Ch27: The Lymphatic System Flashcards
Name the types of transport sytstems in the body
-Primary: blood circulatory system
-Secondary: Lymphatic (one way system of dead ending vessels and lymph nodes)
Describe the formation of lymph/tissue fluid/
-Consists of fluid and proteins that are forced out of the capillaries due to high pressure in the arteries
-Similar to plasma (no RBC platelets or larger proteins)
-milky appearance due to high fat concentration
Explain the drainage of lymph
-Lymph is drained to prevent swelling (oedema) in tissues
-90% re-enters the capillaries by osmosis
-10% enters dead-ending tubes called lymph vessels, which eventually empty into the blood stream
Describe lymph vessels
-Lymph is moved slowly through lymph vessels by the muscular walls of vessels and by general body movements pressing on the vessels
-Valves ensure that lymph moves in one direction towards the shoulders
-Lymph is returned to the blood stream at the subclavian veins near the collar bones
What is a lymph node
Small swellings found along the lymph vessels
Describe structure of lymph nodes
-Contain large numbers of WBC and have channels through which lymph flows
-Occur in clusters that form glands
-Found in neck, tonsils, armpits, thymus, groin
How do lymph nodes fight infection?
-Filtering bacteria from lymph as it passes through
-Maturing and storing large numbers of white blood (lymphocytes) cells that kill micro-organisms or produce antibodies
What are the functions of the lymphatic system?
-To collect tissue fluid and return in to the blood
-To defend the body against infection by (functions of lymphnodes)
-To absorb and transport fats in the igestive system
What is the functions of lymph
-Surrounds all body cells and acts as a transport medium (materials that enter or exit cells pass through)
-Found in lacteals in the villi and involved in absorbtion of fats
