἀρτηρία], Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus</ref> is a [[blood vessel]] in humans and most other animals that takes [[oxygenated blood]] away from the [[heart]] in the [[systemic circulation]] to one or more parts of the body. Exceptions that carry [[deoxygenated blood]] are the [[pulmonary arteries]] in the [[pulmonary circulation]] that carry blood to the [[lung]]s for oxygenation, and the [[umbilical arteries]] in the [[fetal circulation]] that carry deoxygenated blood to the [[placenta]]. It consists of a multi-layered '''artery wall''' wrapped into a tube-shaped channel.

Arteries contrast with [[vein]]s, which carry deoxygenated blood back towards the heart; or in the pulmonary and fetal circulations carry oxygenated blood to the lungs and fetus respectively.

==Structure==
[[File:Blausen 0055 ArteryWallStructure.png|thumb|Microscopic anatomy of an artery]]
[[File:Artery.png|thumbnail|Cross-section of a human artery]]
{{See also|Arterial tree}}

The anatomy of arteries can be separated into [[gross anatomy]], at the [[macroscopic scale|macroscopic level]], and [[histology|microanatomy]], which must be studied with a [[microscope]]. The arterial system of the [[human body]] is divided into [[systemic circulation|systemic arteries]], carrying blood from the heart to the whole body, and [[pulmonary artery|pulmonary arteries]], carrying deoxygenated blood from the [[heart]] to the [[lung]]s.

Large arteries (such as the aorta) are composed of many different types of cells, namely endothelial, smooth muscle, fibroblast, and immune cells.<ref>{{Cite journal |last1=Scipione |first1=Corey A. |last2=Hyduk |first2=Sharon J. |last3=Polenz |first3=Chanele K. |last4=Cybulsky |first4=Myron I. |date=December 2023 |title=Unveiling the Hidden Landscape of Arterial Diseases at Single-Cell Resolution |url=https://linkinghub.elsevier.com/retrieve/pii/S0828282X2301663X |journal=Canadian Journal of Cardiology |language=en |volume=39 |issue=12 |pages=1781–1794 |doi=10.1016/j.cjca.2023.09.009|pmid=37716639 |url-access=subscription }}</ref> As with veins, the arterial wall consists of three layers called tunics, namely the ''[[tunica intima]]'', ''[[tunica media]]'', and ''[[tunica externa]]'', from innermost to outermost. The ''externa'', alternatively known as the ''tunica adventitia'', is composed of [[collagen]] fibers and [[elastic tissue]]—with the largest arteries containing [[vasa vasorum]], small blood vessels that supply the walls of large blood vessels.<ref name=":1">{{Cite web |last1=Steve|first1=Paxton|last2=Michelle|first2=Peckham|last3=Adele|first3=Knibbs|date=2003|title=The Leeds Histology Guide|url=https://www.histology.leeds.ac.uk/circulatory/arteries.php|language=en}}</ref> Most of the layers have a clear boundary between them, however the tunica externa has a boundary that is ill-defined. Normally its boundary is considered when it meets or touches the connective tissue.<ref>{{Cite book|title=Rutherford's Vascular Surgery and Endovascular Therapy|last=Sidawy|first=Anton|publisher=Elsevier, Inc.|year=2019|isbn=9780323427913|location=Amsterdam, Netherlands|pages=34–48}}</ref>  Inside this layer is the ''tunica media'', which is made up of [[smooth muscle]] cells, [[elastic tissue]] (also called ''connective tissue proper'') and [[collagen]] fibres.<ref name=":1" /> The innermost layer, which is in direct contact with the flow of blood, is the ''tunica intima''. The elastic tissue allows the artery to bend and fit through places in the body. This layer is mainly made up of [[endothelium|endothelial cell]]s (and a supporting layer of [[elastin]] rich [[collagen]] in elastic arteries). The hollow internal cavity in which the blood flows is called the [[lumen (anatomy)|lumen]].

