I-Retina: imisebenzi kanye nesakhiwo. Imisebenzi ye-retina

Ikhono lokusula nokucacisa umbono isici esiyingqayizivele hhayi nje kuphela ngabantu, kodwa futhi nesilwane. Ngombono wombono, kukhona ukuma endaweni emkhathini kanye nemvelo, ukuthola ulwazi oluningi: kuyaziwa ukuthi ngosizo leso, umuntu uphakamisela ku-90% wohlu lonke ulwazi mayelana nezinto kanye nemvelo. Isakhiwo esiyingqayizivele nokwakhiwa kwamaselula kuvumela i-retina ukuba ingaboni nje kuphela imithombo yokuvuselela ukukhanya, kodwa futhi ukuhlukanisa izici zabo ezibukwayo. Ake sihlaziye ukuthi i-retina isebenza kanjani, kanye nezici zenhlangano yayo ye-neuronal. Kodwa kuphela ukukhuluma ngesakhiwo salo ngeke kube ngombono womuntu ophethe umthwalo wolwazi lwesayensi, kodwa kusukela ekubukeni kwesakhamuzi esijwayelekile.

Imisebenzi ye-retina

Ake siqale ngamaphuzu avelele. Impendulo yombuzo wokuthi yimiphi imisebenzi eyisisekelo ye-retina, ilula kakhulu. Okokuqala, lo mbono wokuvuselela ukukhanya.

Ngokwemvelo yayo, ukukhanya yi-wave electromagnetic ngevolumu ethile ye-oscillation, okubangela umbono we-retina ngemibala ehlukahlukene. Ikhono lokubala umbala liyingxenye eyingqayizivele yokuziphendukela kwezilwane ezincelisayo. Ngosizo lwempumelelo yesayensi, imishini yesimanje, izinhlanganisela zamakhemikhali amasha, kwakungenzeka ukuthi zibheke ngokujulile kwisakhiwo sezitho zombono, ukucacisa izinqubo ze-biochemical nokuqonda kangcono ukuthi i-retina isebenza kanjani. Futhi, njengoba kuvela, okuningi, futhi ngamunye uhlukile.

I-Retina yeso: isakhiwo nomsebenzi

Abaningi bayazi ukuthi i-retina ikhona ngaphakathi kweso futhi ingumlenze wayo wangaphakathi. Kuyaziwa ukuthi ekubunjweni kwalo kuqukethe amangqamuzana okuthiwa ama-photosensitive cells. Ngaso leso sikhathi sibonga kubo futhi wenza umsebenzi we-retina we-photoreception.

Amagama abo avela ekujuleni kwamaseli. Ngakho-ke, amangqamuzana afana nensimbi ayebizwa ngokuthi "izinduku", namaseli, afana nomkhumbi wamakhemikhali okuthiwa "i-flask" - wathola igama elithi "ama-cones".

Izinti kanye nama-cones ahluke kuphela ezinkambisweni zabo ze-histological. Umehluko omkhulu phakathi kwabo yindlela ababona ngayo ukukhanya kanye nezici zayo ezibukwayo. Izintambo zibophezele ekuboneni ukukhanya okukhanyayo ngesikhathi sokusabalala - ncamashi lapho, njengoba bethi, "wonke amakati aphezulu." Kodwa ama-cones anesizathu sokubona umbono wombala.

Izici ezisebenzayo zama-cones

Phakathi kwama-cones, kunezigaba ezintathu ezihlukene: izigaxa ezibhekene nokubona izingxenye eziluhlaza, ezibomvu neziluhlaza okwesibhakabhaka, ngokulandelana. Isigaxa ngasinye sinomthelela ekwakheni umbala wombala, ukucubungula isithombe esenzelwe i-lens. Emidwebeni, ukwakheka kombala wokugcina kuncike ekulinganiseni lapho umdwebi athatha khona upende. Ngokufanayo, i-retina idlulisa ulwazi mayelana nesici sokubukeka sokukhanya: kuye ngokuthi izimpondo ze-cone zikhishwa ngayinye yamaqembu, sinombono wombala othile.

Isibonelo, uma sibona umbala oluhlaza, ama-cones aphethwe esifundeni esiluhlaza se-spectrum avuliwe kakhulu. Futhi uma sibona obomvu-ke, ngokulandelana, ngokubomvu. Ngakho-ke, imisebenzi ye-retina yeso lomuntu ayibona kuphela ekuboneni ukukhanya kokukhanya, kodwa futhi ekuhloleni okuyinhloko kwezici zayo ezibukwayo.

Izitha ze-retina, nokuthi kungani zidinga

Mhlawumbe othile ucabanga ukuthi ngemva nje kokuba i-lens ibonakale ngqo ezindongeni nama-cones, futhi sebevele baxhumane nezintambo ze-optic nerve futhi baphathe ulwazi ebuchosheni. Eqinisweni, lokhu akunjalo. Ngaphambi kokufinyelela izinti kanye nama-cones, ukukhanya kufanele kunqobe zonke izingxenye ze-retina (futhi kunezingu-10 zazo) futhi ngemva kwalesi senzo kumaseli afisa izithombe (izintambo nama-cones).

