Suprachoroid lamina which the vessels and nerves are transmitted. Suprachoroid lamina The choroid consists mainly of a dense capillary plexus, and of small arteries and veins carrying blood to and returning it from this plexus. On its external surface is a thin membrane, the suprachoroid lamina, composed of delicate non-vascular lamellae—each lamella consisting of a network of fine elastic fibers among which are branched pigment cells. During embryological development, it is derived from the neural crest. The spaces between the lamellæ are lined by endothelium, and open freely into the perichoroidal lymph space, which, in its turn, communicates with the periscleral space
Great arteries birth. Great arteries The great arteries are the primary arteries that carry blood away from the heart, which include: The great arteries originate from the aortic arches during embryonic development. The aortic arches start as five pairs of symmetrical vessels connecting the heart with the dorsal aorta but then undergo a significant remodelling, in which some of these vessels regress (aortic arches 1 and 2), the 3rd pair of arches contribute to form the common carotids, the right 4th will contribute to the base and central part of the right subclavian artery, while the left 4th will form the central