when is the ductus arteriosis normally renamed the ligamentum arteriosum
Ductus arteriosus In the developing fetus, the ductus arteriosus, also called the ductus Botalli, is a blood vessel connecting the main 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.
Connective tissue Connective tissue has a wide variety of functions that depend on the types of cells and the different classes of fibers involved. Loose and dense irregular connective tissue, formed mainly by fibroblasts and collagen fibers, have an important role in providing a medium for oxygen and nutrients to diffuse from capillaries to cells, and carbon dioxide and waste substances to diffuse from cells back into circulation. They also allow organs to resist stretching and tearing forces. Dense regular connective tissue, which forms organized structures, is a major functional component of tendons, ligaments and aponeuroses, and is also found in highly specialized organs such as the cornea.[12]:161 Elastic fibers, made from elastin and fibrillin, also provide resistance to stretch forces.[12]:171 They are found in the walls of large blood vessels and in certain ligaments, particularly in the ligamenta flava.[12]:173