View source for Biology:Coronary arteries

{{Short description|Artery of the coronary circulation which transports blood into and out of the cardiac muscle}}
{{Infobox artery
| Name = Coronary arteries
| Image = Coronary arteries.svg
| Caption = Coronary arteries (labeled in red text) and other major landmarks (in blue text)
}}

The '''coronary arteries''' are the arterial blood vessels of [[Medicine:Coronary circulation|coronary circulation]], which transport oxygenated blood to the [[Biology:Cardiac muscle|heart muscle]]. The [[Biology:Heart|heart]] requires a continuous supply of oxygen to function and survive, much like any other tissue or organ of the body.<ref>{{Cite web|url=https://www.texasheart.org/heart-health/heart-information-center/topics/the-coronary-arteries/|title=Coronary Arteries|website=Texas Heart Institute|language=en-US|access-date=2019-09-01}}</ref>

The coronary arteries wrap around the entire heart. The two main branches are the left coronary artery and right coronary artery. The arteries can additionally be categorized based on the area of the heart for which they provide circulation. These categories are called ''epicardial'' (above the epicardium, or the outermost tissue of the heart) and ''microvascular'' (close to the endocardium, or the innermost tissue of the heart).<ref>{{Cite journal|last1=Petersen|first1=J. W.|last2=Pepine|first2=C. J.|year=2014|title=Microvascular Coronary Dysfunction and Ischemic Heart Disease – Where Are We in 2014?|journal=Trends in Cardiovascular Medicine|volume=25|issue=2|pages=98–103|doi=10.1016/j.tcm.2014.09.013|pmc=4336803|pmid=25454903}}</ref>

Reduced function of the coronary arteries can lead to decreased flow of oxygen and nutrients to the heart. Not only does this affect supply to the heart muscle itself, but it also can affect the ability of the heart to pump blood throughout the body. Therefore, any disorder or disease of the coronary arteries can have a serious impact on health, possibly leading to [[Medicine:Angina|angina]], a heart attack, and even death.<ref>{{Cite web|url=https://www.hopkinsmedicine.org/health/conditions-and-diseases/anatomy-and-function-of-the-coronary-arteries|title=Anatomy and Function of the Coronary Arteries|website=www.hopkinsmedicine.org|language=en|access-date=2019-09-01}}</ref>

== Structure ==
The coronary arteries are mainly composed of the left and right coronary arteries, both of which give off several branches, as shown in the 'coronary artery flow' figure.

* [[File:Coronary arteries flow.png|thumb|Coronary artery flow|384x384px]]Aorta
**Left coronary artery
***Left anterior descending artery
***Left circumflex artery
***Posterior descending artery
***Ramus or intermediate artery
**Right coronary artery
***Right marginal artery
***Posterior descending artery

The left coronary artery arises from the aorta within the left cusp of the aortic valve and feeds blood to the left side of the [[Biology:Heart|heart]]. It branches into two arteries, the left anterior descending and the left circumflex. The left anterior descending artery perfuses the interventricular septum and anterior wall of the [[Medicine:Ventricle (heart)|left ventricle]]. The left circumflex artery perfuses the left ventricular free wall. In approximately 33% of individuals, the left coronary artery gives rise to the posterior descending artery<ref name=":0">{{Cite book|title=Physiology|last=Costanzo|first=Linda S.|isbn=9780323511896|edition=6th|date=2018|publisher=[[Company:Elsevier|Elsevier]]|location=Philadelphia, PA|oclc=965761862}}</ref> which perfuses the posterior and inferior walls of the left ventricle. Sometimes a third branch is formed at the fork between left anterior descending and left circumflex arteries, known as a ''ramus'' or ''intermediate artery''.<ref name="Hurst">{{cite book|title=Hurst's The Heart|last=Fuster|first=V|author2=Alexander RW|author3=O'Rourke RA|publisher=McGraw-Hill|year=2001|isbn=978-0-07-135694-7|edition=10th|page=53}}</ref>

The right coronary artery (RCA) originates within the right cusp of the aortic valve. It travels down the right coronary sulcus, towards the crux of the heart. The RCA primarily branches into the right marginal arteries, and, in 67% of individuals, gives place to the posterior descending artery.<ref name=":0" /> The right marginal arteries perfuse the right ventricle and the posterior descending artery perfuses the left ventricular posterior and inferior walls.