===Development===
{{Further|Angiogenesis|Vasculogenesis}}
Arterial formation begins and ends when [[endothelial cell]]s begin to express arterial specific genes, such as [[EPH receptor B2|ephrin B2]].<ref>{{cite journal|last=Swift|first=MR|author2=Weinstein, BM|title=Arterial-venous specification during development.|journal=Circulation Research|date=Mar 13, 2009|volume=104|issue=5|pages=576–88|pmid=19286613|doi=10.1161/CIRCRESAHA.108.188805|doi-access=free}}</ref>

==Function==
[[File:Arterial System en.svg|thumbnail|Arteries form part of the human [[circulatory system]]]]
{{refimprove|section|date=May 2024}}
{{main|Circulatory system}}
Arteries form part of the [[circulatory system]]. They carry [[blood]] that is oxygenated after it has been pumped from the [[heart]]. [[Coronary circulation|Coronary arteries]] also aid the heart in pumping blood by sending oxygenated blood to the heart, allowing the muscles to function. Arteries carry oxygenated blood away from the heart to the tissues, except for [[pulmonary arteries]], which carry blood to the [[lung]]s for oxygenation (usually [[vein]]s carry deoxygenated blood to the heart but the [[pulmonary vein]]s carry oxygenated blood as well).<ref>{{cite book
| last = Maton
| first = Anthea
| author2 = Jean Hopkins
| author3 = Charles William McLaughlin
| author4 = Susan Johnson
| author5 = Maryanna Quon Warner
| author6 = David LaHart
| author7 = Jill D. Wright
| title = Human Biology and Health
| publisher = Prentice Hall
| year = 1999
| location = Englewood Cliffs, New Jersey
| url = https://archive.org/details/humanbiologyheal00scho
| isbn = 0-13-981176-1
| url-access = registration
}}</ref>  There are two types of unique arteries. The [[pulmonary artery]] carries blood from the heart to the [[lung]]s, where it receives oxygen. It is unique because the blood in it is not "oxygenated", as it has not yet passed through the lungs. The other unique artery is the [[umbilical artery]], which carries deoxygenated blood from a fetus to its mother.

Arteries have a [[blood pressure]] higher than other parts of the circulatory system. The pressure in arteries varies during the [[cardiac cycle]]. It is highest when the [[Systole (medicine)|heart contracts]] and lowest when [[diastole|heart relaxes]]. The variation in pressure produces a [[pulse]], which can be felt in different areas of the body, such as the [[radial pulse]]. [[Arterioles]] have the greatest collective influence on both local blood flow and on overall blood pressure. They are the primary "adjustable nozzles" in the blood system, across which the greatest pressure drop occurs. The combination of heart output ([[cardiac output]]) and [[systemic vascular resistance]], which refers to the collective resistance of all of the body's [[arteriole]]s, are the principal determinants of arterial blood pressure at any given moment.

Arteries have the highest pressure and have narrow lumen diameter.{{what|date=May 2024}}

[[Systemic circulation|Systemic arteries]] are the arteries (including the [[peripheral arteries]]), of the [[systemic circulation]], which is the part of the [[circulatory system|cardiovascular system]] that carries [[oxygen]]ated [[blood]] away from the heart, to the [[Human body|body]], and returns deoxygenated blood back to the heart. Systemic arteries can be subdivided into two types—muscular and elastic—according to the relative compositions of elastic and muscle tissue in their tunica media as well as their size and the makeup of the internal and external elastic lamina. The larger arteries (>10&nbsp; mm diameter) are generally elastic and the smaller ones (0.1–10&nbsp;mm) tend to be muscular. Systemic arteries deliver blood to the [[arterioles]], and then to the [[capillaries]], where nutrients and gasses are exchanged.

