BMS Lab L4 Lymphatic System Notes PDF

BMS Lab L4 Lymphatic System Notes Lymph - Tissue/ interstitial fluid that enters the lymphatic vessels Lymphatic System - Drainage system accessory to the venous system - Removes larger particles that escape into tissue fluid - Closed end vessels Functions - Reabsorbs excess interstitial fluid: - Re...

BMS Lab L4 Lymphatic System Notes Lymph - Tissue/ interstitial fluid that enters the lymphatic vessels Lymphatic System - Drainage system accessory to the venous system - Removes larger particles that escape into tissue fluid - Closed end vessels Functions - Reabsorbs excess interstitial fluid: - Returns it to the venous circulation - Maintain blood volume levels - Prevent interstitial fluid levels from rising out of control - Transport of dietary lipids: - Lacteals - Drain into larger lymphatic vessels - Into bloodstream - Lymphocyte development and immune response Components of the LS - Lymph - Lymphatic vessels - - - L. capillaries - L. vessels - L. trunks - L. ducts Lymphatic organs - Thymus - Tonsils - Spleen - Lymph nodes Lymphatic cells Lymphatic Capillaries - Anatomic features: - Blind end (closed ended, not connected) - Single layer of overlapping endothelial cells - High permeability, more than blood vessels - Present in the interstitial space of vascular structures - Absent in avascular structures - brain, spinal cord, and bone marrow Lacteals - Lymphatic capillaries in the small bowel - Absorb: - Interstitial fluid - Dietary lipids - Liposoluble vitamins - ADEK - Chyle: milky colored lymph due to emulsified fats + lymph Lymphatic vessels - Anatomic features: - 3 layered wall: thinner than veins - More valves present than in veins - Interposed by lymph nodes at intervals Lymph trunks - Formed by confluence of many efferent lymph vessels - R/L jugular trunks - R/L subclavian trunks - R/L bronchomediastinal trunks - Cisterna chyla - inferior to the aortic hiatus of the diaphragm - Intestinal trunk - R/L lumbar trunks - R/L external and internal iliac lymph trunks Lymphatic ducts - Right lymphatic duct - Formed by the union of the: - R jugular trunk - R subclavian trunk - R broncho-mediastrinal trunk - Ends by entering the right venous angle, union of: - R internal jugular vein - R subclavian vein - Thoracic duct - Begins in front of L1 as a dilated sac, the cisterna chyli - abdominal origin of the thoracic duct - Formed by: - L/R lumbar trunks - Intestinal trunk - Enters thoracic cavity and ascends - Goes upwards and swings left at T5 - At root of neck, turns laterally - Before termination, it receives: - L jugular subclavian trunk - L broncho-mediastrinal trunk - Arches forward and descends to enter the L venous angle - Venous = union of L internal jugular vein + L subclavian vein Drainage pattern Lymphatic cells - Aka lymphoid cells - In both lymphatic and cardiovascular system - Elicit immune response - Types: - Macrophages - Epithelial cells - Dendritic cells - Lymphocytes Lymphatic organs - Primary (2): (1 to 2) - Bone marrow - Thymus gland - Secondary (LLS): - Lymph nodes - Lymphe nodules - Spleen Lymph nodes - Small, round, oval - Along pathways of lymph vessels - 1 - 25 mm - Typically found in clusters - Features: - Bean shaped body - With afferent vessels (entering at the periphery) and efferent lymph vessels (emerging at the hilus) - Arranged in groups, along the blood vessels OR the flexural side of the joint - Divided into superficial and deep groups Regional lymph drainage - Sentinel lymph node - regional node where the lymph of an organ drains into first, first node to receive drainage directly from a tumor - Portal of metastasis - cancer - Ex. the breast Spleen - Location - Left epigastric region - Bt 9-11th rib - Largest lymphatic organ - White pulp: lymphatic tissue consisting of lymphocytes around arteries, involved in immune response - Red pulp: venous sinuses filled with blood and cords of lymphatic cells, such as lymphocytes and macrophages, involved in blood storage and filtration - Function: - Fight invading germs in the blood - Filters the blood and removes old/damaged RBCs - Splenic sequestration - controls the level of RBCs (WBCs, RBCs, platelets) Thymus - 2 elongated lobes - Large organ in the fetus - In the thoracic cavity, behind the sternum - Secretes lymphopoietin (Thymic Stromal Lymphopoietin- TSLP) - Interleukin 7 like cytokine - expressed mainly by epithelial cells - Activates dendritic cells to promote T helper (Th) 2 immune responses Lymphatic nodules - Oval clusters of lymphatic cells with some extracellular matrix - NOT surrounded by a connective tissue capsule - Filters and attacks antigens - Larger group of lymphatic nodules: - Mucosa associated lymphatic tissue (MALT) - Mucosa of the small intestine, primarily in the ileum (Peyer Patches) - Peyer patches are lymphatic tissue nodules that are similar to lymph nodes EXCEPT they are not surrounded by a connective tissue capsule - Appendix - Tonsils - Walls of the bronchi Conditions associated to the LS - Lymphangitis - Filariasis - Lymphedema - Lymphadenopathy - Lymphomas - Tonsillitis - Splenomegaly - - - - - - Lymphangitis - Inflammation of the lymph vessels - Bacteria: streptococcus pyogenes (most common) - Red streaks thru skin Filariasis - Mosquito carrier - Larvae mature into worms and spread thru the lymphatic vessels Lymphedema - Build up of lymphatic fluid in the interstitial tissue - Tight clothing/jewelry could be used on affected limb Lymphadenopathy - Disease of the lymph nodes - Nodes become swollen/enlarged Lymphomas - Cancer from lymphocytes in the lymph nodes OR lymphatic tissue in the organs - Risk factors: HIV, HEP, EBV (epstein-barr virus) infections, and NASH (nonalcoholic steatohepatitis) (leads to liver cirrhosis (scarring)) or liver cancer Tonsillitis - Infection of the pharyngeal tonsils - Tonsils are swollen - Fever and pain during swallowing - - Treatment: surgical removal of tonsils (tonsillectomy) Splenomegaly - Enlarged spleen