LYMPHATIC SYSTEM STRUCTURE LYMPH Strawcolored similar to plasma

LYMPHATIC SYSTEM STRUCTURE

LYMPH �Straw-colored, similar to plasma �Diffuses from the capillaries into the tissue spaces �Interstitial fluid (tissue fluid)– in spaces b/t cells �Composed of water, lymphocytes, oxygen, digested nutrients, hormones, salts, carbon dioxide, and urea �No red cells or proteins (too large to diffuse)

LYMPH VESSELS �Closely parallel veins �Form an extensive and branchlike system throughout the body �Located in almost all tissues and organs that have blood vessels Not in cuticles, nails, hair, cartilage, CNS, red marrow, epidermis, eyeballs, inner ear, or spleen �Thoracic duct – largest lymph vessel �Responsible for spreading cancer cells �SEE FIGURE 15 -1 pg 311 and FIGURE 15 -2 pg 312

LYMPH NODES �Tiny, oval shaped, size of pinhead to size of almond �Each covered by a capsule of fibrous connective tissue that extends into the node �Located alone or grouped in various places along the lymph vessels �Consists of different kinds of lymphocytes Lymph sinuses (spaces b/t lymph tissue) contain macrophages �Microorganisms or foreign substances stimulate the production of lymphocytes (immune response)

TONSILS �Masses of lymphatic tissue which are capable of producing lymphocytes and filtering bacteria �Play an important role in the line of defense against infection �Get smaller as person gets older �Located in throat �Adenoids – tonsils on upper part of throat �Tonsillitis Inflamed, infected tonsils

SPLEEN �Sac-like mass of lymphatic tissue �Located near upper left abdominal cavity, just below diaphragm �Forms lymphocytes and monocytes �Filters blood and stores large amounts of RBCs �Destroys and removes old or fragile RBCs

THYMUS GLAND �Located in the upper anterior part of the chest, above the heart �Consists largely of lymphatic tissue �Produces lymphocytes (T-lymphocytes)