Cau 1: trinh bay tinh chat sinh ly cua co tim va UDLS

Co tim co chuc nang co tu dong, ko theo y muon va co nhip nhang de thuc hien cnang bom mau. De hoan thanh cnang nay co tim co 4 dac tinh sinh ly:

*) Tinh hung phan:

- Tinh hung phan la knang dap ung voi kick thick cua tim, the hien = co tim phat sinh dien the hoat dong, dien the nay lam co co tim.

* Dac diem ve knang dap ung voi kthick cua co tim: co tim dap ung voi kick thick = co co nhu co van, nhung co dac tinh rieng la dap ung theo quy luat "tat ca or ko"

- Thi nghiem: kick thick 1 mang co tim ech bang dong dien cam ung co cuong do tang dan va ghi do thi co co

co tim ko dap ung(ko co)?+) Voi cuong do kick thick duoi nguong

co tim co co toi da?+) Voi cuong do lon hon or = nguong

Co tim dap ung theop quy luat " tat ca or ko"?

- giaI thich: co tim ctao la 1 hop bao, co cac cau dan truyen hung phan hoat dong cua co tim nhu la 1 dong nhat. Khi kick thick?giua cac Tb tat ca?toi cuong do toi nguong thi toan bo cac soi co tim hung phan cac soi co tim deu co. do vay co tim co la co toi da.

- tinh hung phan cua co tim khac co van: co van gom nhieu soi co rieng biet, giua cac TB co ko co cau dan truyen hung phan nen khi bi kick thick thi tuy theo cuong do kick thick manh hay yeu ma so soi co tham gia nhieu hay it. Khi cuong do kick thick tang dan thi so soi co tim bien do co co tang cho den khi toan bo cac?tham gia dap ung tang dan soi co tham gia dap ung thi co co manh nhat

* Dac diem ve dien the hoat dong cua co tim

- hien tuong keo dai dien the dinh o co tim dc goi la cao nguyen

- dien the hd cua co tim co giai doan cao nguyen la do;

+) nguyen nhan: do kenh calci cham o mang TB co tim: o mang Tb co tim co chu yeu la kenh cham (kenh ca cham hay kenh Ca-Na) va cung co kenh Na nhanh. Thoi gian mo kenh Ca cham keo dai toi vai phan muoi giay, lam cho duy tri lau dai trang?1 luong lon ion Ca va Na dI vao trong Tb co tim tao dg cao nguyen cua dien the hd?thaI khu cuc

+) Nguyen nhan do mang co tim giam tinh tham voi ion K+: khi xhien dthe ko tao dc giai? K+ ko ra khoi TB ?hd tinh tham cua mang voi K+ giam doan taI cuc lam cho trang thaI khu cuc keo dai gop phan tao dg cao nguyen cua dien the hd.

Nguyen nhan nay chi co owr co tim ko co o co van.

*) Tinh tro co chu ky

- tinh tro co chu ky la tinh ko dap ung voi kthick co chu ky cua co tim

- thi nghiem: ghi do thi hoat dong cua tim ech, ta thay tim ech hoat dong co chu ky, gom cac giai doan co va d•n

?- neu kthick vao giai doan tim dang co( tam thu): tim ko co them nua khi tim dang co co, tim ko dap ung voi kthick gla giai doan tro cua tim

- neu kick thick vao luc co tim dang gi•n thi tim dap ung = 1 co bop phu goi la ngoai tam thu. Sau ngoai tam thu tim gi•n ra va nghi keo dai, goi la ghi bu.

+) tim nghi bu la do xung dong tu nut xoang toi tam that roI vao gd tro cua co bop phu, nen co bop binh thuong ko xay ra cho den khi xung dong tiep theo cua nut xoang thi lai xhien co bop binh thuong

+) Tong thoi gian chu ky ngoai tam thu + chu ky tiep sau do = tong thoi gian cua 2 chu ky tiom binh thuong.

- trong giai doan tam thu tim co tinh tro, ma tim hdong co tinh chu ky nen gd tro cung lap dI lap lai 1 cach deu dan do do tim co tinh tro co tim chiu kthick lien tiep, tim ko bi co cung phu hop voi chu ky?chu ky bom mau cua tim

*) Tinh nhip dieu cua co tim.

- tinh nhip dieu la kha nang tu phat sinh ra cac xung dong nhip nhang cho tim hd, dc thuc hien boi he thong nut tu dong

- do su do ri ion Na vao Tb nut xoang lam nut nay tu hung phan va hung phan phat sinh deu dan, nhip nhang

- ngoai nut xoang co knang tu phat xung dong, cac phan khac cua he thong nut cung co knang tu phat xung dong: nut nhi - that, bo his, mang purkinze. Khi tim dap theo nhip phat xung cua cac phan nay goi la dan nhip lac cho.

*) tinh dan truyen cua co tim:

- tinh dan truyen lad kha nang dan tryenn xung dong cua soi co tim va he thong nut. Co tim va he thong nut co knang dan truyen xung dong voi van toc khac nhau.

=> nho tinh hung phan, tinh nhip dieu va tinh dan truyen xung dong ma tim du o trong co the hay tach khoi co the va dc nuoI duong day du thi tim van tu co bop deu dan, nhip nhang. nho tinh tro co chu ky ma tim ko bi co cung khi chiu cac kick thick lien tuc.

*) UDLS:

- trong 1 so TH tinh hung phan ptrien qua -> thuoc an than

- dtri ngoai tam thu la giam tinh hung phan

Cau 2: mo ta cac giai doancua chu ky tim va UDLS?

- Chu ky tim la 1 vong hdong cua tim gom nhi thu, that thu va tam truong toan bo

- Nguoi binh thuong co f=75 nhip/ phut thi thoi gian cua 1 chu ky tim la 0,8s gom 3 gd:

*) Giai doan tam nhi thu: (tam nhi co lai) (0,1s)

- Khi co tam nhi co lam ap suat trong tam nhi tang > trong tam that. Luc nay van nhi_that dang mo, mau dc day tu tam nhi xuong tam that

- Tam nhi thu co tac dung day not lg mau con lai xuong tam that ( 35% tong lg mau tu tam nhi xuong tthat trong 1 chu ky tim)

- Mau tu tam nhi xuong tthat o gdoan nay lam cho ap suat tam that cung tang len

*) Giai doan tam that thu :

- La giai doan tam that co lai, ban daqu sau gd tam nhi thu. Gd tam that thu chia lam 2 thoi ky:

- Thoi ky tang ap: 0,05s

+) co tam that co, ap suat trong tam that tang len > tam nhi -> van nhi_that dong lai. Ty vay trong luc nay astt<asdm ->van to chim chua mo ra(van dm) do do tky nay goi la co dang tick

+) o tky nay ap suat mau trong tam that tang nhanh

+) astt tang-> van nhi that dong lai va loi len ve phia tam nhi do do astnhi tang

- Thoi ky tong mau(0,25s)

Cuoi thoi ky tang ap, astt > asdmc va > asdm phoi -> van to chim mo ra mau phun vao DM. luc nay tthat ttuc co bop, the tick tthat nho lai, astt van cao, mau ttuc dc tong vao dm

Thoi ky tong mau chia lam 2 thi:

+) thi tong mau nhanh: la thi bdau cua tky tong mau, trong thi nay 4/5 lg mau cua tam that dc tong vao dm

+) thi tong mau cham: la thi tiep theo cua thoi ky tong mau nhanh, thoi gain dai hon,1/5 lg mau con lai cua tam that dc tong vao dm

*) Giai daon tam truong toan bo (0,4s)

- Tam that bat dau gi•n ra, do la gd tam truong toan bo( trong luc do tam nhi van dang gi•n)

- Khi co tam that gi•n thi astt giam, khi astt<asdm chu va dm phoi thi van to chim dong lai

- Tam that tiep tuc gi•n, do la tky gi•n dang tick, as tham thau tiep tuc giam nhanh cho den khi astt<astnhi thi van nhi that bat dau mo ra kthuc thoi ky gi•n dang tick, mau dc hut tu tam nhi xuong tam that

+) Day that nhanh: sau khi can nhi that mo ra mau dc hut xuong tthat nhanh

+) Day that cham: sau do mau xuong tthat cham dan sau thi day that nhanh

- Giai doan tam truong toan bo la thoi gian de mau tu tam nhi xuong taam that chiem 65% tong lg mau tu tam nhi xuong tam that trong 1 chu ky tim

*) chu ky tim lsang: 2 chu ky:

- gd taam thu: tam that co, tim bom mau vao dm

- gd tam truong: tam that gi•n?????

*) UDLS :

- nguoi bi suy tim ng ta dung nghiem phap do ap luc tinh mach trung tam xem knang hut mu ve tim

- Bieu hien ben ngoai cua chu ky tim : so mom tim nguc biet chu ky tim bthuong hay ko bthuong, 1 so TH benh ly co lung muu, tieng T1 tach doi...