There is also the '''conus artery''', which is only present in about 45 percent of the human population, and which provides collateral blood flow to the heart when the left anterior descending artery is occluded.<ref>{{cite journal|vauthors=Wynn GJ, Noronha B, Burgess MI|year=2008|title=Functional significance of the conus artery as a collateral to an occluded left anterior descending artery demonstrated by stress echocardiography|journal=International Journal of Cardiology|volume=140|issue=1|pages=e14–e15|doi=10.1016/j.ijcard.2008.11.039|pmid=19108914}}</ref><ref>{{cite journal|vauthors=Schlesinger MJ, Zoll PM, Wessler S|year=1949|title=The conus artery: a third coronary artery|journal=American Heart Journal|volume=38|issue=6|pages=823–838|doi=10.1016/0002-8703(49)90884-4|pmid=15395916}}</ref>

==Clinical significance==
{{Main|Medicine:Coronary artery disease}}
[[File:Atherosclerosis 2011.jpg|thumb|Atherosclerosis]]
Narrowing of the arteries can be caused by a process known as [[Medicine:Atherosclerosis|atherosclerosis]] (most common), [[Medicine:Arteriosclerosis|arteriosclerosis]], or [[Medicine:Arteriolosclerosis|arteriolosclerosis]]. This occurs when [[Medicine:Atheroma|plaques]] (made up of deposits of [[Chemistry:Cholesterol|cholesterol]] and other substances) build up over time in the walls of the arteries. [[Medicine:Coronary artery disease|Coronary artery disease]] (CAD) or ischemic heart disease are the terms used to describe narrowing of the coronary arteries.<ref>{{Cite web|url=https://www.cdc.gov/heartdisease/coronary_ad.htm|title=Coronary Artery Disease: Causes, Diagonosis & Prevention{{!}} cdc.gov|date=2018-10-09|website=www.cdc.gov|language=en-us|access-date=2019-09-01}}</ref>

As the disease progresses, plaque buildup can partially block blood flow to the heart muscle. Without enough blood supply ([[Medicine:Ischemia|ischemia]]), the heart is unable to work properly, especially under increased stress. [[Medicine:Angina|Stable angina]] is chest pain on exertion that improves with rest. Unstable angina is chest pain that can occur at rest, feels more severe, and/or last longer than stable angina. It is caused by more severe narrowing of the arteries.<ref>{{Cite web|url=https://my.clevelandclinic.org/health/diseases/16898-coronary-artery-disease|title=Coronary Artery Disease|website=Cleveland Clinic|language=en|access-date=2019-09-01}}</ref>

[[File:Heart attack-NIH.gif|thumb|Heart attack]]
A heart attack results from a sudden plaque rupture and formation of a [[Medicine:Thrombus|thrombus]] (blood clot) that completely blocks blood flow to a portion of the heart, leading to tissue death (infarct).

CAD can also result in [[Medicine:Heart failure|heart failure]] or [[Medicine:Heart arrhythmia|arrhythmias]]. Heart failure is caused by chronic oxygen deprivation due to reduced blood flow, which weakens the heart over time. Arrhythmias are caused by inadequate blood supply to the heart that interferes with the heart's electric impulse.

The coronary arteries can constrict as a response to various stimuli, mostly chemical. This is known as a [[Medicine:Coronary reflex|coronary reflex]].

