True statement about Ductus Aeriosus is -

Ans. is 'd' i.e., May cause machinery murmur by its patency This question deals with the changes in blood circulation that occur at bih : o Closure of Ductus aeriosus The closure occurs almost immediately after bih by contraction of its muscular wall, mediated by bradykinin. i.e. Physiological closure. Anatomic closure occurs by proliferation of intima, and may take from 10-21 days (& not in 24 hrs. as given in choice 'A'). After obliteration, it forms ligamentum aeriosum. (& not the ligamentum venosum as given in choice 'b') Ligamentum venosum, on the other hand, is formed by closure of the ductus venosus. o "In neonates with congenital hea defects, till surgery is undeaken, PGE, (Alprostadil) is used to maintain patency of ductus aeriosus". Therefore prostaglandins maintain patency of ductus aeriosus, and not induce it to close (as given in choice 'C'). Prostaglandins maintains patency of ductus aeriosus NSAIDs - help in early closure of ducts aeriosus o "Shunt murmur is a continuous machinery murmur". The murmur is best heard at the 2nd left intercostal space and is also well heard below the left clavicle, where it maintains its continuous machinery character.