Isikhonkwane
Isikhonkwane yinto eyinkcenkce enentloko esibaca kunye nomphambili wayo omde nocwejileyo. Isando okanye isibetheleli sikhonkwane sisetyenziswa ngokubekwa kwenye into. sisoloko sisetyenziswa ukudibanisa izinto ezimbini.
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[tshintsha | Yenza izilungiso kokubhaliweyo]Isikhonkwane sisakhiwo esicacileyo semi-transparent apho iziphelo zeminwe yezilwanyana ezininzi, ngokubanzi ziyingxenye yeklasi ye - tetrapods, kuquka nabantu, isiphelo. Izikhonkwane zibonisa iindidi ezirhubuluzayo, iintaka kunye nezilwanyana ezanyisayo ; Ulwakhiwo lwazo luye lwavela kwi-phylogenetically ukususela kwizilwanyana ezirhubuluzayo, ngaphandle kwe -pipid amphibians eziye zavela kwizakhiwo ezizimeleyo ngokuzimeleyo. [1]
Izikhonkwane zinomsebenzi wokuququzelela ukubamba, ukufaka isandla ekuzinzeni kwesakhiwo seminwe kunye nokunciphisa ukugqoka iziphelo ezidibana nomhlaba. Iintlobo ezahlukeneyo zezikhonkwane zinamagama ahlukeneyo ngokuxhomekeke kwiingcali ezisebenzayo, ezifana neenzipho okanye iimpuphu: i-claw inambuzane echazwe kwi-tarsomere yokugqibela, nokuba imvelaphi eyahlukileyo ngokupheleleyo, ibizwa ngokuba yi-nail ngenxa yobudlelwane obusebenzayo, kwaye iqulunqwe ngokukodwa. ukusuka kwi -chitin .
Izikhonkwane ngokuyinhloko zenziwe ngamacandelo amaninzi e-keratin. Elona candelo lingaphandle kwaye linzima yi unguis, eyenziwe yimicu ethe ngqo kwicala lokukhula. Inxalenye engaphantsi ayinzima kakhulu kwaye inesakhiwo se-lamellar. Izikhonkwane zenkawu kunye nezinye izilwanyana ezininzi zenziwe kuphela ngu-unguis (eswele isikhonkwane esincinci), ngelixa amanye amaqela, afana ne -cebids ezininzi, enezinzipho.
- ↑ "LE UNGHIE, SPIE DEL BENESSERE" 20 febbraio 1997