Dab tsi yog cov txheej txheem hemostatic hauv ntau hom hlab ntsha?
Raws li tus neeg muag khoom hauv thaj chaw hemostasis, kuv tau tshawb xyuas cov txheej txheem uas cov hlab ntsha sib txawv teb rau kev raug mob. Kev nkag siab txog qhov sib txawv no yog qhov tseem ceeb rau kev tswj ntshav kom zoo.
Muaj peb hom hlab ntsha tseem ceeb: cov hlab ntsha, cov hlab ntsha, thiab capillaries. Txhua tus muaj cov yam ntxwv tshwj xeeb uas cuam tshuam rau lawv cov txheej txheem hemostatic.
Cov hlab ntsha
Cov hlab ntsha nqa oxygenated ntshav tawm ntawm lub plawv. Lawv muaj cov phab ntsa tuab, cov leeg nqaij uas ua kom muaj zog vasoconstriction. Thaum cov hlab ntsha puas lawm:
Vasoconstriction:Cov nqaij leeg nyob rau hauv cov phab ntsa arterial tau cog lus tam sim ntawd, nqaim lub nkoj thiab txo cov ntshav ntws mus rau qhov chaw raug mob.
Platelet activation thiab plug tsim:Platelets ua raws li cov collagen nyob rau hauv cov hlab ntsha puas tsuaj ntawm von Willebrand yam, ua kom qhib tau thiab sib sau ua ib ntus ntsaws.
Coagulation cascade:Cov ntaub so ntswg tso tawm los ntawm cov hlwb puas pib txoj hauv kev extrinsic, ua rau thrombin tiam thiab tsim fibrin. Qhov no tsim ib qho chaw ruaj khov uas tuaj yeem tiv taus qhov siab ntawm cov ntshav ntws.
Cov leeg
Cov leeg nqa cov ntshav deoxygenated rov qab mus rau lub plawv. Lawv muaj cov phab ntsa nyias thiab txo cov ntshav siab piv rau cov hlab ntsha. Thaum cov hlab ntsha puas lawm:
Vasoconstriction:Qhov no tshwm sim tab sis yog tsawg tshaj li nyob rau hauv cov hlab ntsha vim lub thinner muscular txheej.
Platelet activation thiab coagulation:Tib lub hauv paus mechanisms ntawm platelet plug tsim thiab coagulation cascade activation tshwm sim. Cov ntaub so ntswg los ntawm cov hlab ntsha puas ntsoog pib txhaws.
Clinical Note:Thaum cov txheej txheem physiological hemostatic nyob rau hauv cov leeg zoo ib yam li cov hlab ntsha, cov ntshav qis qis hauv cov hlab ntsha tuaj yeem ua rau cov kab mob thrombosis (xws li cov hlab ntsha sib sib zog nqus thrombosis) thaum muaj kev pheej hmoo xws li stasis lossis hypercoagulability. Qhov no yog ib qho mob sib txawv ntawm ib txwm hemostasis.
Capillaries
Capillaries yog cov hlab ntsha me tshaj plaws, suav nrog ib txheej ntawm cov hlwb endothelial uas nyob ib puag ncig los ntawm lub hauv paus membrane. Lawv tsis muaj cov leeg du thiab yog li tsis tuaj yeem ua rau vasoconstriction. Thaum lub capillary puas lawm:
Endothelial teb:Cov hlwb puas endothelial nthuav tawm cov collagen hauv qab, ua rau platelet adhesion.
Platelet plug tsim:Platelets ua raws li qhov raug subendothelium thiab tsim ib lub microscopic plug.
Coagulation:Lub coagulation cascade yog qhib rau hauv zos. Vim qhov me me ntawm capillaries, platelet plug thiab fibrin tsim feem ntau txaus los kaw qhov raug mob yam tsis tas yuav tsum muaj vasoconstriction.
Cov ntaub ntawv
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Guyton thiab Hall Phau Ntawv Qhia Kev Kho Mob Physiology.
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Robbins thiab Cotran Pathology Basis ntawm Kab Mob.
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Harrison's Principles of Internal Medicine.