Bio 224 lymphatic system Flashcards
(97 cards)
Lymphatic system
Fluid homeostasis, extracelular fluid drains into lymphatics back to cardio system
Immune funtions
WBC and filtration
Absorption of dietary fat
fat are too large to pass between endotherlial cells of blood capilaries
Lymphatic vessles and circulation
-low pressure circuit( no main pump)
-Valves prevent lymph from flowing backward
- contracting muscles massage lumph up toward heart
- Driven in part by contraction of smooth muscle
Cells of lymphatic capillary wall are __ joined and are able to ___ and __
NOT, Open and close
Lymphedema
Removal of lymphatic vessles during surgery or blockage of vessels from pathogens such as parasites
- Prevent vessels from transporting fluid back into cardio system
Fluid that leaks from blood capillaries _____ interstitial fluid pressure; forces ___________ apart
Increases, lymphatic endotherilal cells apart
Leukocytes
Lymphoid organs house
Macroopahges
mature moncytes; very active phagocytes
B and T lympocytes
Agranulocyte with diverse immune functions
Mucosa-associated lymphatic tissue (MALT)
Loosley organized clusters of lymphoid tissue; protect mucous membranes; which are exposed number of pathogens ( Tonsils)
Red pulp
contain macrophages that destroy old erythrocytes
Spleen
largest lymphoid organ in body
Thymus
-T cell school,
-release thymosin that convert b cell into t cells
- cortex contains densely packed t maturing cells
White pulp
filters pathogens from blood and contains leukocytes and dendritic cells
Medulla
Site of destruction t cells that could react to bodys own cells
1 line of defense ( SURFACE BARRIERS
Skin is resistant to mechanical stresses because of serval layers of epithelial cell filled with KERATIN
Sebum
oil
- sebaceous galnds secrte in which is slightly acidic pH
1 line of defense (MUCOUS MEMBRANE)
secrete products that discourage pathogen invasion, namely, sticky substance mucus
- Mucus traps pathogens and protects underlying cells from chemical and mechanical truama
2 line of defense (INNATE IMMUNITY)
rapid ( first 12 hours) , NON-SPECIFIC response to pathogenic invasion and trauma
Macropahge
activated by certain molecules present on pathogens, chem. secrted by damaged cells and signalas from cell of adaptive immunity
Which cells are the first to respond to cellular injury
Activated local macrophages
what else can neutrophils do ?
- ingest many cell type; particularly effective at destroying bacterial pathogens
- relsease contents onto large pathogens to damage thier plasma membranes
Neutrophils
-most numerous granulocytes
-highly effective phagocytes
- Kill their ingested pathogens with chemicals such as hydrogen peroxide, hypochlorous acid and lysozyme