There is also a rare condition known as [[Medicine:Spontaneous coronary artery dissection|spontaneous coronary artery dissection]], in which the wall of one of the coronary arteries tears, causing severe pain.<ref>{{cite journal |last1=Franke |first1=Kyle B |last2=Wong |first2=Dennis TL |last3=Baumann |first3=Angus |last4=Nicholls |first4=Stephen J |last5=Gulati |first5=Rajiv |last6=Psaltis |first6=Peter J |title=Current State-of-play in Spontaneous Coronary Artery Dissection |journal=Cardiovascular Diagnosis and Therapy |date=April 4, 2019 |volume=9 |issue=3 |pages=281–298 |doi=10.21037/cdt.2019.04.03 |pmid=31275818 |url=http://cdt.amegroups.com/article/view/25190/23518|pmc=6603494 |doi-access=free }}</ref> Unlike CAD, spontaneous coronary artery dissection is not due to plaque buildup in arteries, and tends to occur in younger individuals, including women who have recently given birth or men who do intense exercise.<ref>{{Cite web|url=https://www.heart.org/en/health-topics/heart-attack/about-heart-attacks/coronary-artery-dissection-not-just-a-heart-attack|title=Coronary Artery Dissection: Not Just a Heart Attack|website=www.heart.org|language=en|access-date=2019-09-02}}</ref>

Coronary artery dominance is described as the coronary artery that give branches to supply the right posterior descending artery and supplies the inferior wall of the heart. In 80 to 85% of the population, the right coronary artery supplies the posterior descending artery, making it right heart dominant while in 7 to 13% of the population, the left coronary artery supplies the posterior descending artery, making it left heart dominant. In 7 to 8% of the population, both right and left coronary arteries supplies the posterior descending artery, making it right and left co-dominance. Narrowing of coronary arteries is more frequent in those who are left dominant when compared to those who have right dominant or co-dominant hearts.<ref name="pmid35099044">{{cite journal |vauthors=Aricatt DP, Prabhu A, Avadhani R, Subramanyam K, Manzil AS, Ezhilan J, Das R |title=A study of coronary dominance and its clinical significance |journal=Folia Morphologica |volume= 82|issue= 1|pages= 102–107|date=January 2022 |pmid=35099044 |doi=10.5603/FM.a2022.0005 |s2cid=246428206 |url=|doi-access=free }}</ref>

==Name etymology==
 {{multiple image
 | width = 80
 | footer = 
 | image1 = Busto di sol, età giulio-claudia.JPG
 | caption1 = Radiant crown
 | image2 = Heart with ventricles and arteries.jpg
 | caption2 = Model of human heart
 }}

The word ''{{Lang|la|corona}}'' is a [[Social:Latin language|Latin]] word meaning "crown", from the [[Social:Ancient Greek|Ancient Greek]] {{Lang|grc|κορώνη|italic=no}} ({{Lang|grc-latn|korōnè}}, “garland, wreath”). It was applied to the coronary arteries because of a notional resemblance (compare the photos).

The word ''arterie'' in Anglo-French (''{{Lang|ang|artaire}}'' in [[Social:Old French|Old French]], and ''{{Lang|la|artērium}}'' in Latin) means "windpipe" and "an artery." It was applied to the coronary arteries because the arteries do not contain blood after death. 
{{Clear}}

== See also ==

* [[Medicine:Coronary circulation|Coronary circulation]]
* Left coronary artery
* Right coronary artery
* [[Biology:Heart|Heart]]
* [[Medicine:Cardiology|Cardiology]]
* [[Medicine:Coronary artery disease|Coronary artery disease]]
* [[Medicine:Angina|Angina]]
* Unstable angina
* Heart attack
* Cardiac skeleton
* Coronary sinus
* [[Medicine:Foramen ovale (heart)|Foramen ovale (heart)]]
* Patent foramen ovale

==Additional images==
[[File:Blausen 0260 CoronaryVessels Anterior.png|none|thumb]]
[[File:Blausen 0261 CoronaryVessels Posterior.png|none|thumb]]

==References==

{{Reflist}}


[[Category:Anatomy]]

{{Sourceattribution|Coronary arteries}}