After traveling from the [[aorta]], blood travels through peripheral arteries into smaller arteries called [[arterioles]], and eventually to [[capillaries]]. [[Arterioles]] help in regulating [[blood pressure]] by the variable contraction of the [[Smooth muscle tissue|smooth muscle]] of their walls, and deliver blood to the [[capillaries]]. This smooth muscle contraction is primarily influenced by activity of the sympathetic vasomotor nerves innervating  the arterioles.<ref>{{Cite journal |last1=Aalkjær |first1=Christian |last2=Nilsson |first2=Holger |last3=De Mey |first3=Jo G. R. |date=2021-04-01 |title=Sympathetic and sensory-motor nerves in peripheral small arteries |url=https://journals.physiology.org/doi/10.1152/physrev.00007.2020 |journal=Physiological Reviews |language=en |volume=101 |issue=2 |pages=495–544 |doi=10.1152/physrev.00007.2020 |pmid=33270533 |s2cid=227282958 |issn=0031-9333|url-access=subscription }}</ref><ref>{{Cite journal |last1=Bruno |first1=Rosa Maria |last2=Ghiadoni |first2=Lorenzo |last3=Seravalle |first3=Gino |last4=Dell'Oro |first4=Raffaella |last5=Taddei |first5=Stefano |last6=Grassi |first6=Guido |date=2012 |title=Sympathetic regulation of vascular function in health and disease |journal=Frontiers in Physiology |volume=3 |page=284 |doi=10.3389/fphys.2012.00284 |pmid=22934037 |pmc=3429057 |issn=1664-042X |doi-access=free }}</ref> Enhanced  sympathetic activation prompts vasoconstriction, reducing the lumen diameter. A reduced lumen diameter consequently elevates the blood pressure within the arterioles.<ref>{{Cite journal |last1=Renna |first1=Nicolás F. |last2=de las Heras |first2=Natalia |last3=Miatello |first3=Roberto M. |date=2013-07-22 |title=Pathophysiology of Vascular Remodeling in Hypertension |journal=International Journal of Hypertension |language=en |volume=2013 |pages=e808353 |doi=10.1155/2013/808353 |pmid=23970958 |pmc=3736482 |issn=2090-0384 |doi-access=free }}</ref> Conversely, decreased sympathetic activity within the vasomotor nerves causes vasodilation of the vessels thereby decreasing blood pressure.<ref>{{Citation |last1=Schwarzwald |first1=Colin C. |title=Chapter 3 - The Cardiovascular System |date=2009-01-01 |url=https://www.sciencedirect.com/science/article/pii/B9781416023265000031 |work=Equine Anesthesia (Second Edition) |pages=37–100 |editor-last=Muir |editor-first=William W. |access-date=2023-11-17 |place=Saint Louis |publisher=W.B. Saunders |isbn=978-1-4160-2326-5 |last2=Bonagura |first2=John D. |last3=Muir |first3=William W. |editor2-last=Hubbell |editor2-first=John A. E.}}</ref>  

===Aorta===
{{main|Aorta}}
[[File:2121 Aorta.jpg|thumb|The [[aorta]] is the largest blood vessel in human body.]]
The [[aorta]] is the root [[systemic circulation|systemic]] artery (i.e., main artery). In humans, it receives blood directly from the left [[Ventricle (heart)|ventricle]] of the heart via the [[aortic valve]]. As the aorta branches and these arteries branch, in turn, they become successively smaller in diameter, down to the [[arteriole]]s. The [[arteriole]]s supply [[capillaries]], which in turn empty into [[venule]]s. The first branches off of the aorta are the [[Coronary circulation|coronary arteries]], which supply blood to the heart muscle itself. These are followed by the branches of the aortic arch, namely the [[brachiocephalic artery]], the [[left common carotid]], and the [[subclavian artery|left subclavian]] arteries.

