You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is True statement about ductus arteriosus is: and explain in detail?
d. May cause a machinery murmur by its patency.(Ref: Nelson's 20/e p 497, Ghai 8/e p 413)Closure of ductus arteriosusPhysiological closure: occurs almost immediately after birth by contraction of muscular wall, mediated by bradykininAnatomic closure: occurs by proliferation of intima in 10-21 days; After obliteration, it forms ligamentum arteriosum. Note: Murmur due to PDA is classically referred to as a continuous machinery murmur.