CO the.
Hoqt ddng cua GV - GV neu cau hdi:
Khi lao dpng nang, lugng CO2 san sinh nhidu thi hipn tugng gi se xay ra?
- GV danh gia va bd sung kien thiie.
+ Ndng dp CO2 tang se giam pH do.
C02 + HjO -^ H2CO3 ^ H* + HCO"3
He dem HCOr se lam
Hoat dpng cua HS
- HS thao luan, van dung
ki^n thlie d phie'u hoc tap sd2.
- HS neu duge:
+ CO2 sinh ra nhidu dugc didu chinh bing he dpm bicacbonat.
+ Khi lao dpng nang nhip thd tang dd thai CO2 ra ngoai.
- Dai dien nhdm tta Idi, ldp bd sung.
Ndi dung
Hoqt dpng cua GV Hoqt dpng cua HS Npi dung
giam tinh axit cua mau bing phan ling.
HCO, + H * ^ H 2 C 0 3 ^ CO2 + H2O + H* dugc hinh thanh se kich thich ttung khu h6 hap tang cudng th6ng khi phdi dd thai nhanh CO2 ra ngoai qua phdi.
+ GiQ thang bing dp toan, kidm.
- GV neu mdt sd eau hdi. + Khi lao dpng nang co thd cd nhiing phuang thdc toa nhiet nao?
+ Vi sao miia he da ngudi thudng hdng hio eon mila d6ng, nhit la khi trdi ret da thudng tai hoac sdn gai de? - GV yeu ciu HS: nit ra ke't luan vd su can bing nhiet ttong co thd.
* Cung ed: GV yeu ciu HS van dung kie'n thiic ciia bai khii quat hoa phan tieh vi du didn hinh dua tren co sd hinh 20 SGK ttang 83.
- HS cd thd hoi: khi lao dpng d noi mdi trudng cd ndng dp khi CO2 cao thi didu hoa bang each nao?
- HS van dung kie'n thiie sinh hgc 8 dd tta Idi.
+ Khi lao ddng nang eo thd thudng toat md h6i.
+ Miia he da hdng hao do mach dudi da dan ra. + Mua ddnjg da tai do mach CO rut mau vao ttong. - HS khai quat kie'n thiic. - HS cd thd van dung phan tich can bang ndng dp CO2 hay glucC trong mau.
3. Cdn bing nhiet
- Co che' can bing nhiet. + can bing giua qua ttinh sinh nhiet va toa nhipt dd than nhiet dn dinh.
+ Didu hoa bing eo che thin kinh va thd dich. * Ket luan chung: HS doc ke't luan cud'i bai trang 83 SGK.
IV. KIEM TRA DANH GIA
HS ttinh bay kie'n thiic trong tam ciia bai hgc. (adsbygoogle = window.adsbygoogle || []).push({});
V. DAN DO
- Hgc bai va tra Idi cau hdi SGK trang 83. - Chuin bi thuc hanh: ech hay cdc.
Bai 21.Th\ic hanh:
TIM HIEU HOAT DONG cCiA TIM ECH
I. MUC TIEU
- Quan sat dugc cac hoat dpng cua tim ech.
- Neu ro dugc su didu boa boat dpng ciia tim bing thin kinh va thd dich. - Trinh bay dugc su van chuydn mau trong dpng mach, tmh mach va mao
mach.'
- Ren luypn ki nang quan sit va thi nghipm, n^ng cad duoc y thiic ki luat, trat tu, ngan nap, ve sinh trong hgc tap.
II. CHUAN Bj
- GV hudng din nhdm yeu khoa hgc lam thi nghipm trudc va ghi chep kdt qua,
- Min: mdi nhdm ( 5 ^ 6 HS) chuin bi 1 con e'ch hay 1 con cdc. - Dung cu:
+ Hpp dung cu md. + Bang gd cd khoet 16.
+ Hp thdng ciu ghi va he thdng kich thich, kep tim va chi. - Hoa chit:
+ Dung dich sinh li (NaCl 0,65%). + Dung dich actrenalin 1/100000. + Nudc ngam thudc la hay thud'c lao.