Mubodilai gazho dar shush va boftaho

Harakathoi nafasgiri. Nafas giriftan va nafas barovardan yakdigarro mavzun ivaz karda, ba vositai shush guzashtani havo va avotozakunii shushro tamin mesozand.  Ivazshavii nafasgiri va nafasbaroriro markazi nafasgiri tanzim mekunad, ki on dar magzi darozruya joygir ast. Dar markazi nafasgiri impulsho muntazam ba amal omada, tavassuti asabho ba mushakhoi bayni qaburgagi va diafragma doda meshavand.

Dar natija mushakho kashish khurda, qaburgaho bolo meshavand, diafragma qarib hamvor megardad. Kovokii qafasi sina vase megardad. Dar natija nafasgiri ba amal meoyad. Bad mushakhoi bayni qaburgahoyu diafragma sust shuda, hajmi kovokii qafasi sina khurd megardad va az shushi fishurdashuda havo berun mebaroyad. Dar in hol nafasbarori ba amal meoyad.

Odami kalonsol dar holati nisbatan orom dar yak daqiqa takhminan 12-16 marotiba nafas megirad. Dar khonae, ki havoyash toza nashudaast, harakathoi nafasgiri duchand va az in ham beshtar meshavand. In az on sabab ruy medihad, ki hujayrahoi asabi markazi nafasgiri gazi karbonati tarkibi khunro his mekunand. Hangomi ziyod shudani miqdori on angezishi nafasgiri avj girifta, impulsho tavassuti asabho ba mushakhoi nafasgiri pahn meshavand. Dar natija odam tez-tez va chuqur nafas megirad. Hamin tavr nafasgiri bo rohi asabi va humorali tanzim karda meshavad.

Hajmi hayotii shush. Hangomi orom nafasgiri ba shushi odami kalonsol qarib 500 sm3 havo dokhil meshavad. Dar vaqti orom nafas borovardan ham az uzvi nafasgiri hamin miqdor havo khorij meshavad.

Miqdori ziyodtarini havoe, ki odam badi nihoyat chuqur nafas giriftan mebarorad, taqriban ba 3500 sm3 barobar ast, ki onro hajmi hayotii shush menomand. Hajmi hayotii shushi odamoni gunogun har khel ast. Onro hangomi muoinai tibbi bo yorii asbobi makhsus – spirometr muayyan mekunand.

Mubodilai gazho dar shush. Miqdori gazho hangomi nafasgiri va nafasbarori yak khel nest. Dar havoi nafasgiri qarib 21% oksigen, nazdiki 79% nitrogen, taqriban 0,03% gazi karbonat, kame bugi ob va gazhoi inerti mavjudand.

Tarkibi havoe, ki mo khorij mekunem, digar ast. Dar on hamagi 16% oksigen boqi memonad, vale miqdori gazi karbonat to ba 4% meafzoyad, miqdori bugi ob niz ziyod meshavad. Faqat nitrogen va gazhoi inerti dar havoi khorijkardaamon ba hamon miqdore, ki dar havoi nafasgiriftaamon budand, boqi memonand.

 Miqdori gunoguni oksigen va gazi karbonat dar havoi nafasgiriftaamon va khorijkardaamon ba vositai mubodilai gazho dar hubobchahoi shush manidod karda meshavad. Miqdori gazi karbonat dar muyraghoi varidii hubobchahoi shush nazar ba havoi hubobchahoi shush khele ziyod ast. Gazi karbon az khuni varidi ba hubobchahoi shush dokhil shuda, dar vaqti nafasbarori  az organizm khorij meshavad. Oksigen az hubobchahoi shush ba khun dokhil shuda, bo gemoglobin bo rohi kimiyovi payvast meshavad.

 Dar natija khuni varidi ba khuni sharyoni mubaddal megardad. Khuni sharyoni tavassuti raghoi varidi shush avval ba dahlezi chapi dil, bad ba medachai chap va nihoyat ba davri kaloni gardishi khun dokhil meshavad.

 Mubodilai gaz dar bofta. Oksigen az muyraghoi davri kaloni gardishi khun ba boftaho dokhil meshavad (rasmi 60). Dar khuni sharyoni nisbatan hujayrahoi ba oksigen ehtiyojmand ziyod ast. Az hamin sabab onho ba osoni mavqe yofta, dar ravandi oksidshavi ishtirok mekunand. Gazi karbonat boshad, az hujayraho ba khun medaroyad. Hamin tavr boftahoi uzvhoi khuni sharyoni ba khuni varidi mubaddal meshavand.

 Khuni varidi bo raghoi varidi davri kaloni gardishi khun ba dahlezi rosti dil dokhil shuda, bad ba medachai rost va az on jo ba shush meravad.

 Savolho

1. Hamohangii nafasgiri chi tavr tamin megardad?
2. Nafasgiri va nafasbarori chi khel ba amal meoyad?
3. Hajmi hayotii shush chist?
4. Mubodilai gazho dar shush chi khel ba amal meoyad?
5. Mubodilai gazho dar boftaho chi khel ba amal meoyad?

Kori amali

Chen kardani gunjoishi hayotii shush Tajhizot baroi amaliyot: spirometri namnok yo khushk, pakhta, spirt.

Rafti amaliyot:

a) Spirometrro ba dahon guzoshta dar holati oromi nafas

barored va miqdori havoro muayyan kuned.

b) Bad chuqur nafas barovarda, havoi berunshudaro chen kuned.

v) Chuqur nafas girifta nafas barored va in havoro ham chen kuned.

g) Hamai miqdori havoro ba ham jam kuned va gunjoishi hayoti shushro muayyan sozed.