Cau 3 : trinh bay co che TK dieu hoa hd tim va UDLS

TK thuc vat : giao cam va pho giao cam

- he TK pho giao cam: trung tom TK pho giao cam dieu hoa hoat dong tim nam o hanh n•o, do la nhan cua day X. cac soi truoc hach cua day X dI toi hach pho Giao cam chi phoi hd cua nut xoang va nut nhi that

+) thi nghiem: cat day Tk X o daon co cua cho, dung dong dien kthick vao dau ngoai bien cua day X thay, neu kick thick voi cuong do vua phaI lam tim dap cham va yeu. Nuu tang cuong do kick thick thi tim ngung dap nhung neu cu kick thick tiep tuc thi tim lai dap tro lai, do la hien tg thoat uc che. Tim thoat uc che la do bo his phat xung dong, vi bo his ko chiu su chi phoi cua day X or do tim ngung dap mau ve tam nhi nhieu hon lam ap suat mau trong tam nhi tang len, kick thick nut xoang phat xung dongtro lai

Nhu vay, td cua day X doi voi hd cua tim:

(+) giam tan so tim

(+) giam luc co bop tim

(+) giam toc do dan truyen xung dong trong tim

(+) giam tinh hung phan cua co tim

He TK pho giao cam td len tim thong qua hoa chat trung gian la acetyl cholin

- he TK giao cam: Tk giao cam dieu hoa hoat dong tim nam o sung ben chat xam tuy song doan lung 1-3, tu day cac soi TK dI den hach giao cam nam gan cot song. Cung co 1 so soi xphat tu sung ben chat xamtuy song doan co 1-7 dI den hach giao cam den tim gay tac dung ngc voi td cua day X tang(nhip, luc, truong luc, hung phan, dan truyen)

Hei TK giao cam td len hd cau tim thong qua hoa chat trung gian noradrenalin

*) cac phan xa dhoa hdong cua tim

- binh thuong co:

+) 1 phan xa giam ap luc mau tang o quai DM C or xoang Dm canh, td vao cac receptor nhan cam as o day, lam xh cac xung dong cahy theo day TK hering ve hanh n•o, kick thick day X lam tim dap cham va yeu-> giam HA

+) 2 pxa lam tang nhip tim: khi Cm O2 trong mau giam, [CO2] tang or HA giam, tac dong len receptor o than DM canh va DMC, lam xh xung dong dI theo day TK Hering ve hanh n•o, uc che day X, lam cho tim dap nhanh.

+) 3 px tim- tim: px khi tim u mau khi mau ve tim nhieu no lam cang gi•n tam nhi dbiet tam nhi phai. xung dong truyen ve hanh n•o qua cac soi cam giac cua day X -> uc che day X -> tim dap nhanh manh thanh toan tinh trang u mau.

- phan xa bat thg:

+) 4 px mat tim: no phat sinh khi ep lien tuc ve nh•n cau se kick thick dau mut day X, tao xung dong theo daay V ve hanh n•o -> khick thick day X -> tim dap cham

+) 2 px goltz: khi dam manh vao vung nguc, thuong vi or co keo cac tang o o bung khi phau thuat , xung dong dI theo dg cam giac or TK tang len hanh n•o, dg truyen ra gay hung phan day X -> co the tim ngung dap

+) 3 phan xa hau mon - mat : khi kick thick vao vung hau mon va tang sinh mon manh truyen vao theo day TK tang truyen ra -> kick thick day X -> tim ngung dap

*) anh huong cua vo n•o va 1 so trung tam TK #:

- hd cua vo n•o: cac cam xuc manh nhu hoi hop, so h•I lam bien doi nhip tim, khi hoi hop tim dap nhanh, khi so h•I or qua xuc dong nhip tim co the tang len nhung cung co khi tim dap cham, tham chi ngung dap

- trung tam ho hap anh huong den trung tam day X owr hanh n•o uc che trung tam day X, tim dap nhanh hon 1 chut. Khi tho ra trung tam day X thaot uc che lam tim dap cham lai 1 chut

- trung tam nuot o hanh n•o anh huong den trung tam day X: khi nuot, ttam nuot uc che trung tam day X, lam tim daapj nhanh hon 1 chut

*) UDLS

Cau 4 : Trinh bay co che noi tai, co che the dich dhoa hd tim va UDLS

*) noi tai :

- Thi nghiem : tim ech co lap

+) Luon ong thuy tinh vao DM cua 1 con ech

+) Quan sat: qua tim day mau van co va gi•n

Dung dung dich ringer hut vao nha ra sau 1 thoi gian -> qua tim trang

-> qua tim tu dieu chinh luc co phu hop voi lg dich trong buong tim

- Dinh luat starling: luc co cua co tim ty le thuan voi chieu dai cua soi co truoc khi co

dieu nay co y nghia la khi mau tinh mach ve tam that cang nhieu thi co tam that cang bi keo dai ra, lam cho cac soi actin va myosin goi nhau o vi tri thuan loi hon va tao ra luc co co cang manh. Tuy vay khi co tim gi•n ra o 1 muc do nhat dinh thi co tac dung lam tang luc tam thu cua tim, nhung khi co tim bi gi•n ra qua muc thi cac cau noi o soi myosyn kho gan vao cac diem hd tren soi actin, nen cac soi catin va myosin kho truot vao nhau, lam giam or lam mat truong luc co tim, nhu vay luc tam thu se giam

UD: chinh nho co che tu dieu hoa nay ma tim co kha nang tu thay doi luc tam thu theo tung dk cua co the, moi khi mau ve tim nhieu trong tky tam truong lam cho tamthat gi•n ra, thi o thi tam thu tim co bop manh len de day mau vao dm. nhu vay, lam tang luu lg tim, tranh u dong mau trong tim.

UD:de tim khoe thi phaI vd the thao thg xuyen

*) the dich:

- hormon tuyen giap: hormon T3, T4 co tac dung lam tim dap nhanh

doi voi benh nhan bi uu nang tuyen giap luon co nhip tim nhanh, ngc lai dvoi bnhan nhuoc nang tuyen giap co nhip tim cham

Benh nhan cuong giap ( Basedo) -> suy tim

- hormon tuy thg than: hormon adrenalin co td lam cho tim dap nhanh, ngoai ra con lam co mach, tang HA

- nong do CO2 va O2

+) [O2] giam, [CO2] tang trong mau dm lam tim dap nhanh. Nguoc lai, [CO2] giam, [O2]tang trong mau dm sse lam giam nhip tim, nhung neu khi CO2 tang qua cao thi co tim se bi ngo doc or neu khi CO2 giam thap qua co tim se thieu dinh duong, thi tim dap cham lai

- nong do ion Ca2+ trong mau tang lam tang truong luc co tim

- nong do ion K+ trong mau tang lam giam truong luc co tim

- pH cua mau giam lam tim dap nhanh

- nhiet do co the : khi than nhiet tang lam tim dap nhanh, trong TH bi sot tim dap nhanh. Ngc lai nhip tim giam trong ha nhiet nhan tao( trong mo tim phia ha nhiet nhan tao xuong con 25 - 30 do de co the co the chiu dc voi su thieu oxi

Cau 5 : trinh bay cac bieu hien ben ngoai cua chu chuyen tim va UDLS

1. mom tim dap :

Khi ta nhin or so vao thanh long nguc phia truoc, ben trai, o khoang lien suon V tren dg giua don trai, ta thay tai do nho len, ha xuong trong moi chu ky tim do la mom tim dap. Co htuong nay la do luc co tim dang co, co tim ran lai va dua mom tim ra phia truoc day vao thanh nguc, lam cho thanh nguc o do nho len, khi co tim gi•n ra long nguc tai vtri do lai ha xuong

ud : quan sat mom tim dap cho ta biet vi tri cua mom tim tren long nguc de tien hah cac tham kham ve tim va co the dem dc nhip tim

2. tieng tim : dung ong nghe hay ap tai vao thanh nguc phia truoc ben trai, ta thuong nghe thay 2 tieng tim la T1 va T2, thinh thoang con nghe thay tieng T3 va T4

- T1(bum) : nghe tram va dai, nghe ro owr vung mom tim, la tieng mo dau cua thoi ky tam that thu, nguyen nhan gay ra tieng T1 chu yeu la do dong van nhi that. ting T1 co 2 tp chinh : tp1 la do dong van 2 la, nghe ro nhat la o vung mom tim, tp2 la do dong van 3 la, nghe ro o phan duoi bo uc trai

Ngoai ra tieng T1 con do mo cac van ban nguyet va dong mau phun vao dm

Trong 2 tp chinh, tp do dong van 2 la xay ra trc. Trong nghen nhnah phaI hoan toan, su dan truyen hung phan den tim phaI d• muon la cang muon them,lam cho 2 thanh phan nay cang cach xa nhau them -> T1 tach doi

Ngc lai trong nghen nhanh traI, tp van 2 la bi muon lai lam cho 2 tp nay rat lai gan nhau tham chi co the hoa vao nhau thanh 1 tieng duy nhat

- tieng T2 nghe thanh va ngan (tac): nghe ro o khoang lien suon 2, canh 2 ben xuong uc. Tieng T2 la tieng mo dau cho thoi ky tam that truong

Nguyen nhan gay ra T2 la do dong cac van to chim

+) T2 cung co 2 thnah phan chinh: tp1 la dong van DMC, xay ra trc 1 chut. Tp 2 la dong van DM phoi, xay ra sau tp1 do cac htg hd cua tim trai xay ra truoc 1 chut so voi hd cua tim phai

+) muc do tach doI tieng T2 thay doi theo cac thi cua ho hap: khi hit vao muc do tach doI tang len, o thi tho ra gan nhu ko tach doi

+) benh ly: T2 ko tach doI, gap o ng gia, o ng co cao ap DM phoi

. T2 lien tuc tach doI gap trong nghen nhanh phaI or op benh nhan bi ho nan 2 la or o ng bi thong vach lien nhi

. T2 tach doI ngc, gap trong nghen nhanh traI hoan toan

- khoang thoi gian giua T1 - T2 la khoang im lang ngan ( luc tam that thu)

+) bat thg giua T1 - T2 ->thoi tam thu, hep van dm, ho van nhi that

- khoang thoi gian giua T2 - T1 la khoang im lang dai ( luc tam that truong ). Bat thg T2 - T1 -> thoi tam truong

- tieng T3 va T4 dc tao ra khi buong tam that hung mau trong gd tam truong

- tieng T3 la do dot ngot ngung cang that luc tam truong, lam mau doi manh dap vao thanh tam that

- tieng T4 la do dot ngot gi•n that luc tam that thu ( luc nhi co)

- o tre em va ng tre tuoi tre thuong co tieng T3 binh thg, neu hit vao vf nin tho -> se ko thay nua nhung T4 ko bthg

T3 va T4 co tan so thap, nghe thay o tim trai or tim phai

Tren lsang ng ta nhan biet cky tim = tieng tim. Nvay, cky tim tren lsang ko cho biet hd cua tam nhi ma chi cho biet hd cua tam that.

