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KIN 205: Chapter 14, Cardiovascular Physiology:
-60
-40
Phase 1:
The first phase of depolarization is
due to the entry of Na
+
and exit of K
+
via
channels that are permeable to both Na
+
and
K
+
. At -60 mV, the influx of Na
+
exceeds the
outflux of K
+
and the cell depolarizes.
Phase 2:
As the cell depolarizes, the
channels that are permeable to Na
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Unformatted text preview: + and K + close and there is opening of voltage-gated Ca 2+ channels that lead to influx of Ca 2+ and further depolarization. Phase 3: At the peak of the action potential, the Ca 2+ channels close and K + channels open. Phase 4: The repolarization is due to an efflux of K + . At -60mV, the K + channels are closed....
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- Fall '09
- Blaber
- The Canon of Medicine, K+ channels, Cardiovascular Physiology
-
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