Yini enquma wamehlo?

Njengoba izingane ifa wamehlo? Ingabe kunendlela ukubikezela lokho kuzoba ingane? Kungani ama-albino pink? Uma bobabili abazali nge brown amehlo, khona-ke ngabe benza azalwe, izinyane blue uneso? Kangakanani umbala iris? Le mibuzo ehambisana ngaso sonke isikhathi. Impendulo kubo eziqukethwe Imininingwane izici ngaphakathi nangaphandle umzimba kwakhiwa ngesisekelo genotype kanye labawatfolile esifundvweni nobe ukuthuthukiswa ngabanye. Kusho ukuthini lokhu, futhi yini enquma umbala iso womuntu?

Lesi sici kunqunywa lesikhumba iris (iris) eyakhiwa ectodermal (obulungisekayo) kanye mesodermal (phambili) izingqimba. Okungukuthi, umbala iso lesintu lincike ekuhlaleni ubunjalo fustsina ukusatshalaliswa (kuyasiza ukukhiqiza sombala ezibukwayo ubamba ukukhanya kuvimbela ukushabalalisa yayo kanye nekucabangisisa, okuholela nokucija ngcono yesithombe ezibukwayo) e sombala amaseli backsheet futhi melanin (zemvelo esimnyama) ku sombala-equkethe nokukhanya-obonisa amaseli (chromatophores) ngaphambili ungqimba. On the umbala futhi ehlaselwe isimo izitsha iris yemisipha, inombolo ezahlukene kanye nohlobo sombala, nakho inquma Genet. umbala Eye kubangelwa ufuzo. Kodwa akuwona wonke waqonda.

Melanin kungukuqiniseka anemibala, ke asithinti nje kuphela umbala amehlo, kodwa futhi izinwele isikhumba amathoni. Nokho, qala bona inquma umbala amehlo? Melanin equkethwe ungqimba mesodermal, lo mnyama iris, kanti elincane ke kwasakazwa the sombala amaseli ungqimba anterior iris, i-ukuxegiselwa kuba. Kube melanin ensundu black (noma eumelanin), yellow (noma pheomelanin). Ukuze uhlobo kanye nobungako yalolu ketshezi lwemvelo nokusakazwa kwayo oluhambisana izakhi zofuzo ezithile. Ngenxa yalokho, coloration iris kungenzeka blue, oluhlaza okwesibhakabhaka, grey, green, inhlaka, marsh UCarey ukuthi abamnyama. Ingane ngeke balizuze ifa ukufana nomzali kokuba izimpawu evelele (nsundu, ukukhanya ensundu green) futhi akazange uthole umbala amehlo umzali benezici esikhubazayo (blue noma mpunga).

Ngezinye amehlo aluhlaza ungqimba emuva ezinemibala eluhlaza okwesibhakabhaka ngenxa semithambo kwakhiwa collagen ethandele, ngaphambili ungqimba has a okuqukethwe ubuncane melanin. Blue zihluke olumhlophe kwabantu ephakeme blue imicu: ayanda ukuminyana, le esithe ukuba lula iris. Mpunga wamehlo kungenxa kwabantu mkhulu collagen. Ngaphambili ungqimba esincane melanin oluhlaza ngenxa blue Umbala ungqimba iris adjustable kuyinto inhomogeneously anemibala oluhlaza futhi ezihlukahlukene. Yini enquma umbala amehlo amber? I lipofuscin sombala kuqinisekisa umbala wabo iyunifomu. Nge ngokulinganisela okuqukethwe melanin e uma kubanda ulwelwesi olungaphandle ixhaphozi iso babe noma ziyadliwa. Brown kukhona lapho chromatophores aqukethe eningi melanin. Ukuze black libhekene wokuqukethwe lelisetulu lesi sakhi, olubamba ngokuphelele ukukhanya. Esikhathini albino yena engekho, futhi iris livela pink noma zibomvu ngenxa umbala kuveza imithambo yegazi.

Izinsana abe iris blue, kodwa kungase mnyama eminyakeni embalwa ezayo. Kungani lo nalokho inquma umbala amehlo wengane? Melanin emzimbeni ngesikhathi sokuzalwa umbungu athuthukile, ngoba kungadingeki kuze kube yileso sikhathi, UV Ukuvikelwa, okuyinto eyenziwa sombala omnyama. Inhloso Its main - ukuvimbela umonakalo emisebeni ezicutshini zomzimba. Ngemva kokuzalwa, uqala ukukhiqizwa kwe-melanin ngu namangqamuzana akhethekile (melanocytes). Ngakho-ke, umbala iso wengane kweqiniso ayikwazi ukucaciswa ngaphambili kuka eminyakeni emithathu, nakuba izinguquko ngezinye izikhathi kuze iminyaka 10-12. Abadala Futhi ungashintsha umbala iris bedle izidakamizwa noma ngenxa yokugula. Ngokwesibonelo, kukhona coloration aphuzi ngenxa ekuqongeleleni lipofuscin.

Ngokuvamile kucatshangwa ukuthi evelele brown amehlo, futhi luhlaza - esikhubazayo. Kodwa isayensi yanamuhla eye kungase kutholakale ukuthi akusiyo ngakho elula. I mnyama umbala, kulapho-ke obusa: Brown ku green, green kokuluhlaza okwesibhakabhaka. Kodwa ngaso sonke isikhathi kube ingane brown amehlo, uma iris kusuka umama nobaba ensundu. Ezinganeni, kungaba ezahlukene. Ngokuvamile lokhu kubangelwa ukuthuthukiswa okuyiphutha sombala ezokuthutha, ukuhlukumezeka wendawo, noma esibelethweni noma ngokushesha nje ngemva kokuzalwa, kanye isifo esidluliselwa ngofuzo.