3. Huyen ap: HA co gtri so toi thieu trong tky tam truong -> HA toi thieu

HA co gtri toi da trong thi tam thu -> HA toi da

4. Dien tam do

- do thi ghi lai dong dien hd cua tim trong qua trinh hd va co bop

Song P: song khu cuc cua tam nhi

Phuc bo Q R: phuc bo khu cuc cau tam that

Song T: song taI khu cuc cua tthat

Thoi gian PQ: tgian dan truyen nhi that

Thoi gain phuc bo QR la tgian cua phuc bo that

- UD:

+) phan tick 1 ban dien tam do cho phep danh gia tgian dan truyen dthe hd trong he thong nut tu dongva trong khoi co tim. Qua viec xac dinh bien do cua cac song P, QRS va T o cac chuyen dao khac nhau cho phep danh gia knang khu cuc cua tam nhi, knang khu cuc va tai cuc cua tam that => danh gia dc nhip tim, trang thaI cua co tim, bchat va su phat sinh cac roi loan nhip tim

- ghi dien tam do nhieu lan cho BN tim mach giup danh gia tien trien cua benh or danh gia knang phuc hoi cnang tim trong qua trinh dtri

- ghi dien tam do tren cac VDV giup theo doi tinh trang the luc va danh gia hieu qua bai tap dvoi tung VDV

Cau 6 : Huyet ap dm, cac loai huyet ap, cac yeu to anh huong toi huyet ap, y nghia cua tung loai huyet ap va UDLS

*) DN huyet ap : mau chay trong dm co 1 ap suat nhat dinh goi la huyet ap. Trong do mau trg dm co 1 ap luc co xu huong day thanh DM gi•n ra, thanh DM lai co 1 suc ep nguoc tro lai. Suc day cua mau goi la huyet ap, suc ep cua thanh DM gla thnah ap. Hai ap luc nay can bang nhau

- mau luu thong trong DM la do luc day mau cua tim thang luc can mau cua DM, do do mau luu thong trg DM voi 1 toc do va ap suat nhat dinh

- Do thi ghi lai ha co cac song :

+) song anpha: the hien su thay cua ha theo hd tim. HA tang o tky tam thu, giam o thi tam truong

- song beta : la tap hop cua song anpha, the hien su bien doi HA theo hd ho hap. Khi hit vao HA tang, khi tho ra HA giam

+) khi hit vao : trung tam hh hung phan se uc che trung tam day x o hanh n•o, do do tim dap nhanh va HA tang-> co che TK

+) co che ho hap :khi hit vao ap suat trong long nguc am hon nen mau ve tim nhieu, lam cho tim dap nhanh va Ha tang. o thi tho ra thi ngc lai

- song gama : la dg loi dinh cua cac song beta, song nay the hien su bien doi cua HA theo hd co gi•n cua DM

*) cac laoi HA

- huyet ap tam thu (hap ap toi da) : la tri so HA cao nhat trg chu ky tim do dc o tky tam thu, phu thuoc vao luc tam thu va the tick tam thu cua tim

+) theo WHO : Hatt = 90 - 140mmHg

>= 140mmHg : tang HA ; <90mmHg : giam HA

HA tam thu tang trong ld, do ho van dm chu, giam trg suy tim, 1 so benh ly lam ha HA

- HA tam truong( HA toi thieu)

+) la tri so HA thap nhat trong chu ky tim, ung voi tky tam truong

+) HAttr phu thuoc vao trg luc cau mach mau

+) theo WHO: Hattr = 60 - 90mmHg; >=90mmHg la tang HA

HA tam truong tang khi giam tinh dan hoi cua thnah mach( xo vua DM) khi co mach, HA tam truong giam khi gi•n mach( gap trong soc phan ve)

UD: trong benh tang HA , neu chi HA tam thu tang cao thi chua nang, neu ca HA tam thu va tam truong deu cao thi ganh nang doi voi con tim rat lon, vi vay thi suat thoi gian tam that hd deu phaI vuot qua muc cao HA tam trg moi co hieu luc bom mau -> tam that de bi phi dai va dI den suy tim

- hieu so hieu cua toi da va toi thieu = 30-40mmHg binh thg co the lon hon. Day la dieu kien cho mau luu thong trong DM. khi HA hieu so giam goi la "HA ket" tuc la tri so HA tam thu rat gan voi HA tam truong day lf dau hieu cho thay tim con it hieu luc bom mau lam cho tuan hoan mau bi giam or bi u tre

HA hieu so tang cao trong van dong

- HA trung binh la tri so ap suat trung binh dc tao ra trg suat 1 chu ky tim, la tri so HA ko doi dac trung cho che do HA dao dong do tim lam viec thay doi

Hatb = Hattr + 1/3 Hahs

*) cac yeu to AH' den HA

P = Q.R

P: huyet ap

Q: luu lg tim: la lg mau ma tim tong ra DM trong 1 phut: Q = V.f

V: the tick tam thu lg mau ma tim bom vao DM trong 1 lan co bop

f: tan so tim trong 1 phut

R: suc ca ngoai vi

- khi tim co bop manh, the tick tam thu tang lam luu lg tim tang -> HA tang

Trong van co manh mau ve tim nhieu, luc tam thu tang -> HA tang

Khi suy tim, luc co co tim ngan, lam luu lg tim gioam -> giam HA , cac thuoc tro tim lam tang luc tam thu -> HA tang

- khi tan so tim qua 140 nhip/phut -> thoi gian tam trg ngan, mau ve tim it -> tim co bop rong -> nhip nhanh, suy tim ko du cung cap mau

- HA phu thuoc vao do quanh cua mau : do quanh cua mau do lg pr quyet dinh. Trong DK binh thg do quanh cua 1 ng iot thay doi

+) do quanh tang -> suc can tang -> HA tang va ngc lai

+) khi bi mat mau va truyen dich -> do quanh giam -> HA giam. Vi vay khi truyen mau phia truyen nhung dung dich co cao phan tu tot nhat la tryen mau.

+) do quanh cau mau tang : gap trg tinh trang mat nc nhu khi bi non, ia chay

- HA phu thuoc vao : the tick tuan hoan : V tang -> HA tang

+) so lg hong cau tang -> HA tang

ung dung truyen cham

Cau 7 : trinh bay cac nguyen nhan tuan hoan tinh mach va UDLS

- suc bom cua tim : mau cung chay dc tronmg he thong tinh mach la nho chenh lech ap suat giua dau va cuoi tinh mach, su chenh lech nay la do tim tao ra. Luc day mau cua tim thang dc suc can cua mach nen mau chay o trong DM voi ap suat nhat dinh, ap suat nay giam tu dm den mao mach, o cuoi mao mach van con 1 ap suat, ap suat mau o dau tinh mach vao khoang 10mmHg, con o cuoi tinh mach va o tam nhi phai la 0mmHg do do mau chay dc tu tinh mach ve tim

- suc hut cua tim : trong luc tam that truong, ap suat trong tam that giam xuong, tao ra suc hut mau tu tam nhi xuong tam that va tu TM ve Tim

Mat khac, khi tam that thu bom mau vao Dm loam san van nhi that ha xuong, cung co tac dung hut mau tro ve tim

- do lonh nguc :

+) binh thuong as trong long nguc hoi thap hon so voi as khi quyen, do as am trong khoang mang phoi. Khi hit voa, the tick long nguc gi•n ra,lam as cangf am hon. AS trong long nguc giam lam cho cac tinh mach lon o day gi•n ra, as trong TM giam, hut mau tu tieu tinh mach va mao mach ve tim

+) 1 yeu to nua la: binh thuong qua tim chiem 1 the tick trong l;ong nguc, khi tam thu tim co nho lai lam khoang long nguc rong hon, AS trong long nguc cang am hon, lam cho cac tinh machtrong long nguc va tam nhi gi•n ra, tao dk hut mau ve tim

- do co co:

+) tinh mach nam xen vao cac soi co, nen khi co co bop ep vao cac mach mau, don mau cahy theo chieu van trong tinh mach

+) o chi duoi, khi cac co van dong don mau dI len tim, o o bung nho co co thang va co thanh bung ma mau dc don ve tim

- Do Dm: Dm lon va TM lon dI chung trong 1 bao xo, thg 1 dm dI kem voia 2 TM. Moi lan DM dap co tac dung don mau trong TM ve tim.

