Comprehensive Overview of Lymphatic System Lymph Lymphatic Vessels Lymphoid Tissues Lymphoid Organs Tonsils Thymus Spleen MALT Appendix Lymphatic Capillaries Lacteals Superficial Lymphatics Deep Lymphatics Lymphatic Trunks Thoracic Duct Right Lymphatic Du

Comprehensive Overview of Lymphatic System Lymph Lymphatic Vessels Lymphoid Tissues Lymphoid Organs Tonsils Thymus Spleen MALT Appendix Lymphatic Capillaries Lacteals Superficial Lymphatics Deep Lymphatics Lymphatic Trunks Thoracic Duct Right Lymphatic Duct Cisterna Chyli Lymphedema Immunity Innate Immunity Adaptive Immunity Lymphocytes T Cells B Cells NK Cells Plasma Cells Antibodies Immunoglobulins Antigens Cytotoxic T Cells Helper T Cells Memory T Cells Suppressor T Cells Inflammatory T Cells Humoral Immunity Cell-Mediated Immunity Immune Response Immunological Surveillance Pathogens Disease-Causing Organisms Exam Questions Verified and Provided with A+ Graded Rationales Latest Updated 2026 pathogens disease causing organisms lymphocytes primary cells of the lymphatic system respond to invading pathogens (bacteria or viruses), abnormal body cells (virus infected cells or cancer cells), and foreign proteins (toxins released by some bacteria) lymphatic system cells, tissues, and organs responsible for defending the body. acts against pathogens and internal threats immunity ability to resist infection and disease two forms of immunity innate (nonspecific) - numerous adaptive (specific) - lymphocytes immune response an adaptive, specific, defense provided by lymphocytes Parts of lymphatic system lymph lymphatic vessels or lymphatics lymphoid tissues lymphoid organs lymphocytes lymph fluid that resembles plasma but contains a much lower concentration of suspended proteins lymphatic vessels carry lymph from peripheral tissues to venous system lymphoid tissues and organs tonsil, thymus, spleen, MALT (mucosa associated lymphoid tissue) in digestive, respiratory, urinary, and reproductive tracts, appendix lymphatic capillaries smallest lymphatic vessels cells act as a one way valve: contain overlapping endothelial cells and an incomplete basement membrane to allow fluid, solutes, viruses, bacteria, and debris to enter but not leave how do lymphatic capillaries differ from blood capillaries originate as pockets rather than forming continuous tubes have larger diameters have thinner walls typically have a flattened or irregular outline in sectional view lacteals lymphatic capillaries in the small intestine that are important in the transport of lipids absorbed by the digestive tract small lymphatic vessels lymph flows here from the capillaries low pressure with valves to prevent back flow lymph vessels are a pale golden color (arteries-red, veins-blue) and are more abundant in tissue, but much smaller superficial lymphatics collect lymph from lymphatic capillaries. located in subcutaneous layer of skin, areolar tissues of mucous membranes lining the digestive, respiratory, urinary, and reproductive tracts areolar tissues of the serous membranes lining the pleural, pericardial, and peritoneal cavities deep lymphatics collects lymph from lymphatic capillaries accompany deep arteries and veins supplying skeletal muscles and other organs of the neck, limbs, and trunk, and the walls of visceral organs lymphatic trunks large vessels formed by converging superficial and deep lymphatic vessels thoracic duct collects lymph from the body inferior to the diaphragm and from the left side of the body superior to the diaphragm trunks empty here right lymphatic duct smaller of the two ducts collects lymph from the right side of the body superior to the diaphragm cisterna chyli expanded, sac-like chamber at the base of the thoracic duc receives lymph from the inferior part of the abdomen, the pelvis, and the lower limbs by way of the right and left lumbar trunks and the intestinal trunkt lymphedema accumulation of interstitial fluid due do a blockage of the lymphatic drainage from a limb, causing it to become swollen and distended danger from persistent swelling connective tissues lose their elasticity and swelling become permanent interstitial fluids are essentially stagnant, so toxins and pathogens can accumulate and overwhelm