- Joined
- Jul 25, 2014
- Messages
- 125
- Reaction score
- 154
So currently studying cardiology and I am flustered.....The funny current, Phase 4 (slow depolarization) in pacemaker cells I thought occurred solely due the influx of Na+, but UWorld and other sources say its due to the influx of BOTH Na+ and K+. Which one is it? Why would K+want to flow into the cell when Na+/K+ATPase is establishing a gradient that favors otherwise (high K+ concentration intracellular which actually causes a K+ efflux in other cardiac myocytes during phase 4). Also woudnt that cause a rapid accumulation of K+ within the cell? Please help