- anh huong cua trong luc: khi dung trong luc anh huong tot den viec dua mau TM phia tren ( dau, nat, co) ve tim va anh huong ko thuon loi dvoi tuan hoan tinh mach phia duoi tim. Tuy vay, cac TM o phia duoi tim co he thong van nen mau van chuyen dich dc ve tim

*) UDLS

Cau 8 : trinh bay cac chuc nang cua mao mach va UDLS

- Chuc nang trao doi chat o mao mach. Tuan hoan mao mach co chuc nang het suc quan trong la chuc nang TDC giua mau va dich ke o cac mao mach thuc su

- CaC chat khi nhu O2 , CO2 tan trong lipid len qua trinh trao doi khi xay ra o mao mach theo co che khuyech tan don thuan theo bac thang ap suat, tuc la cac chat khi dI tu noI co phan ap cao toi noI co phan ap thap: khi O2 dI tu mo <-> mau, con CO2 dI tu mo -> mau

- Nuoc va cac chat hoa tan trong nuoc ( cac ion, glucoe, aa, ure..) dc tra doi qua cac khe, cac lo cua mao mach theo su chenh lech cac ap suat giua mau va dich ke. Do su chenh lech do ma nc va cac chat hoa tan dc "loc" o doan dau mao mach( mao DM) va dc " taI hap thu" o doan cuoi MM( mao TM)

Ve so do

*UDLS: trong benh suy tim: HA mao DM giam, mao TM tang -> phu tim

Phu than: Pkeo giam-> giam Pr mau -> ko giu dc nuoc trong long mach -> thoat ra dich ke

Cau 9 : ap suat am trong khoan mang phoi : dinh nghia, co che hinh thanh, bien doi trong chu ky ho hap, y nghia va UDLS

DN: A's trong khoang mang phoi thap hon A's khi quyen dc goi la A's am trong khoang mang phoi . A's am trong khoang mang phoi co the do dc bang cach do truc tiep hoac do gian tiep

Co che hinh thanh ;bien doi trong chu ky ho hap :

Mo phoi co tinh dan hoi do do treo tinh chat cua cac soi dan hoi thi neu cang bi keo cang ra thi luc co lai cang lon. Phoi o thi hit vao bi cang gi•n ra do do co xu huong co ve phia ron phoi. Phoi cang gi•n no to thi luc dan hoi co ve phia ron phoi cang lon trong khi do long nguc dc coi la 1 binh kin va cung tuy co kha nang dan hoi nhung nho hon rat nhieu so voi nhu mo phoi. o thi hit vao long nguc tang kinh thich, la thanh ap sat vao thanh nguc con la tang ap sat vao phoi, do tinh chat dan hoi cua phoi la tang co xu huong tach ra khoi la thanh lam cho the tich trong khoang ao cua mang phoi tang len. Theo dinh luat vat ly: trong mot binh kin, neu nhiet do ko thay doi, ap suat trong binh se giam khi the tich cua binh tang len. Chinh vi ly do tren nen khi the tich cua khoang ao mang phoi co xu huong tang len thi A's trong khoang ao se giam xuong lam cho A's trong khoang mang phoi d• am lai cang am hon. Khi phoi cang no ra o thi hit vao thi luc dan hoi co lai cua phoi cang lon va lam cho A's cang am. Khi phoi cang thu nho lai o thi tho ra thi A's se bot am hon do luc dan hoi co lai ve phia ron phoi giam xuong, la tang giam bot luc co tach khoi la thanh va the tich o khoang ao dan tro ve trang thaI ban dau.

Ngoai ra nguoi ta con dua vao su tang truong kich thich cua long nguc o dua tre sau khi sinh, kich thuoc cua long nguc thuong tang nhanh hon phoi. Vi the khien cho thanh nguc va dI lien voi no la la thanh co xu the tach khoi may ngoai cua phoi tuc la tach khoi la tang vi la tang ap sat mat ngoai cua phoi. Mat khac ap suat khi quyen thong qua duong dan khi tac dong vao cac phe nang luon lam phoi no them va bam sat theo thanh nguc. Do tinh chat dan hoi cua mo phoi nen phoi co xu huong co nho lai ko theo do no cua thanh nguc. Su co nguoc chieu nhau( long nguc no to ra, mo phoi co nho lai) d• tao ra ap suat am trong khoang mang phoi

1 yeu to nua gop phan tao ap suat am trong khoang mang phoi la dich mang phoi dc bom lien tuc vao cac mach bach huyet

- o cuoi thi tho ra binh thuong a's am trong khoang mang phoi khoang -4mmHg

- o cuoi thi hit vao binh thg a's am trong khoang mang phoi khoang -7mmHg

- Khi hit vao het suc a's am trong khoang mang phoi co the xuong toi -30mmHg

- Khi tho ra het suc a's am trong khoang mang phoi con khoang -1mmHg

*y nghia:

AS am trong khoang mang phoi co y nghi db quan trong trong ly hoc ho hap va tuan hoan

- AS am trong khoang mang phoi lam cho phoi de dan mo ra bam sat voi thanh nguc lam cho la tag luon dinh sat vao la thanh, lam cho phoi dI theo cac cu dong cua long nguc 1 cach de dang

- AS am trong khoang mang phoi lam cho long nguc cps as thap hon cac vung khac nen mau ve tim de dang va mau len phoi de dang, lam nhe ganh cho tim phai

- AS am trong khoang mang phoi lam cho hieu suat tao doi khi dat dc cao nhat vi khi hit ko khi vao phoi nhieu nhat la luc ap suat am nhat va mau ve phoi nhieu nhat tao nen su tdoi khi tot nhat nho su tg dong thong khi va tuoi mau phoi

*UDLS:

- ap suat am tro len duong khi tran dich, tran mau, tran mu, tran khi mang phoi, khi bi vet thuong long nguc.

- thung mang phoi tu ngoai vao -> ap suat duong -> ho hap dao nguoc -> khi hit vao phoi xep lai. Nuu nang gay lac lu trung that ( tim + phoi deu rung ) -> tu vong nhanh

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

Cau 12 : trinh bay qua trinh van chuyen CO2 va UDLS

Trong mau CO2 dc vc duoi hai dang

- dang hoa tan chiem 0,03mlCO2/ 100ml mau. co gia tri luon nhung no lai dang trao doi truc tiep

- ket hop( 3 dang);

+ Co2 dc gan lonh leo vao nhom NH2 cua ptu globin cua hemoglobin -> carbonamino hemoglobin

HbNH - COOH?HbNH2 + CO2

Or HbCO2 ( phu thuoc vao PCO2) (20%)?Hb + CO2

+ ket hop voi pr huyet tg rat it

+ ket hop voi muoi kiem/ htg (NaHCO3) dao thaI dc rat nhieu CO2 (70%) vtro chu yeu nho carbonic anhydrase (CA)/HC

*) Thi nghiem( td cua PCO2) hieu ung haldaue

Cho mau thanh phan giau O2 va ngheo O2 vao PCO2 khac nhau -> dt vc CO2 (Ve so do thi)

- o phoi ngheo o2 trong mau -> tang knang nha CO2 cua mau va ngc lai

- mo giau O2 trong mau -> giam [CO2] mau, tang knang gan ket Hb + CO2

*) cac yeu to anh huong den su VC CO2 cua mau

- phan ap CO2: mau vc CO2 xuoI dong bac thang nong do tu PCO2 cao( mpp, cquan) den P CO2 thap (phe nang). P CO2 tang se lam tang [CO2] trong mau, tang muc do vc CO2

- P CO2: khi P CO2 trong mau tang, O2 se gan voi Hb. Su gan O2 voi Hb se lam giam aI luc cua Hb voi CO2 do do lam giam su vc CO2

- hien tg di chuyen ion cl-: khi mau toi mo, CO2 khuyet tan tu mo vao huyet tg roi vao HC. Trong HC nho AC CO2 gan H2O -> H2CO3. acid nay ply tao thanh HCO3- va H+. ion H+ ket hop voi Hb vi Hb cung la 1 he dem rat manh. Ion HCO3- trong HC tang len, HCO3- se khuyech tan thuan hoa ra huyet tg doi cho cho ion cl- tu htg dI vao HC nho 1 pr mang bicarbonat - clorua tren mang HC, lap lai thang = dien tick. Khimau toi phoi co nhg htuong ngc lai

Kq: Co2 vao htg thi cl- vao HC va ngc lai

- su thay doi cua pH: trong mau, CO2 ton tai duoi dang H2CO3 va BHCO3, binh thg BHCO3/H2CO3 ko thay doi nen ph on dinh. Khi 1 acid manh vao mau, no pu voi bicarbonat -> H2CO3-> CO2 + H2O, CO2 dc dua ra ngoai phoi. khi kiem manh xam nhap vao mau no pu voi H2CO3 -> kiem yeu hon, lg CO2 tho ra se giam di. nhu vay, de on dinh pH co che dieu chinh cg do ho hap lam thay doi [CO2] trg mau

*) VC CO2 tu mo den phoi

- khi mau DM toi cac mo, do chenh lech phan ap. CO2 tu dich ke khuyech tan vao htg duoi dang hoa tan, lam [CO2] htg tang, CO2 se vao HC. Trong HC 1 phan CO2 ket hop voi Hb duoi dang HbCO3, con phan lon CO2 ket hop voi H2O. H2CO3 se ion hoa thanh HCO3- va H+, HCO3- se khuyech tan tu HC ra htg ket hop voi pr va cac nmuoi kiem cho cac bicarbonat. Nong do CO2 cua mau tang, mau vc CO2 theo dg tinh mach ve tim phaI roi len phoi. Nhu vay, mau TM co [O2] thap va [CO2] cao

