Комрон.инфо
Uzvi gardishi khun. Ahamiyati gardishi khun. Sistemai uzvi gardishi khuni odam dil va raghoi khungardro dar bar megirad. Dil hamchun uzvi markazi, chun nasos kor karda, kashish mekhurad va khunro ba vositai raghoi khungard ba tamomi sathi badan mebarad. Dil harakati doimii khunro tamin mekunad.
Dar holati az kor mondani dil marg zud ba amal meoyad, zero mahz bo kashishkhurii dil khun ba hamai boftaho dokhil shuda, ba onho oksigen va moddahoi gizoi mebarad. Harakati khunro dar raghoi khungard gardishi khun menomand.
Sokhti dil. Dil dar qismi chapi kovokii qafasi sina joygir ast. Dili odam ba hisobi miyona 250- 300 g meboshad. Dil dar khaltai dil, ki az boftahoi payvastkunanda sokhta shudaast, joygir ast.
Haltai dil se vazifaro ijro mekunad:
1) doimo namnokii dilro nigoh medorad;
2) molishkhurii dilro az qaburgaho kam mekunad;
3) ba dil gizo medihad.
Dil az se qabat iborat ast: qabati berunii pushonanda, qabati mobaynii mushaki, qabati daruni. Dili odam ba monandi dili hayvonhoi shirkhur ba chor qism taqsim meshavad: dahlezi rost, dahlezi chap, medachai rost, medachai chap.
Qabati devorhoi dahlezho nazar ba medachaho tunuktar meboshad. Hun avval ba dahlezho, badan ba medachaho dokhil megardad. Medachaho kori khele muhimro ijro mekunand. Onho
kashish khurda, khunro ba raghoi khungard tela medihand. Devori mushaki medachai chapi dil nazar ba medachai rosti dil gafstar ast. Dar sarhadi bayni dahlezho ba medachaho darichahoi (klapanho) sedara va dudara mavjud buda, dar bayni medachai rost ragi sharyoni ba shush ravanda va dar bayni medachai chap shohrag darichahoi hilolshakl mavjudand.
Vazifai asosii darichaho (klapanho) ba yak samt ravona kardani khun meboshad. Hangomi kashishkhurii dahlezhoi dil darichaho ba tarafi medachaho kushoda shuda, khun ba medachaho merezad. Dar vaqti kashishkhurii medachaho darichaho mahkam meshavand va nameguzorand, ki khun ba dahlezho bargardad.
Raghoi khungard. Raghoi khungard ba tamomi badani mo pahn shudaand. Sokht, shakl, hajm va darozii raghoi khungard gunogunand (rasmi 45). CHor namudi raghoi khungardro farq kardan mumkin ast: shohrag, ragi sharyon, muyrag, ragi varid. SHohrag ragi kalontarin va kutohtarin ba hisob meravad. SHohrag va raghoi sharyon raghoe meboshand, ki ba vositai onho khun az dil harakat mekunad. Onho devorhoi mustahkam va chandir dorand, ki tarkibashon az mushakhoi sufta sokhta shudaand .
Dil kashish khurda fishori balandi khunro ba shohrag va raghoi sharyon tela medihad. Raghoi sharyon ba tufayli mustahkamu chandir budani devorhoyashon ba in fishor tobovarand va khurdu kalon meshavand. Raghoi sharyoni kalon ba qadri az dil dur shudanashon ba ragchahoi sharyon (arteriolaho) taqsim meshavand.
Ragchahoi sharyon boshand, ba muyragho (kapillyarho) mubaddal megardand, ki onho devori tunuk doshta, az yak qabat hujayrahoi epitelii nozuk tarkib yoftaand (rasmi 46). Onho imkon medihand, ki moddahoi dar plazmahoi khun halshuda az surokhii devori muyragho ba moei bofta va az onjo ba hujayra guzarand. Mahsuli faoliyati hayotii hujayraho az moei bofta ba vositai devori muyragho ba khun meguzarad. Organizmi odam
takhminan 150 mlrd. muyrag dorad.
