Indima Yama-Leukocyte Esistimu Yokuzivikela Emzimbeni
Ama-leukocyte, noma amangqamuzana amhlophe egazi, adlala indima ebalulekile ekugcineni impilo nokuvikela umzimba ezifweni ezahlukahlukene. Ngaphandle kohlelo lwe-leukocyte olusebenzayo, imizimba yethu ingaba sengozini yokutheleleka ngamagciwane abangela izifo, njengebhaktheriya, amagciwane, isikhunta, kanye nezinambuzane. Ama-leukocyte asebenza njengohlelo lokuzivikela oluyinhloko, eqaphela futhi elwa nezinto ezibangela izifo ngendlela eyinkimbinkimbi nehlelekile. Kulesi sihloko, sizoxoxa ngendima yama-leukocyte ohlelweni lokuzivikela, okuhlanganisa izinhlobo ezahlukene zama-leukocyte kanye nezindlela zawo zokusebenza.
Izinhlobo zama-Leukocyte
Ama-leukocyte angahlukaniswa ngezinhlobo eziningana ngokusekelwe emsebenzini wawo kanye nezici zawo zokwakheka:
1. Ama-Neutrophil: Uhlobo oluningi kakhulu lwama-leukocyte egazini futhi lusebenza njengomugqa wokuqala wokuzivikela ekuthelelekeni ngamagciwane kanye nesikhunta. Ama-Neutrophil angahamba ngokushesha aye endaweni yokutheleleka futhi enze i-phagocytosis, inqubo yokugwinya nokubhubhisa amagciwane.
2. Ama-lymphocyte: Ahlukaniswe ngamaqembu amabili ayinhloko: ama-T cell nama-B cell. Ama-T cell adlala indima empendulweni yamasosha omzimba wamaseli ngokubulala amaseli athelelekile noma ukusiza ekulawuleni impendulo yamasosha omzimba. Ama-B cell, ngakolunye uhlangothi, anesibopho sokukhiqiza ama-antibodies empendulweni yamasosha omzimba yama-humoral.
3. Ama-monocyte: Ngemva kokujikeleza egazini, ama-monocyte angathuthela ezicutshini futhi ahlukane abe ama-macrophage noma amaseli e-dendritic. Womabili adlala indima ekuvezeni i-phagocytosis kanye ne-antigen kumaseli e-T, okuyisihluthulelo sokuqala impendulo yokuzivikela komzimba eguquguqukayo.
4. Ama-Eosinophil: Ahilelekile ekuphenduleni komzimba ezifweni ezibangelwa yizinambuzane futhi adlala indima ekuphenduleni kokungezwani komzimba. Ama-Eosinophil anekhono lokubhubhisa amagciwane ngokukhulula ama-enzyme alimaza ulwelwesi lwe-microorganism.
5. Ama-Basophil: Nakuba engemaningi kakhulu, ama-basophil adlala indima ekuphenduleni kokungezwani komzimba kanye nokuvuvukala. Akhipha i-histamine namanye amakhemikhali alawula ukusabela kokuvuvukala.
Indlela Yokusebenza Ye-Leukocyte
Ama-leukocyte asebenza ngezindlela ezahlukene ukuvikela umzimba ekuthelelekeni nasezifweni. Nazi ezinye zezindlela eziyinhloko abazisebenzisayo:
I-Phagocytosis
I-Phagocytosis inqubo lapho ama-leukocyte afana nama-neutrophils nama-macrophage egwinya futhi abhubhise amagciwane. Le nqubo ihilela izinyathelo eziningana, okuhlanganisa i-chemotaxis (ukuhamba uye endaweni yokutheleleka okuqondiswa izimpawu zamakhemikhali), ukubopha ku-pathogen ngama-receptor athile, kanye nokufakwa ngaphakathi kwe-pathogen ku-phagosome. Ngaphakathi kwe-phagosome, i-pathogen ihlaselwa futhi ibhujiswe ngama-enzyme e-lysosomal.
Ukukhiqizwa Kwama-Antibody
Ama-lymphocyte e-B anesibopho sokukhiqiza ama-antibodies aqaphela futhi anciphise amagciwane. Le nqubo iqala lapho ama-B cell ehlangana ne-antigen ethile. Ama-B cell abe esesebenza futhi ahlukane abe amaseli e-plasma, akhiqiza inani elikhulu lama-antibodies. Lawa ma-antibodies asebenza ukubopha kuma-antigen kuma-pathogen, ewaphawula ukuthi abhujiswe ngezinye izindlela ezifana ne-complement noma i-phagocytes.
Ukusebenza kwe-T Lymphocyte
Ama-T lymphocyte anezinhlobo eziningana ezinemisebenzi ehlukene. Ama-T cell asizayo (i-CD4+) akhipha ama-cytokine avuselela amanye amaseli omzimba futhi athuthukise impendulo yomzimba. Ama-T cell ane-cytotoxic (i-CD8+) ayaqaphela futhi abulale amaseli atheleleke ngegciwane noma anomdlavuza. Ukusebenza kwamaseli e-T kuqala ngokuqaphela i-major histocompatibility complex (i-MHC) kumaseli aveza ama-antigen (ama-APC), njenge-macrophages noma amaseli e-dendritic.