=== Capillaries ===
{{main|Capillaries}}
The [[capillaries]] are the smallest of the blood vessels and are part of the [[microcirculation]]. The microvessels have a width of a single cell in diameter to aid in the fast and easy [[Diffusion#Diffusion vs. bulk flow|diffusion]] of gasses, sugars and nutrients to surrounding tissues. Capillaries have no [[smooth muscle]] surrounding them and have a diameter less than that of [[red blood cells]]; a red blood cell is typically 7 micrometers outside diameter, capillaries typically 5 micrometers inside diameter. The red blood cells must distort in order to pass through the capillaries.

These small diameters of the capillaries provide a relatively large surface area for the exchange of gasses and nutrients.

==Clinical significance==
[[File:Atherosclerosis diagram.png|thumbnail|right|Diagram showing the effects of [[atherosclerosis]] on an artery]]

[[Systemic circulation|Systemic]] arterial pressures are generated by the forceful contractions of the heart's [[left ventricle]]. High [[blood pressure]] is a factor in causing arterial damage. Healthy resting arterial pressures are relatively low, mean systemic pressures typically being under {{cvt|100|mmHg|psi kPa|lk=on}} above surrounding [[atmospheric pressure]] (about {{cvt|760|mmHg|psi kPa|disp=comma}} at sea level). To withstand and adapt to the pressures within, arteries are surrounded by varying thicknesses of [[smooth muscle]] which have extensive elastic and inelastic [[connective tissue]]s. The pulse pressure, being the difference between [[Systole (medicine)|systolic]] and [[Diastole|diastolic]] pressure, is determined primarily by the amount of blood ejected by each heart beat, [[stroke volume]], versus the volume and elasticity of the major arteries.

A [[blood squirt]], also known as an arterial gush, is the effect when an artery is [[cutting|cut]] due to the higher arterial pressures. Blood is spurted out at a rapid, intermittent rate, that coincides with the heartbeat. The amount of [[exsanguination|blood loss]] can be copious, can occur very rapidly, and be life-threatening.<ref>{{cite web|url=http://www.brooksidepress.org/Products/OperationalMedicine/DATA/operationalmed/Manuals/Standard1stAid/chapter3.html|title=U.S. Navy Standard First Aid Manual, Chapter 3 (online)|access-date=3 Feb 2003}}</ref>

Over time, factors such as elevated arterial [[blood sugar]] (particularly as seen in [[diabetes mellitus]]), [[lipoprotein]], [[cholesterol]], [[high blood pressure]], [[stress (psychological)|stress]] and [[Tobacco smoking|smoking]], are all implicated in damaging both the [[endothelium]] and walls of the arteries, resulting in [[atherosclerosis]]. Atherosclerosis is a disease marked by the hardening of arteries. This is caused by an [[atheroma]] or plaque in the artery wall and is a build-up of cell debris, that contain [[lipid]]s, (cholesterol and [[fatty acids]]), [[calcium]]<ref name=":0">Bertazzo, S. ''et al.'' Nano-analytical electron microscopy reveals fundamental insights into human cardiovascular tissue calcification. ''Nature Materials'' '''12''', 576-583 (2013).</ref><ref>Miller, J. D. Cardiovascular calcification: Orbicular origins. ''Nature Materials'' '''12''', 476-478 (2013).</ref> and a variable amount of [[fibrous connective tissue]].

