lymphatic system. functions of the lymphatic system fluid balance - returns interstitial fluid to...

Lymphatic System

Functions of the Lymphatic System

• Fluid Balance - returns interstitial fluid to the blood

• Fat [and fat soluble vitamins] Absorption - from the digestive tract via lacteals into the venous circulation

• Immunity - using lymphocytes & phagocytes microorganisms are filtered and removed from circulation

Components• Lymph - fluid similar to plasma

• Lymphatic Vessels - begin with blind-ended sacs at capillaries, and merge to form lymphatic vessels - similar to veins in structure. Vessels merge and drain into ‘trunks’ which dump lymph into ducts– right lymphatic duct– thoracic duct

Lymphatic Organs

• Lymph Nodes - round, oval or bean shaped, less than 2.5 cm in length. Distributed throughout body, except for CNS & bone marrow.

Lymphatic Organs

• Tonsils - 3 groups: pharyngeal [adenoids], palatine, lingual

• Spleen - filters blood, not lymph

• Thymus

• Appendix

Human T-Lymphocyte

Immunity [Latin: immunis = exempt]

2 main functions: recognition & response

can be innate - born with - will not be specific

or acquired / adaptive - will be specific, due to memory [long or short term memory]

Innate - 4 types of defensive barriers: anatomic, physiologic, phagocytic, inflammatory