Cornea - omunye izingxenye ebaluleke kakhulu ehlweni lomuntu

Omunye izingxenye ezibalulekile kakhulu Iso lomuntu liwumsebenzi cornea, esivikela ke ekulimaleni kanye nezifo. Nokho, lona abasengozini khulu, okubenza babe sengozini yezifo ezihlukahlukene.

Cornea ivikela phambi ingxenye yalokho surface Dome emise elingaphandle iso; Iqukethe akukho imithambo yegazi kuyadingeka ukuze awunikeze iningi izicubu womuntu, futhi uhluke homogeneity optical. Ukuze qualitatively refract ukukhanya, i-cornea idinga ukuba sobala, khona izitsha ezincane kakhulu ngeke iphazamise le nqubo. I-cornea yezokubona esweni kuyinto 43 diopters. Amandla akhe elamukelayo ikakhulu kusukela izinyembezi futhi amahlaya aqueous phambili ekamelweni.

Cornea ngokuvamile kuqhathaniswa ne ingilazi amahora, ifakwe luhlaka, kusukela ugobile cornea ngokwayo kancane sibe sikhulu kunesihlalo ugobile sclera. Cornea siqukethe izingqimba ezinhlanu, ngalunye lwenza umsebenzi walo obalulekile: epithelium, ulwelwesi Descemet sika, ungqimba Bowman sika, endothelium, stroma.

Kumiswa kusuka amaseli flat zikanhlangothiningi - ungqimba Front - epithelium. Okulandelayo wembozwe Bowman - eyohlobo structureless phambi ipuleti umngcele. Empeleni uqobo corneal stroma izidakamizwa ibizwa ngokuthi, yakhiwa mncane kakhulu amapuleti zezinzwa, kushintshana nomunye equkethe sebuningini fibrils ezicashile. Ekhuluma ewukuhlakanipha okwenziwe nemiyo ingcina izenzo mucoid kokuba ukubunjwa yayo sulfogialuronovuyu acid enikeza obala cornea. I stroma aluqukethanga imithambo yegazi, futhi kakhulu zisimama kancane kancane. igobolondo Descemet, noma ulwelwesi, ngemuva, elicinene kakhulu, umngcele ipuleti, fibrils yayo kuqukathe impahla ekhethekile lapho nsé collagen; ke regenerates kahle. Endothelium (epithelium corneal noma ngemuva) - ungqimba aminyene amaseli prismatic flat olunezinhlangothi ohlanganisa. Lesi sendlalelo unesibopho obala we-cornea kanye akuyona ibuyiselwe.

Isakhiwo cornea kukhona 80% amanzi, 18% of the-collagen esichazayo, mayelana 2% mucopolysaccharides, lipids, amaphrotheni, i-C amavithamini, B, et al. Ingabe i-cornea abadala iqukethe esincane kakhulu amavithamini umswakama, it is wabusa globulin amaprotheni amafraktjhini futhi imali calcium nosawoti kanye lipids. Umphumela walezi zinguquko ushintsho ukwedlulela cornea (the limbus) ku sclera - izingqimba scleral baqala "hang" ku-cornea futhi ibonakala ngakho ngokuthi gerontoxon encishisiwe ukuzwela corneal namandla alo yezokubona. Ngaphezu kwalokho, kakhulu ziyancipha permeability ukuba iso amaconsi, yokugcoba kanye nezakhi.

Ukuzwela kwama-cornea (innervation) emsipheni trigeminal. Ikakhulukazi eziningi kwalapho kuhlangana khona izingqimba eligcizelela ukubukeka kwangaphandle, komncane - e endothelium. Ngo ezisanda kuzalwa, i-cornea akazwelani ngenxa ukuthuthukiswa ongaphelele izinzwa cranial, futhi lapho ngineminyaka engu-unyaka owodwa, ukuzwela yayo cishe kuyafana abadala.

Ngenxa yokuthi i-cornea - udonga lwangaphandle iso, kuba njalo nabo imvelo bangaphandle. Ngakho-ke, kuneendlela ekhethekile ukuvikela emiphumeleni elimazayo evela ngaphandle ukulimala:

1. lokuvala Reflex samehlo;
2. Siwasebenzise nabenzeli corneal eziyingozi esebenzisa uketshezi lacrimal;
3. Kuvuka lokusheshako kanye ephelele epithelium.

sezifo ezinkulu kakhulu cornea yilezi: kwezinso zentuthuko, dystrophic nezinqubo ukuvuvukala (sclerites keratitis) kanye izimila.

amehlo keratitis noma corneal ukuvuvukala pathologies phakathi ezivamile. Keratitis kukhona exogenous futhi endogenous. Isikhathi esining impela, ngemuva kokuxinwa keratitis is ingaphazamisi we-cornea of kobukhulu obuhlukahlukene. Ngokusho ukushuba ifu nokubaluleka kwalo ukuhlukanisa efwini ngesimo ale nkinga, izindawo kanye namafu. Thorn kuyinto ingaphazamisi nzile cornea, okuyinto ngenxa nezibazi, corneal ayebusa ingxenye noma lonke cornea. Spot - a eziphikelelayo okukhulu opacity corneal nge imiphetho ebukhali azungeze noma maphakathi. Cloud kukhawulwe esilufifi grey umbala okuyinto neze ezabanjwa phakathi luhlolo.