Steps of the nerve Impulse

Question 1

What are the 5 steps of an action potential?

Answer 1

1. resting potential
2. threshold
3. action potential
4. depolarization
5. hyperpolarization

Question 2

1. Resting potential
   -what is the mV
   -what is the state of the gates
   -what is the charge of outside and inside

Answer 2

-70
both na and K gates are closed
the inside is negative

Question 3

2. Threshold
   -what does the stimulus trigger
   -what is the mV

Answer 3

-opening of a few non voltage gates (Na+)
(-55mV)

Question 4

3. Action Potential
   -what gate opens
   -what happens to the membranes polarity
   -What is the mV

Answer 4

-voltage gates for Na+
-reversed and therefore depolarized
(35mV)

Question 5

4. Depolarization
   -what does the peaking voltage trigger (2)
   -What else asists in the repolarization process, what does it pump in and out + how many
   -what is the time period known as for repolarization
   -can an impulse be activated during this time?

Answer 5

-the closing of voltage gated Na+ channels and opens up voltage gated k+ channels for k+ to diffuse out of the axon
-Na+/k+ pump will asist by activley pumping out 3Na+ for every 2k+ that enters.
-Refractory period
-no

Question 6

5. Hyperpolarization
   -what is it
   -what does it result from and lead back to

Answer 6

-undershoot of the resting potential
-because K+ channels close slowly and membrane goes back to resting potential