Accidental intra-arterial injection either [[iatrogenic]]ally or through recreational drug use can cause symptoms such as intense pain, [[paresthesia]] and [[necrosis]]. It usually causes permanent damage to the limb;  often [[amputation]] is necessary.<ref>{{cite journal|last1=Sen MD|first1=Surjya|last2=Nunes Chini MD Phd|first2=Eduardo|last3=Brown MD|first3=Michael J.|title=Complications After Unintentional Intra-arterial Injection of Drugs: Risks, Outcomes, and Management Strategies|volume=80|issue=6|pages=783–95|url=http://www.mayoclinicproceedings.org/article/S0025-6196(11)61533-4/fulltext|journal=Mayo Clinic Proceedings|publisher=MAYO Clinic|access-date=25 August 2014|format=Online archive of Volume 80, Issue 6, Pages 783–795, June 2005 Mayo Clinic Proceedings|date=June 2005|quote=Unintentional intra-arterial injection of medication, either iatrogenic or self-administered, is a source of considerable morbidity. Normal vascular anatomical proximity, aberrant vasculature, procedurally difficult situations, and medical personnel error all contribute to unintentional cannulation of arteries in an attempt to achieve intravenous access. Delivery of certain medications via arterial access has led to clinically important sequelae, including paresthesias, severe pain, motor dysfunction, compartment syndrome, gangrene, and limb loss. We comprehensively review the current literature, highlighting available information on risk factors, symptoms, pathogenesis, sequelae, and management strategies for unintentional intra-arterial injection. We believe that all physicians and ancillary personnel who administer intravenous therapies should be aware of this serious problem.|pmid=15945530|doi=10.1016/S0025-6196(11)61533-4|doi-access=free}}</ref>

== History ==
{{Further|Circulatory system#History}}
Among the [[Ancient Greeks]] before [[Hippocrates]], all blood vessels were called Φλέβες, ''phlebes''. The word ''arteria'' then referred to the [[windpipe]].<ref>The heart and the vascular system in ancient Greek medicine. From Alcmaeon to Galen. Oxford University Press 1973, special edition for Sandpiper Books 2001. ISBN 0-19-858135-1 p.24</ref> [[Herophilos]] was the first to describe anatomical differences between the two types of blood vessel. While [[Empedocles]] believed that the blood moved to and fro through the blood vessels, there was no concept of the [[capillary]] vessels that join arteries and veins, and there was no notion of circulation.<ref>The heart and the vascular system in ancient Greek medicine. From Alcmaeon to Galen. Oxford University Press 1973, special edition for Sandpiper Books 2001. ISBN 0-19-858135-1 p.18</ref> [[Diogenes of Apollonia]] developed the theory of ''pneuma'', originally meaning just air but soon identified with the [[soul]] itself, and thought to co-exist with the blood in the blood vessels.<ref>The heart and the vascular system in ancient Greek medicine. From Alcmaeon to Galen. Oxford University Press 1973, special edition for Sandpiper Books 2001. ISBN 0-19-858135-1 p.26</ref> The arteries were thought to be responsible for the transport of air to the tissues and to be connected to the [[trachea]]. This was as a result of finding the arteries of cadavers devoid of blood. 

In medieval times, it was supposed that arteries carried a fluid, called "spiritual blood" or "vital spirits", considered to be different from the contents of the [[vein]]s. This theory went back to [[Galen]]. In the late medieval period, the [[Vertebrate trachea|trachea]],<ref>Oxford English Dictionary.</ref> and [[ligaments]] were also called "arteries".<ref>Shakespeare, William. Hamlet Complete, Authoritative Text with Biographical and Historical Contexts, Critical History, and Essays from Five Contemporary Critical Perspectives. Boston: Bedford Books of St. Martins Press, 1994. pg. 50.</ref>

[[William Harvey]] described and popularized the modern concept of the circulatory system and the roles of arteries and veins in the 17th century. 

[[Alexis Carrel]] at the beginning of the 20th century first described the technique for vascular suturing and anastomosis and successfully performed many [[organ transplantation]]s in animals; he thus actually opened the way to modern [[vascular surgery]] that was previously limited to vessels' permanent ligation.

==References==
{{Reflist|30em}}

==External links==
{{wiktionary}}
{{Commons category|Arteries}}
* [http://howmed.net/contents/anatomy/gross-anatomy/arterial-system/ Human arterial system]

{{Human systems and organs}}
{{Arteries and veins}}
{{Human arteries}}

{{Authority control}}

[[Category:Angiology]]
[[Category:Cardiovascular physiology]]
[[Category:Cardiovascular system]]