Óńesh – bul tolyq tútiksheli, as pen suıyqtyqty asqazanǵa ótkizetin anatomııalyq múshe. Jutynǵan kezde óńesh qabyrǵalaryndaǵy bulshyqetter jıyrylady jáne ishilgen asty asqazan qýysyna qaraı ıteredi. Óńeshtiń shyryshty qabynda ornalasqan bezder shyrysh bóledi, ol arqyly, tamaqty jutý protsessin jeńildetý úshin  óńeshtiń ishki jaǵy ylǵalmen qamtamassyz etiledi.  Óńesh keńirdektiń artqy jaǵynda ornalasqan, eresek adamdardyń óńeshiniń uzyndyǵy 25-ge deıin bolady.