Cau 11 : trinh bay qua trinh van chuyen oxi va UDLS cua qua trinh nay ?

- oxi dc vc trong mau d]oi 2 dang la dang hoa tan va dang ket hop

- dang hoa tan chiem khoang 3% ; 0,03ml/100ml nhung rat quan trong do tac dung truc tiep voi to chuc

HbO2?- dang ket hop chiem 97% O2 + Hb

1g Hb gan 1,34ml O2

14 - 16g Hb vc xap xi 20mlO2/100ml mau

Lk long leo de tach (pu phu thuoc vao phan ap O2, phan ap O2 cao <o phoi> xay ra theo chieu thuan va ngc lai)

Thi nghiem nghien cuu ve su vc O2

- Do thi VC O2:

Barcroft: cho mau toan phan ( chong dong) o ong nghiem khac nhau tiep xuc voi O2 o cac phan ap khac nhau

+) do thi -> noi len su bien thien ve ty le % HbO2 so voi tong lg Hb trong mau va o cac phan ap # nhau: ( ve do thi)

PO2 tu 20 - 40 do thi doc nhat

PO2 cang giam thi dt cang doc

+) 80 - 100 thi dt doc it nhat -> thay doi ko dang ke, ply HbO2 giam ko dang ke, van chiem 96 - 98% -> do thi bien thien qtrinh vc O2 co hinh chu S

1 Hb co 4 nhan hem, 1 hem ket hop voi O2 -> thay doi aI luc cua hem con lai -> bien dang do thi hinh chu S

Borh lam thi nghiem tren nen Tn cua barcroft: cho mau txuc voi PO2 # nhau dong thoi dat nhung caI binh do vao trong moI trg co phan ap CO2 # nhau ( ve do thi)

- tai noI PCO2 tang dt co xu huong chuyen phaI -> tang phan ly HbO2

- tao noI PCO2 thap -> kha nag ply HbO2 giam

Thi nghiem: datmu vao moI truong khac nhau, pH, nhiet do, nong do 2 - 3 DPG

o noI moI truong pH nghieng ve acid, nhiet do tang cao, sp 2 -3 DPG tang thi tye le % HbO2 giam ( tang qtrinh ply) tai mo qtrinh chuyen hoa tang -> nhiet do tang, noI chuyen hoa vc lon -> CO2 sinh ra nhieu -> pH giam, cung tai noI chuyen hoa nhieu sp 2 - 3 DPG-> mo, cquan chuyen hoa pH giam, nhiet do tang, sp 2 - 3 DPG tang

*) qua trinh vc O2 cua mau

o 2 noi:

- Nhan O2 o phoi (tdoi giua mau va phe nang) phu thuoc vao 2 yeu to

+ chenh lech giua mau va phe nang

+ tac dung borh ( of PO2)

Khi mau tinh mach dI qua phoi, do chenh lech phan ap, O2 tu phe nang khuyech tan vao huyet tg duoi dang hoa tan, PO2 trong huyet tg nhanh chong tang len = PO2 trong phe nang. Cung do su chenh lech ve phan ap O2 lai tu huyet tg khuyech tan va HC duoi dang hoa tan, lam cho PO2 o HC cung tanbg len sap xi trg phe nang. Voi phan ap 100mmHg, ty le HbO2 tang toi 95% muc b•o hoa, chua khoang 20ml O2/ 100ml mau va tro thanh mau DM

Khi mau DM toi cac mo, oxi hoa tan trg huyet tg khuyech tan vao dich ke TB lam cho PO2 nhanh chong ha thap xuong xap xi trg dich ke, O2 tu HC khuyech tan vao trong huyet tg , PO2 trong HC giam xuong. Tai mo PO2 giam ( khoang 40mmHg) -> tang ply HbO2, dong thoi PCO2 lon( 40mmHg), HbO2 cang bii phay ly. Mau chi con khoang 15mlO2/100ml mau.

- o ngung co dang van dong, co2 sinh ra nhieu hon luc nghi lam, ph cua mau nga ve acid, 2,3 DPG cao, nhiet do tai cho tang len -> muc do ply HbO2 cang cao, hieu suat sd O2 tang cao co the dat toc do 100% tuc la mau o tinh mach hau nhu ko con O2 nua. ngoai ra khi co dang va dong con cpo htg gi•n mach, tang luu lg mau den co lam lg O2 cung cap cho co tang cao , phu hop voi nhu cau cao ve O2 cua co dang vd