Can anybody explain the reasoning behind this? The passage stated that the SA node has a higher than normal permeability to Na+ and that sodium fluxes in during a cardia action potential through a VG Na+/Ca2+ channel. But my understanding is that both the Na+/Ca2+ exchanger (NCX) and Na/K pump work to restore membrane potential. Normally the NCX pumps 3 Na+ into the cell, down its conc. gradient to pump 1 Ca2+ out of the cell against its conc. gradient. (secondary active transport) where as...
Examkrackers Exam 1 B/B #168
Examkrackers Exam 1 B/B #168