Ductus arteriosis

Ductus arteriosus
Plan of the fetal circulation. ("Ductus arteriosus" visible at upper right.)
Heart cross-section with PDA
Details
Precursor	aortic arch 6
Source	pulmonary artery
Branches	descending aorta
Vein	ductus venosus
Identifiers
Latin	Ductus arteriosus
MeSH	A07.541.278.395
Dorlands /Elsevier	d_29/12314749
TE	E5.11.2.1.2.0.17
FMA	79871
Anatomical terminology []

In the developing fetus, the ductus arteriosus, also called the ductus Botalli, is a blood vessel connecting the pulmonary artery to the proximal descending aorta. It allows most of the blood from the right ventricle to bypass the fetus's fluid-filled non-functioning lungs. Upon closure at birth, it becomes the ligamentum arteriosum. There are two other fetal shunts, the ductus venosus and the foramen ovale.

The ductus arteriosus is formed from the left 6th aortic arch during embryonic development and attaches to the final part of the aortic arch (the isthmus of aorta) and the first part of the pulmonary artery

Failure of the 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 arrhythmias.

The E series of prostaglandins are responsible for maintaining the patency of the DA (by dilation of vascular smooth muscle) throughout the fetal period. Prostaglandin E2 (PGE₂), produced by both the placenta and the DA itself, is the most potent of the E prostaglandins, but prostaglandin E1 (PGE₁) also has a role in keeping the DA open. PGE₁ and PGE₂ keep the DA open via involvement of specific PGE-sensitive receptors (such as EP4 and EP2). EP4 is the major receptor associated with PGE₂-induced dilation of the DA and can be found across the DA in smooth muscle cells. Immediately after birth, the levels of both PGE₂ and the EP4 receptors reduce significantly, allowing for closure of the DA and establishment of normal postnatal circulation.