Lymphatic Vessels

Lymphatic Vessels - Lymphatic Vessels

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Lymphatic Vessels Lymphatic vessels occur throughout the body alongside arteries (in the viscera) or veins (in the  subcutaneous tissue). They are absent from the central nervous system, bone marrow, teeth, and  avascular tissues. Lymph capillaries, the smallest lymphatic vessels, begin as dead-end vessels. They  resemble blood capillaries, but are much more porous to surrounding fluids due to the  following two features: Valvelike openings form at the juncture of adjacent endothelial cells. Unlike  the tightly joined endothelial cells that make up the walls of blood capillaries, those of  lymph capillaries loosely overlap. When fluid pressure increases in surrounding  regions, the overlapped cells separate, allowing fluids to enter the lymph capillary.  When pressure inside the capillary exceeds the pressure outside, the spaces  between the endothelial cells close, holding fluids inside the capillary. Anchoring filaments attach the endothelial cells of the lymphatic vessels to 
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This note was uploaded on 11/10/2011 for the course PT 101 taught by Professor Staff during the Spring '10 term at Texas State.

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