Ductus arteriosus
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202063680
2008-03-30T15:18:08Z
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{{Infobox Artery |
Name = {{PAGENAME}} |
Latin = |
GraySubject = 139 |
GrayPage = 540 |
Image = Gray502.png |
Caption = Plan of the fetal circulation. ("Ductus arteriosus" visible at upper right.) |
Image2 = Patent ductus arteriosus.jpg |
Caption2 = Heart cross-section with PDA |
BranchFrom = [[pulmonary artery]] |
BranchTo = [[aortic arch]] |
Vein = [[ductus venosus]] |
Precursor = [[Aortic arches|aortic arch]] 6 |
Supplies = |
MeshName = Ductus+Arteriosus |
MeshNumber = A07.541.278.395 |
DorlandsPre = d_29 |
DorlandsSuf = 12314749 |
}}
In the developing [[fetus]], the '''ductus arteriosus''' ('''DA''') is a [[shunt (medical)|shunt]] connecting the [[pulmonary artery]] to the [[aorta|aortic arch]] that allows most of the [[blood]] from the [[right ventricle]] to bypass the fetus' fluid-filled [[lung]]s. During [[fetal development]], this shunt protects the lungs from being overworked and allows the right ventricle to strengthen. There are two other fetal shunts, the [[ductus venosus]] and the [[foramen ovale (heart)|foramen ovale]].
==Eponym==
The ductus arteriosus is sometimes called the '''ductus Botalli''', after [[Leonardo Botallo]], although the discovery should have been attributed to [[Giulio Cesare Aranzi]], to whom (less commonly) the [[ductus venosus]] is named.<ref>{{WhoNamedIt|doctor|264}}</ref>
==Closure at birth==
When the [[newborn]] takes its very first [[breath]], pulmonary [[vascular resistance]] falls due to physical opening of the [[pulmonary]] [[capillaries]] and [[attenuation]] of [[wiktionary:intrauterine|intrauterine]] [[hypoxia (medical)|hypoxic]] pulmonary [[vasoconstrictor|vasoconstriction]]. Decreased pulmonary vascular resistance increases pulmonary blood flow while pulmonary vascular [[blood pressure|pressure]] falls below aortic pressure. At the same time, the lungs release [[bradykinin]] (vasodilator) and falling [[prostaglandin]] levels cause [[wiktionary:constrict|constrict]]ion of the [[smooth muscle]] in wall of the DA, reducing flow. Bradykinin works by acting on eNOS to increase NO produced, thus inducing vasodilatation. ACE breaks down bradykinin and therefore, ACE inhibitors aid in prolonging the action of vasodilatation by bradykinin. Additionally, because of reduced pulmonary resistance, more blood flows from the pulmonary arteries to the lungs and thus the lungs deliver more [[oxygen]]ated blood to the left heart. This further increases aortic pressure so that flow in DA may [[transient]]ly reverse.
Usually, the DA begins to close when breathing is established, and is completely sealed after four to ten days. A cord-like [[wiktionary:vestige|vestige]] of the DA, called the [[ligamentum arteriosum]], remains to connect the exterior of the [[left pulmonary artery]] to the exterior of the aortic arch.
Certain medications given to the mother during the pregnancy may decrease the size or completely close the DA prior to birth.{{Fact|date=March 2008}}
When the [[ligamentum arteriosum]] forms it traps the left branch of the recurrent left vagus nerve in the thorax.
==Patent ductus arteriosus==
{{Main|Patent ductus arteriosus}}
Failure of a child's DA to close after birth results in a condition called [[patent ductus arteriosus]] and the generation of a [[left-to-right shunt]]. If left uncorrected, patency leads to [[pulmonary hypertension]] and possibly [[congestive heart failure]] and [[cardiac arrhythmia]]s. Closure may be induced with a drug class known as [[NSAIDs]] such as [[indomethacin]] or [[ibuprofen]] because these drugs inhibit prostaglandin synthesis. [[Prostaglandins]] are responsible for maintaining the ductus arteriosus.
==References==
<references/>
==External links==
* [http://mcb.berkeley.edu/courses/mcb135e/fetal.html Circulatory changes at birth] at berkeley.edu
{{Development of circulatory system}}
[[Category:Embryology]]
[[de:Ductus arteriosus]]
[[fr:Canal artériel]]
[[it:Dotto arterioso di Botallo]]
[[ja:動脈管開存症]]
[[no:Ductus arteriosus]]
[[nn:Ductus arteriosus]]
[[pt:Ductus arteriosus]]
[[sr:Дуктус артериозус (Ботали)]]
[[uk:Відкрита артеріальна протока]]