The Lymphatic System Flashcards
What makes up the lymphatic system?
Lymph fluid, vessels lymphatics, cells lymphocytes, tissue MALT GALT BALT, Lymphoid organs: nodes, tonsils, adenoids, thymus + spleen
Where does the fluid lymph come from?
20L water pushed out via osmotic pressure, 17 reabsorbed back to venous, 3 left in interstitial space (half the blood volume) + taken up by lymphatic capillaries (loosely overlapping endothelial cells). Pressure outside lymphatic capillaries is higher so enters the capillaries via one-way valves = then fluid called lymph. Stops oedema.
Where does the right lymphatic duct connect to the blood supply?
upper right thoracic quadrant, arm, right side of head –> internal jugular vein
Where does the left larger thoracic duct connect to the blood supply?
subclavian vein
What is a lymph node and what is its function?
~700, inspection of fluid by lymphocytes, afferent lymphatic vessels enter via convex surface + efferent lymphatics leave via hilum. Trigger macrophages release + further immune responses, Inflammation: when overwhelmed with infection (lymphadenopathy) germinal centres fill with lymphocytes = swelling, pain, Contain APC = present Ag to naive T cells for activation, Traps Ag, present to T cells
Describe what the spleen is
Largest lymphatic organs. Very rich blood supply. Filters blood: removal/destruction of old RBC, platelets + retrieval of iron from RBCs. Immune: APC, activation/proliferation B + T cells, removal of macromolecular Ag in blood. Rupture = exsanguination = death. Can enlarge = systemic infection
What does MALT stand for?
Mucosa associated lymphoid tissue, Mucous membrane outside of lymph capillary, e.g. Tonsils, Peyers patches, distal portion of small intestine, check point of GI track, Appendix, lymph tissue
What is the thymus?
Superior mediastinum, Fully formed at birth, involutes after puberty, late teens = mostly fat, Role = maturation of bone marrow derived stem cells into immunocompetent T cells = thymic cell education
What happens when the spleen is removed?
Removal = liver/bone take over removing RBCs, increases risk of infection, increases risk of DVT = increased platelets. Spleen
What cells is inflammation mediated by?
Neutrophils and macrophages
What is innate immunity?
Non specific, external barricade, mucus, enzymes, fever, neutrophils, macrophages, natural killer, complement cascade
Outline humoral immunity
Acquired, specific, systemic, has memory, B cells producing Abs, complement proteins, antimicrobial peptides
What is cell mediated immunity?
Does not involve Abs. APCs, activation of phagocytes, cytotoxic T-cells
What is adaptive immunity?
Covers cell mediated and humoral immunity
Name the tonsils
Pharyngeal, palatine, lingual