Ukukhishwa kwe-Cytokine
Ama-cytokine abonisa ama-molecule akhishwa ama-leukocyte ukuze axhumane futhi alawule izimpendulo zomzimba. Angadonsela amangqamuzana omzimba endaweni yokutheleleka (i-chemotaxis), athuthukise umsebenzi we-phagocytic, futhi alawule ukukhiqizwa kwama-antibody. Izibonelo zama-cytokine zifaka phakathi ama-interleukin (ILs), ama-interferons (IFNs), kanye ne-tumor necrosis factor (TNF).
Impendulo Yomzimba Engokwemvelo Neziguquguqukayo
Ama-leukocyte adlala indima ebalulekile kuzo zombili izinhlobo zezimpendulo zomzimba: ezingokwemvelo neziguquguqukayo. Impendulo yomzimba yomzimba iyindlela yokuqala yokuzivikela futhi yenzeka ngokushesha ngemva kokutheleleka. Ihlanganisa izithiyo zomzimba (isikhumba kanye ne-mucosa), amaseli e-phagocytic (ama-neutrophils, ama-macrophage), amaseli e-natural killer (NK), kanye namaprotheni e-serum njenge-complement.
Ngokuphambene nalokho, impendulo yokuzivikela komzimba eguquguqukayo icacile kakhulu futhi ithatha isikhathi eside ukukhula. Ihilela ukuqashelwa kwe-antigen ethile ngama-B kanye nama-T lymphocyte, ukwakheka kwenkumbulo yokuzivikela komzimba, kanye nokukhiqizwa kwama-antibodies. Impendulo eguquguqukayo ibonakala ngokuhlukile kwayo kanye nekhono "lokukhumbula" amagciwane ahlangane nawo ngaphambilini, ngaleyo ndlela inikeze isivikelo esisebenza kahle kakhulu ekuthelelekeni okulandelayo.
Ukulawulwa kwe-Homeostasis
Ngaphandle kokulwa nokutheleleka, ama-leukocyte asebenza futhi ekugcineni i-homeostasis kanye nokulungiswa kwezicubu. Ama-macrophage, isibonelo, adlala indima ekususeni amangqamuzana afile kanye nezinye izinsalela ezicutshini kanye nokusekela izinqubo zokulungisa ngokukhulula izici zokukhula. Ama-eosinophil nama-basophil adlala indima ekuxazululeni impendulo yokuvuvukala edingekayo ukuze kuncishiswe ukulimala noma ukuhlaselwa yi-pathogen.
Ukuphazamiseka Komsebenzi We-Leukocyte
Ukuphazamiseka ekusebenzeni kwe-leukocyte kungabangela izifo ezahlukahlukene. Isibonelo, i-neutropenia yisimo sezokwelapha lapho inani lama-neutrophil lehla khona, okwenza umuntu abe sengozini enkulu yokutheleleka ngamagciwane kanye nesikhunta. Izifo zokuzivikela komzimba, njenge-systemic lupus erythematosus, zenzeka lapho ama-leukocyte ehlasela izicubu zomzimba ngenxa yokwehluleka ukuzazi kubantu abangebona bona. Iningi lomdlavuza wegazi, njenge-leukemia, liphinde lihilele ukukhiqizwa ngokweqile kwama-leukocyte noma ukungasebenzi kahle kwawo.
Ngakolunye uhlangothi, amanye amagciwane anezindlela zokugwema noma ukucindezela impendulo yomzimba yama-leukocyte. Igciwane le-HIV, isibonelo, lihlasela amaseli e-T asizayo futhi lilimaza isimiso somzimba sokuzivikela, okuholela kwi-AIDS.
Isiphetho
Ama-leukocyte ayizingxenye ezibalulekile zesimiso somzimba sokuzivikela, abhekene nokubona, ukuhlasela, nokubhubhisa amagciwane. Asebenza ngezindlela ezahlukahlukene eziyinkimbinkimbi nezihlelekile, okuhlanganisa i-phagocytosis, ukukhiqizwa kwama-antibody, ukusebenza kwamaseli e-T, kanye nokukhululwa kwamaseli e-cytokine. Ngaphezu kwalokho, ama-leukocyte adlala indima ekugcineni i-homeostasis kanye nokulungiswa kwezicubu. Ukuphazamiseka ekusebenzeni kwama-leukocyte kungaholela ezifweni ezahlukahlukene, okugqamisa ukubaluleka kwala maseli ekugcineni impilo kanye nokulwa nezifo. Ngokuqonda kangcono indima kanye nezindlela zama-leukocyte, singakha izindlela zokwelapha ezisebenzayo zokuqinisa impendulo yomzimba yomzimba.
