Cau 27: hormon tuyen giap: ban chat, tac dung, dieu hoa bai tiet va UDLS

*) ban chat:

- tuyen giap gom nhung dvi ctao dgl nang giap, co dkinh khoang 100 - 300 micromet. Nhung nang nay co chua day cac chat bai tiet dgl chat keo trong long nang va dc lot = 1 lop TB hinh khoi la nhung Tb tiet Hormon vao long nang, day TB txuc voi mao mach, dinh TB txuc voi long nang

- cac Tb nang giap bai tiet 2 hormon la triiodothyronin (T3) va tetraiodothyronin (T4). Nhung hormon nay, co nhieu cnang qtrong db la cnang chuyen hoa

*) tac dung:

- tac dung len su phat trien co the :

+ lam tang toc do phat trien

+ thuc day su truong thanh va phat trien n•o trong thoi ky bao thai va trong vai nam dau sau khi sinh

- Tac dung len chuyen hoa Tb

+ hormon tuyen giap lam tang hd chuyen hoa cu hau het cac mo trong co the. Muc chuyen hoa co so co the tang tu 60 - 100% tren muc binh thg neu hormon tuyen giap dc bai tiet nhieu

+ Tang toc do pu hoa hoc, tang tieu thu va thoai hoa thuc an de cung cap nang lg.

+ Tang so lg va kick thick cac ty the do do lam tang tong hop ATP de cung cap nang lg cho cac hd cnang cua co the

+ tang vc ion qua mang TB

- tac dung len chuyen hoa glucid

Hormon tuyen giap tac dung hau nhu tat ca cac gd cua qua trinh chuyen hoa glucid bao gom :

+ tang nhanh thoai hoa glucose o cac TB

+ Tang phan giaI glycogen

+ tang tao dg moi

+ Tang hap thu glucose o ruot

+ Tang bai tiet insulin

-> do cac td tren hormon tuyen giap lam tang Cm glucose trong mau nhung chi tang nhe

- Tac dung len chuyen hoa lipid

+ Tang thoai hoa lipid o cac cac mo mo du tru do do lam tang Cm acid beo tu do trong mau.

+ Tang oxy hoa acid beo tu do o mo

+ giam lg cholesterol, phospholipid, triglycerid o huyet tg do vay ng bi nhuoc nang tuyen giap keo dai co the co tinh trang xo vua DM. mot trong nhung co che lam giam nong do cholesterol cua hormon truyen giap do la do lam tang toc do bai xuat cholesterol qua mat roi thai ra ngoai theo phan.

Mot trong nhung co che khac nua do la hormon tuyen giap lam tang so lg cac recptor gan dac hieu voi lipoprotein ty trong thap tren TB gan do do lam tang qtrinh lay cholesterol ra khoi mau.

- tac dung len chuyen hoa vitamin: do hormon tuyen giap lam tang Cm va hd cua nhieu enzym ma vitamin lai la tp co ban de ctao enzym or coenzym nen khi Cm hormon giap tang se lam tang nhu cau tieu thu vitamin. Nuu cung cap ko du se gay tinh trang thieu vitamin

- tac dung len chuyen hoa pr: hormon tuyen giap vua lam tang tong hop pr vua lam tang thoai hoa pr. Trong thoi ky dang ptrien, td tang tong hop pr manh hon nen lam toc doo ptrien. Ngc lai khi hormon tuyen giap dc bai tiet qua nhieu, cac kho pr du tru bi huy dong va giai phong a.a vao mau.

- tac dung len he thong tim mach :

+ tac dung len mach mau : hormon giap lam tang chuyen hoa cua hau het TB do do lam tung muc tieu thu oxy dong thoi tang giai phong cac sp chuyen hoa cuoi cung. chinh nhung chat nay co td lam gi•n mach o hau het cac mo trong co the do vay lam tang lg mau dn lg mau den da boi vi co the co nhu cau tang thai nhiet

+ tac dung len nhip tim : tang nhip tim, luu lg tim

+ tac dung len huyet ap

- tac dung len he thong TK co :

+ tac dung len he TK TW : hormon tuyen giap kick thick su phat trien ca ve kick thuoc va ve chuc nang cua n•o

. nhuoc nang tuyen giap gay tinh trang cham chap trong suy nghi, ngu nhieu.

. uu nang tuyen giap lai gay tinh trang cang thang va khuynh huong roi loan tam than nhu lo lang qua muc, hoang tuong, nmet moi kho ngu

+ tac dung len cnang co : lg hormon dc bai tiet nhieu -> co yeu vi tang thoaI hoa pr cua co. Mot khac neu thieu hormon tuyen giap co tro nen cham chap nhat la gi•n ra cham sau khi co

. trong nhung dau hieu dtrung of uu nang tuyen giap la run co (tan so la 10 -15 lan/phut)

- tac dung len co quan sinh duc : can cho su ptrien bthg cua cquan sduc

. o nam gioi, thieu hormon tuyen giap -> gay mat duc tinh hoan toan, nhung neu bai tiet nhieu gay bat luc

. o nu gioi : thieu hormon tuyen giap -> gay bang kinh, da kinh, nhung thua hormon tuyen giap gay it kinh or vo kinh va giam duc tinh.

*) Dieu hoa bai tiet :

- do Cm TSh cua tuyen yen : TSH cua tuyen yen kick thick tuyen giap bai tiet T3, T4 do vay neu TSH tang thi T3, T4 se dc bai tiet nhieu va ngc la neu TSH giam thi T3, T4 se dc bai tiet it

- khi bi lanh or stress Cm T3,T4 se dc bai tiet nhieu

- co che dieu hoa:

+ Cm iod vo co cao trong tuyen giap se uc che bai tiet T3, T4

+ Cm iod huu co cao dan toi giam thu nhan iod va do do lam giam tong hop T3- T4

*) UDLS: