<prompt> Berry aneurysm - defect lies in -Degeneration of internal elastic laminaDegeneration of mediamuscle cell layerDeposition of mucoid material in mediaLow grade inflammation of vessel wall  <response>: Berrys aneurysm is a brain aneurysm caused due to a defect in media. Berry aneurysms arise at the point of weakness in the arterial media, especially branch points in the circle of Willis.There is a congenital defect in tunica media of cerebral vessels which leads to aneurysm formation. 