Term
| what is the lympathatic system? |
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Definition
| works together to keep us healthy + alive |
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Term
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Definition
| flows through lymphatic vessels(resembles plasma, contains much lower concentration of suspended proteins) |
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Term
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Definition
| lymphatics, carry lymph from peripheral tissues to the venous system in all parts of the body except the CNS |
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Term
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Definition
| endothelium permits fluid to flow into the capillary |
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Term
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Definition
| connected to lymphatic vessels (lymph nodes, spleen, & thymus |
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Term
| what does the lymphatic system do? |
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Definition
-part of the body's immune response to pathogens, lymphocytes are primary cell type
-prevents fluid build-up in tissues
(these 2 functions occur stimultaneously-filter system) |
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Term
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Definition
capillary dynamics:
fluid movement between capillary & tissue(interstitial space), outward @ beginning of capillary & inward @ end of capillary due to osmosis, concentration gradients from proteins ect.
-slightly more fluid pushed out than returned |
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Term
| what happens to the excess fluid? |
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Definition
picked up by lymphatic capillaries
-blind ends have one-way valves; fluid enters but cannot flow back into tissue
-fluid is now lymph fluid
-capillaries-larger vessels-two large ducts that empty into venous system
*left lymphatic(thoracic)duct-near l. internal jugular vein(drains 3/4 of body)
*r. lymphatic duct-near r. internal jugular vein, drains 1/4 of body
-amount of fluid returned is large(3-4 liters/day)
-fluid is moved by valves & nearby tissues(just like veins) |
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Term
| what happens if lymph vessel is blocked? |
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Definition
| can lead to edema(elephantiasis) |
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Term
| how is lymph fluid filtered? |
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Definition
| lymph nodules & nodes in route to venous system |
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Term
| what are the purposes of nodules and nodes? |
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Definition
| to remove & destroy pathogens & alert immune system |
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Term
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Definition
| masses of connective tissue & lymphocytes, w/out fibrous capsule located near body openings & in GI tract(tonsils, lining of appendix) |
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Term
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Definition
| masses of connect tissue & lymphocytes, w/ capsule located @ junctions of the system(neck, armpit, groin) & around important organs to prevent spread(pelvic & abdominal nodes) |
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Term
| what resides in the nodules & nodes? |
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Definition
| majority of lymphocytes do, to destory pathogens, few normally circulate |
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Term
| what happens when you have an infection? |
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Definition
-causes extra lymphocytes to gather in node or nodule results in swelling
-enlarged nodes can also indicate presence of cancer--cancer cells spread through lymph vessels & become trapped(breast cancer spreads to nodes under arm) nodes swell but are not painful |
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Term
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Definition
performs a similar filtering role for the blood
-filters out aging RBCs
-contains large #s of lymphocytes & phagocytes to destroy pathogens
-enlarged during infections(more cells) & is easily ruptured even under normal circumstances
(often removed bc it can't be repaired; removal does not cause any impairment bc liver takes over function |
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Term
| where is the thymus and what does it do? |
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Definition
located above the heart, in front of aorta & trachea
-doesn't directly attack pathogens, has indirect role helps lymphocytes learn to recognize specific pathogens(maturation)
-important in childhood but not so much in adulthood |
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