<prompt> The anterior and posterior neuropores close during which week of embryonic development?Week 2Week 3Week 4Week 5  <response>: Anterior and posterior neuropores close during week 4 of development- the anterior neuropore by day 25, the posterior neuropore by day 28. Failure of the fusion of anterior neuropore results in Anencephaly Failure of the fusion of posterior neuropore results in Rachis chisis. Ref: Grays Anatomy 41st edition Pgno: 238 