- khi mau TM qua phoi, cac qua trinh xay ra theo chieu gnc lai, CO2 o dang hoa tan trong htg khuyech tan ra phe nang. Trong HC Hb CO2 phan ly, CO2 tu HC khuyech tan ra hyet tg roi lai khuyech tan sang phe nang. Trong khi do tai huyet tg cac biccarbonat phan ly. HCO3- vao HC cung voi H+ tao thanh H2CO3 nho AC lai khu H2O cho CO2 khuyech tan ra htg de roi CO2 tu htg lai khuyec tan sang phe nang. CO2 khuyech tan tu htg sang phe nang lam [CO2] trong mau giam, mau tro thanh mau DM co [CO2] thap va [O2] cao

Cau 13 : trinh bay qua trinh sinh ly hoc cac khoang chet, thong khi phe nang van y nghia cua no

- thong khi phe nang: la muc ko khi trao doi o tat ca cac phe nang trong 1 phut. Lien tuc phantick thanh phan ko khi trong 1 lan tho thi thay luc dau thanh phan ko khi rat giong khi hit vao ve sau ty le CO2 tang len, O2 giam dI gan giong ko khi phe nang. Nhu vay, ko khi tho ra ;a hon hop cua 2 thu ko khi, 1khi co trao doi khi voi mau va dc dung trong cac phe nang; 1thu khi ko trao doi khi voi mau va dc dung trong dg dan khi va dc gla khoang chet cua bo may ho hap

+) khoang chet giaI phau: la khoang ko gian trong bo may ho hapko co dien trao dooi khi voi mau, khoang nay baop gom toan bo cac dg dan khi

+) khoang chet sinh ly: la lkhoang chet giaI phau cong them cac phe nang ko trao doi khi voi mau dc vi nhung dk nao do nhu so hoa phe nang or mao mach vao phe nang co that

The tick ko khi trong lhoang chet gla the tick khoang chet or the tick chet, the tick khoang chet luon thay doi vi cac ong dan klhi cua bo may ho hap ko phaI la nhung ong ran cung. The tick khgoang chet Tb khoang 140ml

Thong kkhi phe nang chinh la muc thong khi co hieu luc vi no tham gia td khi. Tu cong thuc tren ta thay tho sau co loi hon tho rong vi tho cham va sau thi thong khi khoang chet giam, thong khi phe nang tang

Trong pp duong sinh tho cham, tho sau lam tang ko khi phe nang, tang hieu qua trao doi khi

Cau 14 : mo ta cac co che dieu hoa ho hap va UDLS

Gom 2 co che : TK va the dich

*) than kinh:

Binh thg ho hap dc duy tri tu dong, nhip nhang la nho co trung tam ho hap o hanh n•o deu dan phat ra cac xung dong lam cho cac co ho hap co, gi•n theo 1 nhip nhat dinh

- moi trung tam ho hap co 3 phan:

+ trung tam hit vao namg trc hanh n•o

+ trung tam tho ra nam sau hanh n•o

+ trung tam dieu chinh tren hanh n•o

- trung tam hit vao dc hung phan xung dong dI 2 huong

+) hug 1 dI den co ho hap kick thick co co ho hap

+) huong 2 td len trung tam dieu chinh nam o cau n•o

- trung tam dieu chinh dc hung phan TB bat dau phat xung dong tac dung den trung tam tho ra, dongtac tho ra thuc hien -> uc che trung tam hit vao -> trung tam ho hap hd nhip nhang va mang tinh tu dong, 16 - 18 lan/phut vuot qua 24lan -> rooi loan ho hap, duoi 10 lan cham gay uc che CO2, thieu O2

- dau TK tham gia dieu hoa ho hap( day X)

Thi nghiem: ghi dien the hdd tren doi cam giac cua day X, thay xh trung tam ngung tho nam o duoi hanh n•o la trung tam chinh -> hoat hoa, kick thick, hung phan, tac dung trung tam hit vao gay co co ho hap -> phoi: lam ko khi tu ngoai vao phoi -> phe nang cang gi•n

Cam thu cang gi•n o phe nang -> day X chi phoi den phe nang cam thu day X o phe nang bi kick thick -> uc che trung tam ngung tho -> trung tam ngung tho ko hung phan hit vao nua, trung tam hit vao kick thick trunn tam dieu chinh -> hung phan trung tam tho ra -> tho ra dua ko khi tu phe nang ra ngoai -> phe nang kocang gi•n nua -> cac day X ko kick thick -> ko kick thick trung tam ngung tho -> ko kick thick hit vao

- day cam giac nong (db day V)

Day V thay doi hd co quan ho hap, kick thick nhe day V -> dong tac tho sau; kick thick manh day V -> dong tac ngung tho

- nhung thuoc te, me -> anh huong den hd ho hap

- 1 so trung tam khac cung anh huong :

+) trung tam nuot: khi trung tam nuot hung phan se uc che ho hap do do khi dang nuot ta nin tho pxa nay lam cho thuc an khi nuot ko dI vao dg dan khi

+) vung duoi doi: ( trung tam chong nong, chong lanh)

+) thay doi nhiet do o moI truong xung quanh se thong qua vung duoi doi gay nhung bien doi ho hap nham gop phan dieu hoa than nhiet

Trong TH bi sot cao cung co the lam cho cac trung tam ho hap phaI tang cuong hd do khi sot cao lam tang cac qua trinh chuyen hoa, lam cho nhu cau ve O2 tang len

Vai tro than nhiet o ng co the anh huong den hd cua cac trung tam ho hap nhung ko truc tiep ma qua qua trinh chuyen hoa chat va nang lg va chi co td khi than nhiet tang cao hon binh thg do sot or giam hon binh thg trong cac trg hop ha than nhiet nhan tao de phau thuat or de dieu tri

- he TK thuc vat: pho giao cam: co co va giao cam: gi•n co

- vo n•o: khi thay doi cam xuc cung lam thay doi nhip ho hap, mat khac vo n•o va 1 so trung tam cap cao khac con dk ho hap tuy y qua dg TK vo n•o- tuy de chi phoi hd cac co ho hap. Tuy nhien td nay chi xhien va duy tri trong 1 chung muc nhat dinh

*) The dich: thong qua mau noi mo

- [CO2], [O2], [ph mau]

- [CO2] tang gay pxa ho hap tang. thong khi tang lam tan gdao thaI CO2 khoi co the, khi [CO2] trong ko khhi tho tang cao lam cho phe nang thi du co tang ho hap cung ko thia dc nhieu CO2 hon nua -> nhiem doc CO2

[CO2] bthg trg co the co td kivk thick duy tri ho hap, neu [CO2] thap qua -> ngung tho, vi cap cuu ng ngat = hoo hap 95% O2 va 5% CO2

Trong co the CO2 chu yeu tac dong vao vung nhan cam hoa hoc o trung tam ho hap va dong thoi CO2 cung tac dong vao recptor nhan cam hoa hoc o xoang DM canh va quai DM chu ma ko gay nen Pxa tang ho hap

- [O2]: khi lam giam PO2 trong ko khi tho -> PO2 trong phe nang cung giam theo

Khi [O2] xuong thap duoi 60mmHg -> td tang thong khi luc dau lam tang do sau cua tho, sau lam tang ca so lan tho

PO2 thap td vao cac cam thu hoa hoc cua DM canh va quai DM chu lam trung tam ho hap tang man cam voi CO2 -> co tac dung trong dieu hoa ho hap

Cau 15 : trinh bay hien tuong co hoc o mieng : nhai, nuot va UDLS

*) nhai:

- nhai = rang: rang cua de cat, rang ham de nghien, cac co ham khi cung lam viec se lam cho 2 ham rang khit lai

- Hau het cac co nhai deu co nhanh van dong cua day V hi phoi

- trung tam nhai nawmf o than n•o

- phan xa nhai dien ra nhu sau: thuc an ep vao mieng gay uc che cac co nhai lam ham duoi tre xuong va lam cang co ham, ca co ham co lai, hma duoi nang len lam 2 ham rang kit lai dong thoi ep nen thuc an vao mieng, cac co nhai lai bi uc che. Cu nhu the dong tac nhai dc lap dI lap lai

- nhai rat quan trong voi su tieu hoa thuc an vi acc enzym tieu hoa chi tac dung tren be mat cua cac ptu thuc an. su nghien thuc an thanh cac ptu nho roi tron lan voi nc bot vua lam tang dien tick tiep xuc cua thuc an voi enzym tieu hoa, vua lam cho thuc an dc vc de dang ma ko lam ton thuong ong tieu hoa, rieng doi voi rau qua nhai con qtrong o cho no pha vo mang boc xenlulose de nhung phan dinh duong o ben trong co the dc tieu hoa va hap thu

*) nuot: la 1 dong tac nua tuy y, nua tu dong co co che phuc tap dc chia lam 3 gd:

- gd nuot co y thuc: nen thuc an dc dat tren luoi, luoi cu dong len tren va ra sau de day thuc an vao hong. Bat dau tu day nuot tro thanh pxa tu dong(1-2s)

- gd hong ko co y thuc: nen thuc an kick thick vung nhan cam nuat o quanh vom hong, db phia tren cac cot hanh nhan. xung dong truyen ve trung tam nuot o hanh n•o theo cac soi cam giac cua day tam thoa, day IX, tu trung tam xung dong theo cac day TK V, IX, X va XII den hong va thuc quan gay co cac co cua hong theo trinh tu sau:

+) hong mem bi keo len tren de dong lo mui sau, ngan su trao ngc thuc an vao khoang mui

+) cac nep gap cua vom hong o 2 ben dc keo vao giua tao thanh 1 r•nh doc de thuc an qua do vao hong sau

+) cac day thanh am nam sat canh nhau, thanh quan bi keo len tren va ra trc boi cac co co

dong tac nay cung voi su co mat cua cac day chang lam cho nap thanh quan bi dua ra sau che kin thanh mon, ngan ko cho thuc an dI vao khi quan

