Review: Introduction to the Lymphatic System

Here is what we have learned from Introduction to the Lymphatic System:

• The lymphatic system returns excess interstitial fluid to the blood, absorbs fats and fat-soluble vitamins, and provides defense against disease.
• Lymph is the fluid in the lymphatic vessels. It is picked up from the interstitial fluid and returned to the blood plasma.
• Lymphatic vessels carry fluid away from the tissues.
• The right lymphatic duct drains lymph from the upper right quadrant of the body and the thoracic duct drains all the rest.
• Pressure gradients that move fluid through the lymphatic vessels come from the skeletal muscle action, respiratory movements, and contraction of smooth muscle in vessel walls.
• Lymph enters a lymph node through afferent vessels, filters through the sinuses, and leaves through efferent vessels.
• Tonsils are clusters of lymphatic tissue associated with openings into the pharynx and provide protection against pathogens that may enter through the nose and mouth.
• The spleen is a lymph organ that filters blood and also acts as a reservoir for blood.
• The thymus is large in the infant and atrophies after puberty.