BIOL 1412 Lecture Notes - Threshold Potential, Membrane Potential
4 May 2014
School
Department
Course
Professor
Document Summary
Factors establishing rmp: na+/k+ -atpase (na+/k+ pump) -not a channel. 11. 8) (membrane more permeable to k+ than na+ at rest therefore, k+ is the major determinant of. K+ diffuses out of cell down [ ] gradient therefore, cell losses +ve charge (inside becomes more -ve) Unlike charges attract and k+ diffusion as inside becomes increasingly -ve. Na+ diffusion in increases due to increasing attraction to -ve cell interior. Until -70mv reached, +ve out (k+) is greater than +ve (na+) in greater k+ permeability. Once at -70mv, the amount of +ve (k+) moving out equals the amount of +ve (na+) moving in - force on na+ much higher than on k+ Therefore, the net movement of charge (ions) is 0 (equal in both directions): * capable of producing departures from rmp in response from rmp in response to stimuli (=changes in the external or internal env"t)
