1. Lymphatic System

2. Function and Structures of the Lymph System Two functions of the lymphatic system: 1. Absorb fats and vitamins from digestive system 2. Return waste products and extra fluid to circulatory system Structures of the lymphatic system: 1. Lymph fluid, lymph vessels, lymphatic capillaries, lacteals, lymph nodes, right lymphatic duct, thoracic duct, cisterna chyli, tonsils, spleen, thymus,

3. Structures of the Lymphatic System Lymph fluid – thin watery fluid which forms when plasma diffuses into tissue space Lymph vessels – located throughout the body in almost all of the tissues that have blood vessels have valves, always flow toward the thoracic (chest) cavity Lymphatic capillaries – small, open-ended lymph vessels that act like drainpipes These pick up lymph at tissues throughout the body One-way valves Lacteals – specialized lymphatic capillaries located in the small intestine and pick up lipids or fats

4. Structures of the Lymphatic System Lymph nodes – located all over the body usually in groups or clusters Location of lymphocyte production Nodes filter lymph fluid of harmful substances Also produce lymphocytes (WBC) and antibiotics Swollen lymph nodes may mean there is a disease process Right lymphatic duct – Short tube that receives all of the purified lymph from the right side of the head and neck, right chest, and right arm Empties into the right subclavian vein, returning the purified blood back to the system Thoracic duct – much larger tube Drains the lymph from the rest of the body Empties into the left subclavian vein

5. Structures of the Lymphatic System Cisterna chyli – an enlarged pouch-like structure located at the start of the thoracic duct Serves as a storage area for purified lymph before it returns to the blood stream

6. Structures of the Lymphatic System Other lymphatic tissues: Tonsils – masses of lymphatic tissue located in back of mouth on sides of throat Spleen – located beneath the left side of the diaphragm filters blood makes lymphocytes & monocytes removes old RBC’s Thymus – located above the heart behind the sternum important in immune and endocrine systems

7. Pathology of the Lymphatic System Adenitis (aden/o + it is) or Lymphadenitis - (lymphaden/o + -itis) inflammation of lymph nodes Lymphadenopathy – (lymphaden/o + -pathy) disease of lymph node Lymphedema – (lymph/o + -edema) swelling from lymph fluid accumulation Splenomegaly – (splen/o + -megaly) enlargement of the spleen www.hoslink.com/haematology/splenomegaly.jpg

8. Pathology of the Lymphatic System Hodgkin’s Lymphoma Chronic, malignant disease of the lymph nodes Most common form of lymphoma Lymphangitis Inflammation of lymphatic vessels Characteristic red streaks Tonsilitis Inflammation or infection of the tonsils Most cases are viral