Function: collect blood from the microvascular bed and carry it away from tissues to heart.
Function: fluid exchange, white blood cells emigration from blood vessels to enter the tissues.
Composition: endothelial lining, pericytes are enclosed by a basement membrane.
Composition: 1 - 2 smooth muscle cells layers amid collagen fibers or not, ground substance.
Composition: thin sheath of connective tissue.
Function: cinvey blood against gravity.
Location: limbs, venae cavae, and the pulmonary veins.
Composition: endothelial lining with basement membrane sparse subendothelial layer of connective tissue, smooth muscle cells, thin internal elastic membrane.
Composition: smooth muscle cells amid collagen fibers, relatively little elastic material, ground substance, external elastic membrane material.
Composition: longitudinally oriented bundles of smooth muscle cells, collagen and elastic fibers, fibroblasts, macrophages and adipose cells, blood vessels (vasa vasorum), nerves (nervi vascularis).
Function: allow blood to flow only in one direction.
Composition: semilunar flaps consisting of a thin connective tissue covered with endothelial cells.
Location: cranial cavity, retina, placenta, and spleen.
Composition: endothelial lining with basement membrane and connective tissue.