The Lymphatic System & Immunity

Functions: Lymph – Fluid that goes between capillary blood and tissues. Lymph Vessels – transport excess tissue fluid back into circulatory system. Lymph Nodes – Produce lymphocytes, filter out harmful bacteria Spleen – produces lymphocytes and monocytes, blood reservoir, recycles old red blood cells. Thymus Gland – produces T-Lymphocytes

Lymph – straw colored fluid similar to plasma Composed of: Water Lymphocytes Some granulocytes Oxygen Digested nutrients Hormones Salts Carbon Dioxide Urea NO red blood cells or protein molecules

Functions of Lymph Carries digested food, Oxygen and hormones to cells. Carries waste back to capillaries for excretion. Propelled via skeletal muscle action (contraction & relaxation) one way, unlike blood, which is pumped via the heart

Lymph Vessels Pathway: Lymph from the left side of chest, the head and neck, abdominal area and lower limbs flow into the THORACIC DUCT. Thoracic Duct to the left subclavian vein Left subclavian vein to the superior vena cava Superior Vena Cava to the heart

Enlarged cervical lymph node Lymph Nodes Tiny, oval shaped structures the size of a pinhead to the size of an almond Located alone or grouped Site for lymph production Filter for screening out harmful substances If substance cannot be destroyed, the node becomes inflamed! Enlarged cervical lymph node

Tonsils and Adenoids Masses of lymphatic tissue that produce lymphocytes. Filter bacteria Get smaller with age Adenoids Tonsils

Spleen Sac-like mass of lymphatic tissue Located in upper left abdominal cavity, immediately inferior to the diaphragm Functions: Forms lymphocytes and monocytes Filters blood Stores large amounts of RBCs Destroys or removes old or fragile RBCs

Thymus Gland Located in the upper, anterior thorax, above the heart Also considered an endocrine gland Shrinks as you get older