I izinduku kanye Izigaxa. Izigaxa ngwengwzi. Isakhiwo retina - isikimu

Vision - kungenye yezindlela ukuzwa ngezwe futhi eMpumalanga ngokwabo emkhathini. Naphezu kweqiniso lokuthi izinzwa nayo ibalulekile kakhulu, ngosizo iso womuntu kuthatha cishe u-90% lonke ulwazi ivela imvelo. With ikhono ukuze ubone ukuthi yini esizungezile, kufanele sitshele ngezenzakalo, ukuhlukanisa izinto komunye nomunye, futhi itjheje izinsongo. emehlweni abantu ahlelwe ukuze ngaphezu lezinto ngokwazo Basaba ukuhlukanisa nombala, okuyinto zaveza ezweni lethu. Lubhekele lolu ekhethekile amaseli ezincane - izinduku kanye Izigaxa abakhona e-retina kumuntu ngamunye kithi. Siyabonga kubo kwasenza saqonda ifomu kolwazi ambient idluliselwa kuya ebuchosheni.

Isakhiwo umdwebo iso

Naphezu kweqiniso lokuthi iso kuthatha isikhala okuncane kakhulu, kuyishwa nje yakhiwa sebuningini izakhiwo yokwakheka, sibonga ngalo siyakwazi ukubona. Isitho obonayo cishe ngqo ezixhumene nobuchopho, futhi ngosizo isifundo bamehlo ekhethekile ukubona empambana emsipheni optic. I inhlamvu yeso has simise eyindilinga futhi itholakala endaweni ekhethekile ikhefu - orbit, ezakhiwe amathambo skull okuyinto. Ukuze uqonde ukuthi yini edingekayo umzimba eziningi isakhiwo, kubalulekile ukwazi isakhiwo iso. Isifanekiso ebonisa ukuthi iso kuhlanganisa nezinhlangano ezifana le Vitreous, lens, anterior kanye posterior amakamelo emsipheni optic futhi igobolondo. Ngaphandle kwe-umzimba ihlanganisa sclera - zokuzivikela igobolondo amehlo.

igobolondo amehlo

I sclera inomsebenzi ukuvikela inhlamvu yeso ekulimaleni. Kuyinto udonga lwangaphandle futhi uphethe mayelana 5/6 of ebusweni nomzimba. Ingxenye sclera, okuyinto ngaphandle futhi kwemvelo kudlulela ngqo, okuthiwa i-cornea. Ingabe izakhiwo esingokwemvelo ukuthi siyakwazi ukubona izwe ngokucacile. The main wabo - kukhona izinto obala, reflectivity, umswakama, olubushelelezi kanye nekhono kudlule bese refract imisebe. Okusele sejazi elingaphandle iso - the sclera - siqukethe obukhulu zezinzwa izicubu nohlaka. Ngezansi kuba ungqimba elilandelayo - semithambo. igobolondo Isilinganiso imelelwa izinhlangano ezintathu uchungechunge: iris, ciliary (ciliary) umzimba futhi horeoideya. Ngaphezu kwalokho, ungqimba semithambo kuhlanganisa umfundi. Limelela imbobo encane, engamboziwe iris. Ngayinye yalezi izinhlangano has lwenza umsebenzi walo ohlukile, okuyilona elidingekayo ukuze unikeze umbono. I last ungqimba - a-retina. Kuyinto ukuthintana ngqo nge ubuchopho. isakhiwo ngwengwzi luyindida kakhulu. Lokhu kungenxa yokuthi kubhekwa umzimba ebaluleke kakhulu igobolondo.

Isakhiwo retina

Inner emgodleni umzimba ziyingxenye ephambili we medulla. Yena imelelwa izingqimba sezinzwa, okuyinto ukhaphethi ingaphakathi iso. Ngenxa retina, sithola isithombe konke esizungezile. Yena igxile zonke imisebe refracted bese bedonseleka phezulu isihloko esicacile. Njengoba amangqamuzana ezinzwa e ukudlula e-retina phakathi optic yezinzwa ngawo Imininingwane bufike ebuchosheni. On ingaphakathi iso has endaweni encane, okuyinto esikhungweni futhi unawo amandla kakhulu umbono. Le ngxenye ibizwa ngokuthi i-macula. Le ndawo ezibukwayo amaseli - izinduku kanye Izigaxa amehlo. Zisinika imini nobusuku umbono wezwe.

