click below
click below
Normal Size Small Size show me how
AP in Cardiac Muscle
AP in cardiac muscle cells
| Question | Answer |
|---|---|
| Step 1 - Rapid Depolarization | Threshold. Voltage gated Na channels opne and membrane becomes more permeable to Na. Massive influx of Na and rapid DP of sarcolemma. Channels = Fasr Channels b/c they are only open for a few miliseconds |
| Step 2 - Plateau | transmembrane potential = +30 mv. Voltage regulated Na channels close. Cell pumps out Na out. Slow Ca channels opening. (175 msec open for) Ca enters the sarcoplasm (balances loss of + ions) 0 mv. |
| Step 3 - Repolarization | Slow channels keep closing. Slow K channels closing. K ions rush out of cell rapidl, repolarization restores resting potential. |