- Cac qui iuit van chuyen mau trong he mach Phan xa dieu hoa tim mach.
2. Hoat dpng cua hp mach
- Mau van chuyen trong hp mach:
+ Tuan theo cac qui luat vat li.
+ Lien quan chat che de'n ap suit diy mau.
+ Luu lugng mau chuydn va van tdc.
4- Siic can ciia mach.
a) Huye't dp
Hoqt ddng cua GV
- GV nhan xet va dinh gia
ket qua cua nhdm.
- GV yeu ciu HS khai quat ki^n thlie.
- GV bd sung kieh thiic: + Su gian din ciiabuyet ap trong qua trinh van chuydn mau la do ma sat vdi thanh mach va giGa cae phan lir mau vdi nhau.
+ Tdng dipn tich cua thanh cac mao mach va mau bi ma sat la 6300m^.
- GV neu cau hdi:
+ Tai sao d ngudi cao tudi hay bi huyet ap cao? + Tai sao d nhihig ngudi bi huyet ap cao khi bi xuit huyet nao ed thd din den tir vong hay bi bai lipt? +Huye't ap thip gay nen tac hai nhu th^ nao?
Hoqt dpng cua HS
+ Khai niem huyet ap. + Nguyen nhan gay huyet ap do tim co.
+ Huyet ap giam din tCt dpng mach->- mao mach. + Su thay ddi huy^t ap do mach vi miu.
- Dai dipn nhdm tta Idi -> ldp nhan xet.
- HS tdng hgp cac kiSh thiic vi ket luan
- HS thao luan nhdm sit dung cac kiin thiic vd huydt
ap va kie'n thiie thuc t^ dd tra Idi dugc:
+ Mach mau bi xo cung tinh din hdi kem, siic can tang (dac bipt la mach mau
Ndi dung
•
* Khdi niem huy^t dp:
_ Huyet ap la ap luc mau do tim CO tdng mau vao dpng mach chu, tao nen huye't ap dpng mach. - Huye't ap cue dai ung vdi lilc tim eo, huy^t ap cue tidu ling vdi liic tun dan;
- Tim dap nhanh, manh • •
lam tang huy^t ap. Tim dap cham, y^u lam huye't ap ha - Huye't ap cao nhit d dpng mach chu, giam manh qua mao mach va thip nhit d t'mh mach chu.
Hoqt dpng cua GV
* Lien he: bpnh huyet ap lien quan den che dp an va Uang thai tinh thin.
- Lam thd nao dd giam nguy CO mic bpnh huyet ap d ngudi?
- GV neu cau hdi:
+ van tdc mau thay ddi nhu the" nao ttong he mach? Su thay ddi dd do dau? Cd >' nghia gi?
Hoqt dpng cua HS nao) -^ gay tang huyfit ap.
+ Xuit huyet nao la hien tugng vd mach miu nao. + Mau se d6ng lai thanh cue d nao din deh tii vong, hoac mau ddng nhidu chen ep cac trung khu d nao dac bipt la ttung khu van dpng, gay bai lipt d nira ngudi phia ddi dien.
+ HuySt ap thip do tim dap ye'u, cham khdng cung cap du mau cho nao, dd bi choang vang, ngit.
- HS cd thd van dung hidu
biet thuc ti cm. ban than
hay gia dinh dd Ua Idi. Yeu ciu neu dugc:
+ Giam bdt pr6tein ttong khiu phin an.
+ Tang cudng an rau vi hoa qua.
+ An md thue vat.
+ Sdng thanh than, ttanh Stteet. * - HS nghien eihi SGK ttang 77 d^ tta Idi. Yeu ciu neu dugc:
+ van tdc mau Idn nhat d ddng mach va giam dSii d
Npi dung
b) Van tdc mdu
Hoqt dpng cua GV
- GV danh gia va giiip HS
hoan thipn kien thiic.
Hoqt dpng cua HS
mao mach.
+ Sir thay ddi la do ciu tao cua mach.
+ Didu nay cd y nghia vdi qua trinh trao ddi chit. - Ldp theo doi, nhan xet.
- HS din chiing bang cac sd lipu.
+ Tid't dipn cua ddng mach chu la: 5-6 cm^, van tdc mau: 600mm/s.
+ Tdng tiet dien mao mach la 6200 cm^ van tdc mau: 0,5mm/s.
Npi dung
Ke't luan:
- Van tdc mau phu thupc vao ti^t dipn mach va chenh Ipch huyet ap giiia cac doan mach.
- Tiet dien nhd chenh lech huye't ap Idn, mau chay nhanh vi ngugc lai.
- Mau chay nhanh nhit trong dpng mach va cham nhit trong mao mach.