Lymphatic vessels

Function: convey fluids from the tissues to the bloodstream.

Lymphatic capillaries

Function: remove protein-rich fluid from the intercellular spaces, integral component of the immune system

Composition: "blind-ending" tubes of endothelium with anchoring filaments between the incomplete basal lamina and the perivascular collagen.

Lymphatic ducts

Location: thoracic duct, right lymphatic duct.

Composition: endothelial lining with incomplete basement membrane, sparse subendothelial layer of connective tissue, elastic fibers.

Composition: smooth muscle cells amid collagen fibers, relatively little elastic material, ground substance.

Composition: longitudinally oriented bundles of smooth muscle cells, collagen and elastic fibers.

Valves

Function: prevent backflow of the lymph.

Composition: thin connective tissue covered with endothelial cells.