Umsebenzi izinduku kanye Izigaxa

La mangqamuzana atholakala retina esweni futhi ayadingeka ukuze ubone. Izinduku kanye Izigaxa kukhona transducers omnyama umbono ezimhlophe nombala. Zombili lezi zinhlobo zezindlu lamaseli avele iso ka-receptor photosensitive. Izigaxa kuthiwa ibizwa kanjalo ngoba ezakheke oyindilinga, zingabantu ukuhlobana phakathi kwe-retina kanye isimiso sezinzwa esiyinhloko. Umsebenzi wawo main - emizweni ukuguqulwa ukukhanya etholakala imvelo ibe amaza kagesi (pulses) okwenziwa ubuchopho. I ngokucacile yokuqaphela emini fanele Izigaxa ngoba ziqukethe sombala - iodopsin. Le into has a izinhlobo ezimbalwa amaseli azibonayo ingxenye ehlukile bohlu. Izinduku nozwela ukukhanya, ngakho-ke umsebenzi wabo oyinhloko nzima - ukuqinisekisa ukubonakala lapho kuhlwa. Baphinde ziqukethe sombala - ikhemikhali rhodopsin ukuthi bleached nge kwelanga.

Isakhiwo izinduku kanye Izigaxa

Igama la mangqamuzana wathola ngenxa ezakheke - cylindrical futhi oyindilinga. Ngezinduku ngokungafani Izigaxa, elise ngaphezulu azungeze retina futhi cishe ngingekho e-macula. Lokhu kungenxa umsebenzi wabo - ukuhlinzeka embonweni wasebusuku namasimu neuropathy ezibukwayo. Zombili lezi zinhlobo zezindlu iseli babe isakhiwo efanayo futhi libe izingxenye ezine:

1. ingxenye engaphandle - kuba eyinhloko sombala izinduku noma Izigaxa embozwe igobolondo. Rhodopsin futhi iodopsin kukhona izigubhu ezikhethekile - akwazi ukugcina.
2. Cilium - ingxenye yeseli, esinikela interconnection phakathi kumasegimenti yangaphandle futhi kwangaphakathi.
3. Mitochondria - bona ukuthi zibalulekile ukuze kube amandla umzimba. Ngaphezu kwalokho, ukuthi akuphi EPS kanye enzyme ezidingekile synthesis izingxenye yeselula. Konke lokhu kungenxa ingxenye engaphakathi.
4. eziyimpumelelo Nerve.

Inani receptor ukukhanya-sensitive kwe-retina siyahluka kakhulu. amaseli Rod- ezakha yizigidi ezingu-130. Izigaxa retina lungaphezu kunabayeni nabo inombolo, ngokwesilinganiso, kunezindlela abangaba yizigidi ezingu-7.

Izici adlulisele ukukhanya pulses

Izinduku kanye Izigaxa bayakwazi ukubona okukhipha ukukhanya ayidlulisele isimiso sezinzwa esiyinhloko. Zombili lezi zinhlobo zezindlu lamaseli bayakwazi ukusebenza ngesikhathi sasemini. Umehluko wukuthi nozwela Izigaxa iphakeme kakhulu kunanoma izinti. amasignali Transmission yamukelwa ngokusebenzisa interneurons, ngamunye ohlanganyela receptor eziningana. Association of amaseli eziningana induku emise ukwenza isitho nokuzwela umbono likhulu kakhulu. Lesi senzakalo ngokuthi "Kuhlangana" ezaziwayo. It usinikeza umqondo wayo eziningana Amasimu ezibukwayo, kanye nekhono wasithatha ukunyakaza ahlukahlukene eyenzekayo emhlabeni.

Nekhono lokuqonda imibala

Bobabili izinhlobo receptor ngwengwzi ayadingeka hhayi kuphela ukuhlukanisa phakathi kosuku embonweni wasebusuku, kodwa futhi ukucacisa izithombe umbala. Isakhiwo Iso lomuntu evumela izinto eziningi: ukuthatha indawo enkulu nokuvikelwa kwemvelo, ukubona nganoma isiphi isikhathi sosuku. Ngaphezu kwalokho, siba omunye amakhono ezithakazelisayo kakhulu - umbono Binocular, okuvumela ukunweba Ukubuyekeza kakhulu. Izinduku kanye Izigaxa zinengxenye bezibona ephelele cishe zakho konke bohlu umbala, ukuze abantu ngokungafani nezilwane, ukuhlukanisa yonke imibala zomhlaba. umbono Color ukunikeza degree Izigaxa enkulu okuyizinto 3 izinhlobo (emifishane kanye nephakathi nendawo wavelength eside). Nokho, izinti futhi babe nekhono lokuqonda ingxenye encane bohlu.