Ingqimba yangaphandle ye-retina yisendlalelo se-pigment. Umsebenzi walo ukuvimbela ukukhanya kokukhanya. Lolu hlobo lwamaseli we-pigment luhlobo lwekhamera yekhamera elimnyama lekhamera (okungukuthi, umbala omnyama awudala izici ezivelele, okusho ukuthi isithombe siyacaca kakhulu, ukukhanya kwesibani kuyanyamalala). Lolu ungqimba lunikeza ukwakheka kwesithombe esibukhali ngomsakazo optical iso. Ngokuseduze kocingo lwamaseli e-pigment, unamathele kanye nama-cones anamathele, futhi lesi sici senza sikwazi ukubona ngokucacile. Kuvela ukuthi izingxenye ze-retina zikhona njengokungathi emuva. Ingqimba elingaphakathi kungqimba lwamangqamuzana athile ahlanganisa ulwazi olungenayo kusuka ezintanjeni nama-cones ngamaseli asemkhatsini wesendlalelo esiphakathi. Ama-axoni alawa maseli aqoqwe ndawonye yonke indawo ye-retina futhi ashiye i-eyeball nge-okuthiwa i-blind spot.

Kule ndawo azikho izitifiketi nezithombe ezibonakalayo, futhi i-nertic optic iphuma ebusweni be-eye. Ngaphezu kwalokho, lapha ukuthi izitsha ezinikeza i-trophic ye-retina ingena. Isimo somzimba singabonakala esimweni sezitsha ze-retina, okuyindlela elula futhi ecacile yokuhlola izinhlobo ezahlukene zezifo.

Indawo yangaphakathi yezinduku nama-cones

Imvelo ikhulelwa ukuze izintambo nezigaxa zingabelwe ngokungafani kulo lonke ubuso be-retina. E-fovea ephakathi (isifunda sombono ongcono), ukuxilongwa okuphezulu kwezingqimba kubonakala. Lokhu kungenxa yokuthi le ndawo ibhekene nombono ocacile. Njengoba usuka enkabeni ye-fossa, inani lamaconsi liyancipha, futhi inani lezinduku landa. Ngakho-ke, i-periphery ye-retina iboniswa kuphela ngamathanga. Lesi sici sesakhiwo sinikeza umbono ocacile ezingeni eliphezulu lokukhanyisa futhi kusiza ukuhlukanisa izinkulumo zezinto eziphansi.

Inhlangano ye-Neuronal ye-retina

Ngemva kwezingqimba zezinduku nama-cones kukhona izingqimba ezimbili zamangqamuzana ezinzwa. Lezi yizingqimba ze-bipolar ne-ganglionic cells. Ngaphezu kwalokho, kunezingqimba zesithathu (eziphakathi) zamaseli angqimba. Inhloso eyinhloko yaleli qembu ukuphathwa okuyisisekelo kwezinto ezifakiwe, ezivela ezindongeni nama-cones.

Amaqiniso anentshisekelo mayelana nesakhiwo se-retina

Manje siyazi ukuthi i-retina iyini. Isakhiwo nemisebenzi yaso sekucatshangwe. Kubalulekile futhi ukukhuluma ngamaqiniso athakazelisayo kakhulu ahlobene nalesi sihloko.

Ukuze ufinyelele isendlalelo se-pigment, ukukhanya kufanele kudlule kuzo zonke izingqimba zamangqamuzana ezinzwa, ungene phakathi kwezinduku nama-cones uphinde ufinyelele isendlalelo se-pigment!

Esinye isici sokwakhiwa kwe-retina yinhlangano yokunikeza umbono ocacile emini. Okubalulekile ukuthi ngaphakathi kwe-fossa ngayinye i-cone ixhuma esitokisini sayo se-ganglionic, futhi njengoba idlulela endaweni ehamba phambili, iseli elilodwa le-ganglion liqoqa ulwazi kusuka ezintanjeni eziningana nama-cones.

Izifo zokubuyisa kanye nokuxilongwa kwazo

Ngakho yimuphi umsebenzi we-retina? Yiqiniso, lo mbono we-flux ukukhanya, okwenza isimo se-refractive iso. Ukuphulwa kwalo msebenzi kuholela ekuphukeni kombono ocacile. E-ophthalmology kunezinombolo eziningi zezifo ze-retina. Lezi yizifo ezibangelwa izinqubo eziguqukayo, nezifo ezisekelwe ezinkambweni ze-dystrophic and tumor, inqola, izinhlungu.

Izimpawu ezisemqoka neziphambili ezingakhuluma ngezifo ze-retina ziyinkinga yokubonakala okubonakalayo. Esikhathini esizayo, kungenzeka kube nemibuthano ye-optical, ukulahlekelwa kwezinkambu ezibukwayo nezinye izimpawu eziningi. Kufanele kukhunjulwe ukuthi ngokunciphisa ukubonakala okubonakalayo, i-ophthalmologist kufanele ibonane ngokushesha futhi ihlolwe.

Isiphetho

Ukubukeka - isipho esikhulu semvelo, kanye ne-retina, imisebenzi kanye nesakhiwo sayo - ehlelwe kahle njengento eyakhiwe futhi esebenzayo ye-eyeball.

Ukubonisana ngesikhathi nokuhlolwa okuvimbela ophthalmologist kuzosiza ukuthola izifo ze-analyzer ebonakalayo bese uqala ukwelashwa ngesikhathi. Ngenhlanhla, imithi yesimanje inebuchwepheshe obuyingqayizivele evumela ngokoqobo imizuzu engu-20-30 ukuqeda ukukhathazeka okubukwayo futhi kutholakale ikhono lokususa umbono. Futhi ukwazi ukuthi i-retina yenza umsebenzi, ungawubuyisela.