+) thanh quan bi keo len tren cung lam mo rong khe thanh quan, co that hong, thuc quan gi•n ra dong thoi co thanh bung co lai day thuc an day thuc an vao thuc quan

- gd thuc quan: chuc nang chu yeu cua thuc quan la dua thuc an tu hong vao da day nho cac song nhu dong, thoi gian thuc an di chuyen trong thuc quan khoang 8 -10s. neu ng ta an o tu the dung thi thuc an se dc chuyen nhanh hon do tac dung cua trong luc keo thuc an xuong

Cac song nhu dong cua thuc quan dc kiem soat boi day TK so IX, day X ca dam roi TK Auerbach o thuc quan

Khi song nhu dong cua thuc quan den gan da day, co that da day - thuc quan gi•n ra dong thoi voi su gi•n cua phan tren da day, song nhu dong o phia sau viem thuc an day no vao da day. binh thg co that da day - thuc quan o trag thaI co truong luc de ngan su trao ngc cua thuc an acid tu da day len thuc quan

Cau 16 : nuoc bot : thanh phan, tac dung, dieu hoa bai tiet va UDLS

*) thanh phan: don vi bai tiet co ban cua tuyen nc bot dc gla salivan, moi salivan gom nang va ong dan tuyen nc bot. Long nang dc noi voi he thong ong dan phan nhanh, cac nang nc bot dc cau tao tu 2 loai TB: TB thanh dich va TB nhay

- TB thanh dich bai tiet thanh dich chua cac chat dien giaI va enzym amylase nc bot

- TB nhay bai tiet chat nhay

- cac tuyen mang tai chi bai tiet thanh dich, cac tuyen nc bot nho trong mieng chi bai tiet chat nhay, cac tuyen duoi ham va duoi luoi bai tiet ca thnah dich va chat nhay. Nuoc bot ra khoi nang co nong do ion Na+, K+ va cl- giong nhu cac huyet tg. Nhung khi nc bot chay qua ong dan, cac ion Na+ va cl- dc taI hap thu, dong thoi cac ion K+ va HCO3- dc bai tiet vao long ong. Do do [K+] nc bot cao gap 7 lan, nong do ion HCO3- cao gap 3 lan trong khi [Na+] va [cl-] chi = 1/7 - 1/10 nong do cua chung trong huyet tg

- luu lg nc bot hang ngay khoang 800 - 1500ml. pH nc bot 6 - 7,4 la pH toi thuan cho td tieu hoa cua enzym amylase nuoc bot.

* Tac dung:

- tac dung tieu hoa: enzym amylase nuoc bot co tac dung phan giaI tinh bot chin thanh duong mantose, maltriose va oligosacarid. pH toi thuan cua amylase nc bot la 7. khi thuc an vao da day, do 1 lg lon thuc an ko dc tron lan ngay voi acid cua da day nen amylase nc bot van co td trong da day va enzym nay co the thuy phan toi 75% lg tinh bot chin an vao.

- Nc bot lam am uot, boI tron mieng va thuc an tao dk cho viec nuot va nem dc thuc hien de dang

- ve sinh rang mieng: trong mieng co rat nhieu loai VK, chung de dang huy hoai cac mo va gay benh cung nhu nguon thuc an cung cap cho su chuyen hoa cua chung. Nc bot cung co 1 so chat diet VK va chua khang the tieu diet vk o mieng, ke ca nhung VK gay sau rang. Nc bot con co tac dung trung hoa acid do VK o mieng giaI phong ra or acid trao ngc tu da day len mieng

- Nc bot giup cho su noi vi no lam cho moI, luoi cu dong de dang.

*) dieu hoa bai tiet nc bot:

Tuyen nc bot la tuyen tieu hoa duy nhat ko chiu anh huong cua cac hormon tieu hoa, chung chi chiu su dieu hoa cua TK tu chu, chu yeu la TK pho giao cam. trung tam kiem soat su bai tiet nc bot la cac nhan nc bot nam o giua cau n•o va hanh n•o. cac kick thik gay tang bai tiet nc bot la nhai, ngui or nem thuc an(pxa ko dieu kien). Bai tiet nc bot cung tang len khi ta nghi den 1 mon an nao do(pxa co dk). Bai tiet nc bot giam khi ngu, met moi, so h•I or bi mat nc. vi chua lam tang bai tiet nc bot len gap 8 - 20 lan, binh thg su co mat cua cac vat tron nhan trong mieng cung lam tang bai tiet nc bot. Nc bot cung dc bai tiet nhieu khi ta nuot phaI nhung chat kick thick de giup pha lo•ng or trung hoa cac chat do trong ong tieu hoa.

- kick thick cac soi TK pho giao cam( day VII, IX) lam tang bai tiet nc bot lo•ng giau chat dien giaI va amylase nc bot

Neu cat cac day pho giao cam dI den tuyen nc bot, cac tuyen nc bot se bi teo di. nhung cat day TK giao cam ko lam anh huong den kick thuoc cua tuyen

- kick thik soi giao cam tang bai tiet nc bot giau chat nhay, khoi lg nc bot tang it hon so voi kick thick TK pho giao cam. ngay sau khi kick thick giao cam, luu luong mau giam nhung dan dan luu lg mau se tang len do su u dong cac chat chuyen hoa gay gi•n mach

*) UDLS:

Cau 18: trinh bay thanh phan, tac dung cua dich vi hon hop va UDLS

Da day bai tiet khoang 3 - 4l dich vi moi ngay. dich vi co [HCl] cao ( khoang 150ml/l, pH xap xi = 1) va chua pepsin, lipase, yeu to noi, chat nhay

- hau het dich vi do cac tuyen sinh acid nam o nmac vung than va day da day bai tiet

*) bai tiet acid HCl

HCl do TB vien bai tiet. Khi bi kick thick, TB vien bai tiet 1 dung dich chua khoang 150mmol HCl/l, pH xx=1

- TB vien chua nhung kenh nho, HCl dc tao ra o mang nhung mao cua kenh, cac kenh nay do vao long ong tuyen sinh acid

- vai tro cua HCl

+) tao pH can thiet de hoat hoa pepsinogen

+) tao pH toi thuan cho pepsin hd

+) sat khuan: tieu diet cac VK co trong thuc an, nhung ng bai tiet iot HCl de bi nhiem khuan dg tieu hoa

+) pha vo lop vo boc soi co thit

+) thuy phan cellulose o thuc vat non

+) tham gia co che dong mo mon vi va tam vi

*) nhom enzym tieu hoa

- pepsin : TB chinh cua tuyen sinh acid va TB nhay cua tuyen mon vi bai tiet pepsinogen ko hd. Ngay khi pepsinogen tiep xuc voi HCl db khi chung txuc voi 1 it pepsin dc tao ra trc do cong them HCl chung dc hoat hao thanh pepsin

Pepsin hd manh nhat o pH tu 2 - 3 va bi bat hoat o pH >5

+) pepsin la 1 endopentidase co td thuy phan pr thanh proteose, pepton va polypeptid

+) pepsin cung co knang tieu hoa cellulogen, thanh phan chu yeu cua mo lket giua cac TB cua thit, chi cac soi cellulogen bi tieu hoa thi enzym tieu hoa khac moi tham dc voa thit va tieu hoa pr

+) pepsin tieu hoa khoang 10 - 20% pr thuc an

- lipase cua dich vi co cung nguon goc voi pepsinogen. Moi ngay chung ta an khoang 60 - 100g lipid. Lipid gom triglycerid(90%) cholesterol, photpholipid va 1 so it cac loai vitamin tan trong mo

+) lipase la 1 enzym yeu va chi td len nhung lipid d• nhu tg hoa nhu lipid of sua, trung

+) lipase phan giaI triglycerid thanh acid beo va diglycerid

+) pH toi thuan cua lipase tu 4 - 6. Acid beo dc giaI phong o da day se kick thik niem mac ta trang bai tiet hormon cholecystokinin. Hormon nay kthick tuy bai tiet lipase

*) yeu to noi: do tb vien bai tiet cung HCl

- yeu to noi rat can cho su hap thu sinh to B12 o hoi trang. trong benh viem da day m•n tinh, teo nmac da day, TB vien bi pha huy, BN ko chi bi thay doi toan ma con bi thieu mau ac tinh vi vitamin B12 rat can cho su chin cua HC o tuy xuong

*) Chat nhay:

Do cac TB tuyen tam vi, tuyen mon vi va TB co tuyen sinh acid bai tiet. Ngoia ra tren toan bo be mat cua nmac, o giua cac tuyen co 1 lop TB nhay gla TB nhay be mat. Cac Tb nhay be mat bai tiet nhay quanh va kiem, ko hoa tan tao thanh 1 lop gel nhay, day len tren 1 mm bao phu nmac da day

- chat nhay gom ptu glycoprotein, giau glucid, cac ptu phospholipid va acid nucleic

- mang chat nhay day va kiem bao ve niem mac da day va ta trang khoi td an mon va tieu hoa cua acid HCl va pepsin

- binh thuong su bai tiet HCl va chat nhay, pepsin tg dg nhau nen dich vi co the tieu hoa thuc an nhung lai ko the tieu hoa dc ban than da day, ta trang. khi bai tiet chat nhay giam sut, nmac da day de bi an mon -> viem loet da day

- chat nhay cung co td boi tron lam cho thuc an dc vc de dang

- chat nhay dc bai tiet khi co cac kick thick co hoc ( thuc an cham vao nmac) or kick thick hoa hoc( acetylcholin, prostaglandin). Ngc lai cortisol va aspirin uc che bai tiet nhay

*) UDLS:

Cau 19: trinh bay co che dieu hoa bai tiet dich vi va UDLS

Giua cac bua an da day van bia tiet khoan vai ml dich vi/gio. do la dich vi co so gom chu la chat nhay, 1 it pepsinogen va hau nhu ko co acid

Khi an, dich vi dc dieu hao theo co che TK or hormon

- Co che Tk:

+) day X dong vtro kick thik bai tiet dich vi thong qua pxa dai day X - day X: xung dong tu nmac da day theo nhanh cam giac cua day X den than n•o roi truyen ve theo nhanh van dong cua day X, phan nhanh vao dam roi Tk meissner. Tu day co cac soi di den cac tuyen da day

+) He Tk ruat kick thick bai tiet dich vi thong qua cac pxa tai cho ( pxa ngan) tai thanh da day.

