SISTEMAI KhUNGARD

SISTEMAI KhUNGARD, sistemai khunkashoi, majmui ragho va kovokiho (javfho)-i organizmi hayvon va odam, ki dar onho khun yo gemolimfa megardad. Sistemai khungard organizmro bo moddahoi gizoi va oksigen tamin mekunad va mahsuloti mubodilai moddahoro khorij menamoyad. Sistemai khungard du nav meshavad: sarbasta va gayrisarbasta (lakunari). Sistemai khungardii sarbasta baroi baze hayvonhoi bemuhra (masalan, halqakirmho), hamai hayvonhoi muhrador va odam, Sistemai khungardi gayrisarbasta boshad, ba aksari hayvonhoi bemuhra (bandpoyho, narmbadanho) va hayvonhoi khordadori darajai past khos ast. Dar hayvonhoe, ki Sistemai khungardashon gayrisarbasta ast, mubodilai moddaho bayni khunu boftaho bevosita dar khudi boftaho ba amal meoyad. Dar hayvonhoe, ki Sistemai khungardashon sarbasta ast, mubodilai moddaho dar bayni khunu boftaho ba vositai devorai ragho ba vujud me- oyad. Sistemai khungardi az hama soddatarin Sistemai khungardi nemertinhost. Vay az 3 ragi tuloni (ragi takhtapusht va du ragi pahlui) iborat ast. Az hama murakkab Sistemai khungardii hayvonhoi muhrador va odam meboshad.

  Vobasta ba tarzi nafaskashi (bo galsama yo shush) dar hayvonhoi muhrador khun dar yak yo du davr gardish mekunad. Hayvonhoi muhradore, ki bo galsama nafas mekashand, yak davri gardishi khun va hayvonhoi muhradori khushkigardu odam, ki bo shush nafas mekashand, du davri gardishi khun (davri khurd va davri kalon) dorand (Nigared niz Gardishi khun). Dar odam, hayvonhoi muhrador va baze hayvonhoi bemuhra (masalan, narmbadanho) uzvi asosii Sistemai khungard dil ast. Raghoe, ki khunro aa dil ba boftaho va uzvhoi badan mebarand, arteriya (sharayon yo surkhrag) va raghoe, ki khunro ba dil meorand, vena (varid ë siyohrag) nomida meshavand. Devorai arteriyaho az se qabat iborat ast: daruni, miyona va beruni. Dar arteriyahoi kalon boftahoi chandir va dar arteriyahoi miyona va khurd az hujayrahoi mushaki bisyorand. Arteriyaho ba shokhaho, shokhchaho va shokhchahoi maydatarin taqsim meshavand. Hamai onho bo hamdigar payvastand. Arteriyahoi az hama mayda arteriolaho buda, ba kapillyarho (muragho) tabdil meyoband. Devori kapillyarho az yak qabat hujayrai epiteli iborat buda, ba guzaronidani moddahoi gizoi va gazho muvofiq ast, kapillyarho bo hamdigar vasl shuda, shabakai (turi) kapillyari hosil mskunand. Az onho raghoi badikapillyari, soni venachahoi mayda va minbad venaho hosil meshavand. Devorai venaho khele tunuk va qabati mushakii onho zaif ast. Binobar in devorahoi venahoi kholi ba yakdigar mechaspand. Harakati khun dar venaho ba faoliyati dil, quvvai kashishi qafasi sina, kashishkhurii mushakhoi devorai venaho vobasta ast. Dargothoi andaruni venaho ba jarayoni aqibnokii khun mone meshavand. Khuni korkardashuda (murdor) bo venai tihii poyoni ba dil (peshdili rost) merezad.

N. U. Usmonov.