Cau 7:

Phan ung co than kinh doi voi cac kich thich dien

nguon kich thich - cuong do kich thich:

nguon kich thich: cac yeu to co, dien, nhiet, hoa. Do nhay cam cua cac tb doi voi moi loai kich thich mot khac

trong tn co va than kinh nahy cam nhat voi cac kich thich dien. Cac tb chi bi kich thich khi dien ap tdung len chung co bie do bien doi theo tgian.

Cac kich thich dien dc dac trung boi 2 thong so: cuong do va thoi gian ma kich thich ton tai.

+ neu cuong do kich thich nho, tgian ton tai xd, pu cua co va tk chi xh tai cho dat dien cuc.do la pu tai cho.

+ neu kich thich co cuong do du lon vuot wa nguong kich thich thi no tao dc tren co va tk trang thai hung phan bieu hien bang 1 dien the hd, dc lan di doc cac to chuc dan truyen va co bien do ko doi trong suot wa trinh lan truyen.

wan he cuong do va tgian kich thich

nguong tgian C: la khoang tgian ngan nhat ma xung dien phai keo dai de co the gay hung phan tren tb. Neu tgian keo dai cua xung dien ngan hon C thi xung dien du co cuong do lon den dau cung ko co knang gay nen trang thai hung phan cua tk hay co.

nguong kich thich hay reobazo ki hieu la B: la cuong do nho nhat ma xung kich phai dat dc de gay hung phan

Cronacxi: la khoang tgian ngan nhat ma 1 xung dien co cuong do gap 2 lan nguong kich thich can phai keo dai de gay nen hung phan

Hop cac kich thich con goi la hien tuong cong tac dung cua 2 kich thich duoi nguong

Thoi gian u, giai doan tro: dac tinh cua co va tk la khi bi kich thich chung ko pu vngay lap tuc ma chi sau do 1 tgian.khoang tgian tinh tu diem nhan xung kich thich cho toi diem bat dau xh dien the hd goi la thoi gian u. moi loai tb co 1 tgian u khac nhau.sau gd kich thich la den gd tro.