Tat ca cac tan cung TK cholinergic cua day X va he TKk ruot deu giai pphong ra chat truyen dat TK acetylcholin, rieng cac soi TK den TB G giai phong ra chat truyen dat Tk GRP. Acetylcholin kick thick TB vien bai tiet HCl, Tb chinh bai tiet pepsinogen va te bao co bai tiet chat nhay. GRP kick thick TB G cua nmac da day va ta trang bai tiet gastrin

Nhung tin hieu kick thick khoi dong cac pxa dai va pxa tai cho xuat phat tu n•o, db la he vien roi theo day X den da day

- co che hormon: vai tro cua gastrin va histamin

+) Gastrin do cac Tb G vung hang va ta trang bai tiet duoi td kick thick cua day X, cua su cang da day va co mat cua polypeptid trong da day

Sau khi dc bai tiet, gastrin se theo mau den cac tuyen sinh acid o day va than da day. tac dung chu yeu cu gastrin la kick thik TB vien bai tiet HCl. Gastrin cung kick thick TB chinh bai tiet pepsinogen nhung o muc do thap hon nhieu. Su bai tiet pepsinogen chu yeu chiu tac dung cua acetylcholin

+) Histamin : Histamin do cac Tb ua crom o phan day cua tyen sinh acid bai tiet. Khi co mat acid trong da day, 1 lg nho histamin dc bai tiet lien tuc trong da day. histamin gan voi receptor H2 tren te bao vien va kick thick Tb nay bai tiet HCl. Histamin co td hiep dong voi gastrin va acetylcholyn tren te bao vien: khi ca 3 chat tac dong dong thoi, su co mat cua histamin voi so lg rat nho cngx lam tang bai tiet HCl cua Tb vien len rat nhieu. Nuu uc che tac dung cua histamin = thuoc phong toa receptor H2 cua histamin thi ca gastrin va acetylcholin chi gay bai tiet 1 lg nho HCl.

+) mot so hormon khac cung anh huong den bai tiet dich vi: hormon tuy thg than adrenalin va noradrenalin lam giam bai tiet dich vi, corticoid lam tang bai tiet HCl va pepsin nhung lam giam bai tiet chat nhay. dieu tri corticoid keo dai co the gay loet or chay mau da day

- tac dung cua su thua acid len bai tiet dich vi: khi do acid cua dich vi tang cao(pH<3) co che gastrin se ngung hd do 2 ng nhan:

+) do acid qua cao lam giam or ngung bai tiet gastrin

+) qua nhieu acid trong da day gay pxa Tk uc che de giam bai tiet dich vi su uc che ngc nay dong vtro rat quan trong trong viec bao ve da day chong lai do acid qua cao co the dan den loet da day va duy tri pH toi thuan cho hd cua pepsin

Hai co che TK va Hormon bo xung cho nhau, dieu hoa lan nhau de kiem soat dich vi.

Cau 21: trinh bay thanh phan tac dung cua dich tuy hon hop va UDLS

- Tuyen tuy la 1 tuyen pha co cau truc ben trong giong ctruc cua tuyen nc bot. Phan tuy noi tiet chi chiem 1% khoi lg cua tuyen, bai tiet insulin va glucogon. Cac nang tuy bai tiet, cac enzym tieu hoa trong khi cac ong tuyen bai tiet 1 lg rat lon dung dich bicarbonat kiem. dich tuy chay vao ong wirsung, ong nay hop voi ong mat chu o bong valter roi do vao ta trang qua co that oddi

*) Thanh phan

- cac enzym: moi ngay tuy ngoai tiet bai tiet khoang 100ml dich. dich tuy la 1 dich kiem chua nhieu muoi bicarbonat va tat ca cac loai enzym can cho su tieu hoa cac chat dinh duong bao gom:

+) nhom enzym tieu hoa pr ( trypsin, elastase, carboxypeptidase)

+) enzym tieu hoa glucid (amylase)

+) enzym tieu hoa lipid (lipase, phosphopase A2, cholesterol esterase)

+) enzym tieu hoa acid nuleic (ribonulease, desoxyribonuclase)

Hau het cac enzym cua dich tuy( tru amylase va lipase) dc bai tiet duoi dang tien enzym ko hoat dong va dc boc trong cac hat zymogen. Cac hat zymogen se chuyen thnah enzym hd ngay sau khi chung txuc voi enzym enterokinase khu tru o diem ban chaI cua TB ruot. Enterokinase chuyen trypsinogen thnah trypsin, roi trypsin sse hoat hoa cac zymogen, cu the la thanh carboxypeptidase va proelastase thanh elastase. Nhu vay, trypsin dong vtro trung tam kiem soat hd cua cac enzym #

- cac enzym tieu hoa lipid la nhung hop chat hao tan trong nc, chung chi co the tan cong cac hat mo tren be mat cua chung. Vi vay, buoc dau tien cua tieu hoa mo la mo phaI dc nhu tg hoa: muoi mat va lecithin lam giam suc cang be mat cua cac hat cau mo va t\chi khi suc cang be mat giam thi cac co bop cua da day va ruot moi lam vo dc cac hat cau mo thanh nhieu hat nho co kick thuoc rat nho. Khi dg kinh cua hat cau mo giam dI mot nua thi be mat cua no tang len gap doI. qua trinh nhu tg hao mo voi enzym tang len khoang 1 ngan lan.

- Duoi tac dung cua phospholipase A2, lecithin dc thu phan thnah lysolecithin. Lysolecithin gay ton thg TB, pha vo mo tuy va gay hoai tu cac mo mo cung quanh neu enzym phospholipase A2 dc hoat hoa trong tuy.

Tuy co cac co che tu bao ve nhu sau:

+) cac enzym dc tong hop va bai tiet duoi dang zymogen ko hd va su hoat hoa cua chung binh thg chi xay ra o ruot non

+) cac enzym tieu hoa dc chua dung trong cac tui cua cac TB nang

+) cac Tb nang cung tong hop va bai tiet chat uc che trypsin

- su bai tiet dung dich bicarbonat kiem: cac TB bieu mo cua ong tuyen tuyu bai tiet 1 so lg lon dung dich bicarbonat theo cac buoc sau:

+) CO2 khuyech tan tu mau vao TB bieu mo. trong TB CO2 ket hop voi H2O duoi td cua enzym carbonic anhydrase de tao thanh H2CO3, H2CO3 phan ly thanh H+ va HCO3- sau do ion HCO3- dc vc tick cuc vao long ong

+) ion H+ tu TB vao mau trao doi voi ion Na+ tu mau vao TB theo co che VC tick cuc thu phat. sau do ion Na+ khuyech tan tu TB vao long ong

+) nc tu mau dI qua TB vao long ong de can = ap suat tham thau. Ket qua la dd bicarbonat dc tao ra o tuy, co pH=8

Thanh phan bicarbonat cua dich tuy dong vai tro qtrong trong viec trung hoa acid cua dich vi ta trang va tao ra pH toi thuan cho hd cua cac enzym tieu hoa( pH trung tinh or hoI kiem)

Cau 22: trinh bay co che dieu hoa bai tiet dich tuy va UDLS

dich tuy dc bai tiet theo co che TK va hormon

khi an, su bai tiet dich tuy co the dc chia thanh 3 gd: gd dau, gd da day va gd ruot non

- trong gd dau: su nhin, ngui, nem nghi den thuc an or nhai va nuot kick thick bai tiet dich tuy thong qua cac soi cholinergic cua day X dI den cac TB nang tuy. dich tuy cua gd nay chua nhieu enzym

- Gd da day: su cang da day khoi dong pxa dai day X - day X. Acetylcholin dc gia phong di den kick thick ca TB nang va Tb ong tuyen tuy nhung lg enzym dc bai tiet nhieu hon dd bicarbonat. dich tuy o gd nay thg it, chi chiem 5 - 10%

- Gd ruot: dich tuy dc bai tiet trong gd nay rat nhieu, chiem khoang 70 - 80%. Co 3 co che tham gia:

+) nong do ion H+ trong ta trang kick thik TB S giaI phong hormon secretin. Secretin khick thik TB ong bai tiet dung dich bicarbonat

+) cac acid beo, acid amin, peptid kick thik Tb I cua ta trang va hong trang gia phong hormon cholecystokinin. Cholecystokinin kthick ca TB nang va ong bai tiet dd bicarbonat

+) ion H+, acid beo, peptid trong long ruot cung kik thick bai tiet tuy, db la cac enzym thong qua pxa day X - day X

Cau 23: trinh bay cac thanh phan, tac dung cua dich mat va UDLS

Mat dc bai tiet duy nhat o gan, gan bai tiet mat qua 2 gd:

1. dau tien cac TB gan sx ra mat, goi la "mat dau" chua 1 lg lon acid mat, cholesterol va cac tp huu co khac. mat dc bai tiet vao cac tieu quan mat nam giua cac Tb gan trong cac be gan

2. den vach lien thuy cac tieu quan mat do vao cac ong tan, roi vao nhung ong mat co kick thuoc ngay cang lon hon, cuoi cung den ong gan va ong mat chu. Tu ong mat chu mat chay truc tiep vao ta trang or qua ong tui mat do vao tick tru trong tui mat.

