Lymphatic System Introduction Consists of lymph lymph vessels

Lymphatic System

Introduction • Consists of : lymph, lymph vessels, lymph nodes, and lymph tissue

Lymph • Thin watery fluid • Made of interstitial, or intercellular fluid that forms when plasma diffuses into tissue spaces. • Composed of water, digested nutrients, salts, hormones, CO 2, lymphocytes, and metabolic waste

Lymphatic Vessels • Located throughout the body • Lymphatic capillaries: small saclike open-ended vessels; acts like drainpipes; picks up lymph at tissues throughout the body; capillaries joint together to form larger lymphatic vessels • Lymphatic vessels carry lymph • Skeletal muscle contraction causes lymph flow

Lymphatic Vessels cont’ • Vessels pass through lymph nodes • Contain valves that keep lymph flowing in one direction • Specialized lymphatic capillaries (lacteals) are located in the small intestine • Pick up digested fats or lipids • Lymph is mixed with lipids = chyle • Lacteals transport chyle to the bloodstream

Lymph Nodes • Popularly called “glands” • Located all over the body, usually in small clusters • Small round masses ranging in size from a pinhead to an almond • Lymph vessels bring lymph to the nodes

Lymph Nodes • Nodes filter out impurities such as: • Carbon • Cancer cells • Pathogens • Dead blood cells • Lymphatic tissue in nodes also produce lymphocytes: (a type of leukocyte= WBC), and antibodies (substances that fight infection)

Lymph Nodes • Purified lymph, with lymphocytes and antibodies added leaves the lymph node by a single lymphatic vessel

Lymphatic Ducts • As lymphatic vessels leave the lymph nodes, they continue to join together to form larger lymph vessels • Eventually they drain into one of two lymphatic ducts: Right or the Thoracic

Lymphatic Ducts • Right Duct: • Short tube • Receives all the purified lymph form the right side of the neck and head, the right chest, and the right arm

Lymphatic Ducts Thoracic Duct: Much larger tube Drains lymph from the rest of the body Empties into the R Subclavian Vein, returning purified lymph to the blood

Lymphatic Ducts • Thoracic Duct cont’ • Enlarged pouchlike structure called the cisterna chyli is located at the start of the thoracic duct and serves as storage area for purified lymph

Lymph Tissue • Located throughout the body in addition to being in lymph nodes • Tonsils, spleen, and thymus are examples of lymphatic tissue • Tonsils: Masses of lymph tissue; filter interstitial fluid; 3 pairs of tonsils= palantine, pharngeal (adenoids), and lingual

Lymph Tissue • Spleen • Organ located on L side in back of the upper part of the stomach • Produces leukocytes and antibodies • Destroys old RBC’s; Stores RBC’s • Destroys thrombocytes, • Filters some metabolites and wastes from tissue

Lymph Tissue • Thymus • Mass of lymph tissue located in the center of the upper chest • Atrophies or wastes away after puberty and is replaced by fat and connective tissue

Lymph Tissue • Functions during early life by producing antibodies and manufacturing lymphocytes to fight infection • Function is taken over by lymph nodes after it atrophies