Describe the structure and function of lymph capillaries, noting the complimentary relationship they share with blood capillaries.
Like blood capillaries, the lymph capillaries are composed of a single layer of endothelium and are distributed throughout all body tissues. The lymph capillaries function to re absorb the small amount of water that moves from blood to tissue in the capillary beds but that fails to be reabsorbed by the blood capillaries. Unlike blood capillaries, the walls of lymph capillaries are highly permeable to blood proteins and collect any that may have leaked out of the blood capillaries despite their impermeability to blood proteins. The reabsorption of blood proteins by the lymph capillaries is essential in maintaining the proper osmotic balance between the tissue fluid and blood. If lymph vessels are blocked, proteins build up in the tissue fluid, the osmotic difference between the tissue fluid and blood decreases, the blood cannot re absorb the water it releases into the tissue, and the tissues become swollen, a condition called edema. Further, it is the lymph capillaries rather than the blood capillaries that absorb most of the fats digested in the intestine.
