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.