Thanh phan mat o gan va o trong tui mat khac nhau

- thanh phan chu yeu cua mat la muoi mat, chiem khoang 50% cac chat hoa tan cua mat. Ngoai ra trong mat con co bilirubin, cholesterol, lecithin va cac chat dien giaI

- trong qua trinh co dac o tui mat, nc va cac chat dien giaI( tru Ca 2+) dc taI hap thu qua nmac tui mat. Muoi mat, cholesterol, lecithin dc co dac o tui mat.

*) tac dung: cac Tb gan sx ra khoang 0,5g muoi mat moi ngaytf cholesterol thuc an cung cap or dc tong hop trong cac TB gan. Cholesterol dc chuyen thanh acid cholic or acid chondesoxycholic voi lg = nhau. Cac acid nay gan voi glycin or taurin de tao thanh acid glycocholic va acid taurocholic. Muoi cua cac acid nay dc bai tiet vao mat

- muoi mat dong vtro qtrong trong tieu hoa va hap thu mo

- muoi mat giup cho qtrinh nhu tg hoa mo lam tang dien tick txuc cac hat cau mo voi enzym tieu hoa mo

- muoi mat giup cho su tieu hoa va hap thu cua cac acid beo, monglycerid, cholesterol va cac lipid khac o ruot non nho cac mixen muoi mat

- su thuy phan triglycerid thanh monoglycerid va cac acid la 1 qtrinh thuan nghich, neu monoglycerid va acid beo ko dc lay dI chung se ngan can su tieu hoa tiep tuc cua mo

- mixen muoi mat la nhung hat cau nho, dc cau tao tu 20 - 40 phan tu muoi mat. Moi ptu muoi mat gom 1 nhan sterol hoa tan trong mo va nhom cuc hoa tan trong nc. Cac nhan sterol cung voi cac ptu mo tap hop o trung tam cua hat mixin trong khi cac nhom cuc cua muoi mat quay ra phia ngoai tren be mat cua hat mixen

- cac nhom cuc tick dien am lam cho cac hat mixen hoa tan va giu dc dang on dinh trong trap. Trong qtrinh tieu hoa triglycerid, cac nhom ky nc phan tu monoglycerid va acid beo vua dc tao ra hoa tan ngay vao phan trung tam cua hat mixen do do lam giam nong do cua chung o vun lan can cac hat cau mo dc tieu hoa va ko anh huong den toc do thuy phan mo. Nhung hat mixen vc cac ptu monoglycerid va acid beo den diem ban cahi cua TB bmo ruot. o do monoglycerid va acid beo dc hap thu cac hat mixen quay tro lai long ruot de tiep tuc vc cac ptu mo khac

- neu ko co muoi mat trong ruot non, tren 40% lipid bi mat theo phan, BN bi roi loan chuyen hoa do bi mat mo.

*) UDLS

Cau 24: cac hormon: GH, ACTH, TSH : ban chat, tac dung, dieu hoa bai tiet va UDLS

a) hormon phat trien co the GH (hGH)

*) ban chat hoa hoc: GH la 1 ptu pr chua 191 acid amin trong moi chuoi don va co trong lg ptu la 22005 dvc.

*) tac dung: GH lam phat trien tat ca cac mo co knang tang truong trong co the. No vua lam tang kick thuoc Tb vua lam tang tang qtrinh phan chia TB do do lam tang trong lg co the, lam tang kick thuoc cac phu tang.

- kick thick mo sun va xuong phat trien:

+) tang lang dong pr o cac TB sun va TB tao xuong

+) tang toc do sinh san cac TB sun va te bao tao xuong

+) tang chuyen cac TB tao sun thanh cac TB tao xuong

- kick thick sinh tong hop pr :

+) tang vc acid amin qua mang TB

+) tang qtrinh sao chep ADN cua nhan TB de tao ARN

+) tang qtrinh dich m• ARN de lam tang tong hop pr tu ribosom

+) giam qtrinh thoai hoa pr va acid amin

- tang tao nang lg tu nguon lipid:

+) tang giai phong acid beo tu cac mo du tru, do do lam tang Cm acid beo trong mau.

+) chinh vi td nay ma ng ta coi td huy dong lipid cua GH la 1 trong nhung td qtrong nhat nham tiet kiem pr de dung no cho su phat trien co the

- tac dung len chuyen hoa glucid:

+) giam glucose cho muc dich sinh nang lg

+) tang du tru glycogen o TB

+) giam vc glucose vao TB va tang Cm glucose trong mau

+) tang bai tiet insulin: Cm cua glucose trong mau tang duoi td cua GH d• kick thick tuyen tuy noi tiet bai tiep insulin, dong thoi chinh GH cung co tac dung kick thick truc tiep TB beta cua tuyen tuy

*) dieu hoa bai tiet:

- vung duoi doi: GH dc bai tiet duoi su dkhien gan nhu hoan toan cau hai hormon vung duoi doi la GHRH va GHIH

- Somatostatin la 1 hormon tai cho do nhieu vung n•o va dg tieu hoa bai tiet cung co td uc che bai tiet GH

- Cm glucose giam trong mau, Cm acid beo trong mau giam, thieu pr nang va keo dai se lam tang bai tiet GH

- Tinh trang stress, chan thuong, luyen tap gang suc se lam tang bai tiet GH

- o ng vn, Cm GH trong mau cuong ron tre so sinh la 28,38 +- 10,03 ng/ml, ng truong thanh la 3,94 +- 2,09 ng/ml

b) hormon kick thick tuyen giap: TSH

*) ban chat hoa hoc: TSH la 1 glycoprotein, co trong lg ptu 28000

*) tac dung:

- tac dung len ctruc tuyen giap:

+) tang so lg va kick thuoc TB tuyen giap trong moi nang giap

+) tang bien doi cac TB nang giap tu dang khoi sang dang tru( dang bai tiet)

+) tang he thong phat trien mao mach cau tuyen giap

- tac dung len cnang tuyen giap

+ tang hd bom ion do do lam tang knang bat ion cua TB tuyen giap.

+ tang gan iot vao tyrosin de tao hormon tuyen giap

+ tang phan giaI thyroglobulin dc du tru trong long nang de giaI phong hormon tuyen giap vao mau va do do lam giam chat keo trong long nang tuyen.

*) dieu hoa bai tiet:

o ng vn bthg Cm TSH o tre em so sinh ( mau cuong ron) la 6,24+- 2,96 va ng trg thanh ( 16 - 60 tuoi) la 2,12 +- 0,91 mU/l

muc bai tiet TSH cua tuyen yen chiu su dkhien tu tren xuog cua TRH vung duoi doi va chiu su dieu hoa ngc cua tuyen dich la tuyen giap

- neu nong do TRH vung duoi doi tang thi tuyen yen se bai tiet nhieu TSH va ngc lai neu TRH giam thi Cm TSH giam. khi he thong cua duoi doi - yen bi ton thg, muc bai tiet TSH cua tuyen yen co thea giam toi mu = 0

- Nong do hormon tuyen giap anh huong den su bai tiet TSH cuat tuyen yen theo co che dieu hoa ngc am tinh va duong tinh

c) hormon kick thick tuyen vo thuong than: ACTH

*) Ban chat hoa hoc: ACTH la 1 ptu polypeptid lon gom 39 acid amin

*) tac dung

- Td len cau truc vo thg than: ACTH lam tang sinh TB tuyen vo thuong than db la TB cua lop bo va lop luoi, la nhung TB bai tiet cortisol va androgen do do cac tuyen mo to. Thieu ACTH tuyen vo thuong than se bi teo lai

- Td len cnang vo thuong than: ACTH co td kick thick vo thg than tong hop va bai tiet hormon do hoat hpa cac enzym proteinlinase A la enzym thuc day chang dau tien cua qtrinh sinh tong hop hormon vo thg than

- Td len n•o: ACTH co vai tro lam tang qua trinh hoc tap va tri nho, tang cam xuc so h•i.

- Td len TB sac to: ACTH kick thick TB sac to sx sac to melanin roi phan tan sac to nay tren be mat bieu bi da. Thieu ACTH se lam cho da ko co sac to( ng bach tang). ngc lai thua ACTH lam cho da co nhung mang sac to.

*) Dieu hoa bai tiet:

- Do nong do CRH cua vung duoi doi qdinh, khi Cm CRH tang thi ACTH dc bai tiet nhieu ngc lai khi vang mat CRH tuyen yen chi bai tiet 1 lg rat it ACTH

- Do tac dung Dhoa ngc am tinh va duong tinh cua cortislo

- Cm ACTH con dc dhoa theo nhip sinh hoc. Trong ngay, Cm ACTH cao nhat vao khoang 6 - 8h sang sau do giam dan va thap nhat vao khoang 23h roi lai tang dan ve sang.

- binh thg nong do ACTH trong huyet tg vao buoi sang khoang 10 - 50pg/ml khi bi stress nong do tang rat cao co the len toi 600pg/ml. o ng vn truong thanh( lay mau luc 8h30 sang tren nam khoe manh) Cm ACTH la 9,7773 +- 4,599 pg/ml.