 | Term | Definition |
| |
Phase 1 |
Normal Em for a frog skeletal muscle. Value = -100mV |
| |
Phase 2 |
Cl- efflux depolarizes cell (makes it less negative). K+ efflux due to depolarization. Value= -75mV |
| |
Phase 3 |
KCl leaves cell, so water foloows osmotically. |
| |
Phase 4 |
Em returns to normal value after 16mins. K+ gradient is restored |
| |
Phase 5 |
Cl- re-enters, as do K+ and water, to restore normality. Value falls to -110 mV. |
| |
Phase 6 |
Back to normal Em. Value = -100mV after 30 mins |
| |
Connection Between Em and Cl- |
Em sets the Cl- gradient rather than the Cl- gradient setting Em (like K+) |
| |
Cl- is in equilibrium with Em |
True. |
| |
High permeability of Cl- |
True |
| |
What advantage does high pCl- have |
Membrane stability. It allows the membrane potential to return to normal. |
| |
What porblems could arise with altered pCl- |
Congenital reduction in pCl- produces spontaneous firing and contaction of muscle. MYOTONIA |
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