Action potential Flashcards
1
Q
Which ion is most important in repolarization?
A
K+
2
Q
Tetrodotoxin, caine drugs?
Tetraethylammonium?
Ciguatoxin?
A
- Block Na+ channels > No AP
- Blocks K+ channels > long repolarization
- Opens Na+ channels > AP
3
Q
Absolute refractory?
Relative refractory?
A
- All Na+ channels open
- Strong stimulus > AP in hyperpolarization
4
Q
Hyperkalemia?
Hypercalcemia?
A
- Keeps cells depolarized
- Ca2+ block Na+ channels
5
Q
Bigger Tau?
Smaller Tau?
Advantage of larger tau?
A
- Slower change in Vm
- Faster change in Vm
- Can sum Vm to reach threshold
6
Q
Small lambda?
Large lambda?
A
- Current travels shorter distance before losing 63%
- Farther distance
7
Q
Velocity increases if we:
_ diameter
_ capacitance
A
- Increase
- Decrease(myelination)
8
Q
Demyelinating diseases(2)
What does it do?
A
- MS(CNS), Guillain Barre syndrome(PNS)
- Blocks saltatory conduction
