Lymphatic System & Immune Response

LYMPHATIC SYSTEM Network of tissues and organs that help rid the body of toxins & waste Includes: Lymphatic vessels Lymph nodes Lymphoid organs Thymus Tonsils Spleen

Cardiovascular / Lymphatic Loop Osmotic pressure pushes liquid out of the capillaries Extracellular fluid is renewed and cells are bathed in nutrients/hormones/gases Pressure returns fluid back into capillaries --- some goes into lymphatic vessels Fluid is called lymph and travels to lymph nodes where macrophages remove abnormal cells and microbes Lymph ducts join with veins and return lymph back to blood

Lymphatic Vessels Occur adjacent to vascular system vessels Contain valves to prevent back-flow Larger lymphatics empty into veins Thoracic duct – most of the lymph is returned to circulation Cisterna Chyli – saclike portion of thoracic duct that delivers lymph from lower limbs, pelvis, and abdomen Right lymphatic duct – returns lymph from upper right limbs, neck and chest

Lymph Nodes Contain phagocytes and macrophages to remove bacteria, debris, and other antigens in the lymph Scattered throughout the lymphatic system What does a swollen lymph node indicate?

Implications in Breast Cancer https://www.youtube.com/watch?v=cSkxycrC9lE

Lymphocytes leave the blood and enter node Lymphocytes are produced B cells and plasma cells Rich in B cells

Lymphatic Nodules Found in connective tissue under lining of digestive, urinary and respiratory systems The lymph in nodules encounters macrophages/lymphocytes and microbes in the lymphs are removed Ex. Tonsils, Peyers Patches

The Spleen Largest lymphatic organ in the body Red pulp White pulp Phagocytes remove abnormal RBC’s and antigens Lymphocytes start producing antibodies Contain trabecular arteries White pulp Contain central arteries

Immune Response Innate vs Adaptive Memory, Specificity, Self-Tolerance B cells vs T cells T cells Helper cells Cytotoxic cells B cells Memory vs Plasma cells Form antibodies (immunoglobulins)

Clonal Selection

Antibodies for Cancer? https://www.youtube.com/watch?v=5AXApBbj1ps