Agar muyraghoro bo ham payvast kunem, bo onho girdi ekvatori kurai zaminro 2,5 marotiba pechonidan mumkin ast. Hun dar raghoi varid – raghoe, ki tavassuti onho khun ba dil meravad, jam meshavad. Fishori khun dar raghoi varid baland nest, devori onho nazar ba raghoi sharyon tunuktarand. Farq dar on ast, ki dar dokhili devori raghoi varid muyakchaho va klapanho mavjudand va onho ba yak taraf harakat kardani khunro tamin
menamoyand.
Hun dar organizm bo du sistemai sarbastai ragho harakat mekunad: 1) sistemai kaloni gardishi khun; 2) sistemai khurdi gardishi khun. Davri khurdi gardishi khun. Hangomi ba dahlezi rosti dil dokhil shudani khuni kamoksigen, medachai rosti dil kashish khurda, khunro ba ragi sharyoni tela medihad. Ragi sharyoni ba 2-shokha taqsim shuda, ham ba shushi rost va ham ba shushi chap meravad. Dar shush raghoi sharyon ba ragchahoi sharyon va muyragho tabdil meyoband va hubobchahoi havo shushro pechonida megirand.
Vaqte ki az muyraghoi shush khun jori meshavand, ba on oksigen dokhil megardad. Dar barobari in gazi karbonat, ki shush az on pur shudaast, az khun ba havoi shush meguzarad, yane dar muyraghoi shush khuni varidi ba khuni sharyoni tabdil meyobad. Bad khun dar muyragho jam meshavad. Onho bo hamdigar yak shuda, chor ragi varidi shushro tashkil mekunand, ki ba dahlezi chapi dil dokhil meshavand. Hamin tavr, gardishi khurdi khun az medachai rosti dil sar shuda, to ba shush rafta bad dar dahlezi chapi dil ba okhir merasad.
Davri kaloni gardishi khun. Hangomi kashish khurdan medachai chapi dil khunro ba vositai shohrag ba ragi sharyoni kalontarini badan mefiristad. Az on raghoi sharyon judo shuda, tamomi uzvho, az jumla dilro bo khun tamin menamoyand. Dar har yak uzv raghoi sharyon ba shokhaho judo shuda, ba shabakai zichi ragchahoi sharyon va muyragho tabdil meyoband. Tavassuti muyragho davri kaloni gardishi khun ba tamomi boftahoi badan oksigen va moddahoi gizoi dokhil shuda, az hujayraho ba muyraghoi gazi karbonat meguzarad. Dar ayni hol, khuni raghoi sharyoni ba khuni varidi tabdil meyobad. Muyragho avvalan ba raghoi varidi khurd va sipas ba raghoi varidi nisbatan kalon payvast meshavand. Az onho tamomi khun dar du raghoi varidi kholii kalon jam megardad.
Raghoi varidi kholii bolo az saru gardan va dastho, raghoi varidi poyon boshand, az hamai uzvhoi boqimondai badan khunro ba dil mebarand. Hardu ragi varidi kholi ba dahlezi rosti dil dokhil meshavand. Hamin tavr, gardishi kaloni khun az medachai chapi dil sar shuda tamomi sathi badanro bo khun tamin namuda, dar dahlezi rosti dil ba okhir merasad. Vaqti harakati khun dar organizm chunin ast: khun bo davri kalon dar 20-30 soniya va bo
davri khurd dar 4-6 soniya harakat mekunad.
Savolho
1. Gardishi khun chist va chi ahamiyat dorad?
2. Dil kadom vazifaro ijro mekunad?
3. Dil chand daricha (klapan) dorad va onho dar kujoi dil joygirand?
4. Darichaho kadom vazifaro ijro mekunand?
5. Kadom khususiyatho baroi raghoi sharyon, varid va muyragho khos meboshand?
6. Tafovuti tarkibi khun dar gardishi khurd va kalon dar chist?
