The Lymphatic System

Components Lymphatic vessels Lymphoid organs  lymph nodes (connect incoming & outgoing lymph vessels)  spleen  thymus gland  red bone marrow

Lymphoid organs (a closer look)

Functions Collects tissue fluid (lymph) Absorbs fatty acids & glycerol Defence against disease  lymph nodes contain macrophages (destroy bacteria & infectious material)

Lymphatic Vessels Structurally like veins Have valves Movement of fluid (lymph) similar to movement in veins

Flow of Lymph Fluid RIGHT UPPER BODY Tissue fluid  Lymphatic capillaries  Lymphatic vessels  Right lymphatic duct  Right subclavian vein  SUPERIOR VENA CAVA LOWER BODY & UPPER LEFT Tissue fluid  Lymphatic capillaries  Lymphatic vessels  Thoracic duct  Left subclavian vein  SUPERIOR VENA CAVA

Antigens & Antibodies ANTIGEN (foreign substance in your body) Glycoprotein chain within plasma membrane of foreign substance Your body recognizes the chain as being “non self” Examples.  bacteria  foreign human cells (transplant tissue)  cancer cells

ANTIBODY Proteins capable of combining with & neutralizing antigens Produced by “B Cells” (lymphocytes/ white blood cells) Secreted into blood & lymph Recognize antigen because they have receptors on surface that fit like a “lock & key” Specific antibody for each antigen

How they work ANTIBODY + ANTIGEN  INACTIVE (foreign invader) COMPLEX * Lock & Key fit (like enzymes)… very specific! AGGLUTINATION: clumped or “agglutinated” antigens

Immunity (how your body responds) Lymphocytes exposed to antigen (naturally or through vaccine) Manufacture antibodies Some antibodies remain in lymph nodes forever as memory cells Capable of producing antibodies during a future invasion of same antigen