BIOL 3060 Lecture Notes - Lecture 12: Pacemaker Current, Threshold Voltage, Reversal Potential
Document Summary
Nov 1: the body decides what the heart needs to through the brain, hcn funny current channels, stuck open but close during depolarization. This channel is turned on at negative potential. At the same time, the ikach (k channel, its reversal potential is about -85mv), it is open only when ach (its ligand) is present (pns is on all the time, so it is a fixed current). If channels are regulated by camp, and ikach channels are regulated by ach: ca channels: two types, t type ca current: transient, similar to na channels, they activate with depolarization and inactivate. They open at the same range of membrane potential as na channel (- = modified na channel, one amino acid difference. During the depolarizing potential when the t type channel opens, it accelerates the membrane towards the threshold, by bringing ca into the cell.
