Membrane Potential and Action Potentials

Question 1

how is an action potential initiated?

Answer 1

depolarization signal makes it to the axon hillock

Question 2

what is the first step in an action potential?

Answer 2

depolarization - Na+ rushing into the cell – making it less negative

Question 3

what is the second step of an action potential?

Answer 3

repolarization - K+ moves out of the cell – makes it more negative

Question 4

what is hyperpolarization?

Answer 4

the cell is becoming more negative due to the excess outflow of K+

Question 5

what happens to a cell membrane potential when K+ levels are high in the bloodstream?

Answer 5

increase the chance of activation - less negative

Question 6

what is myelin and how does it speed up conduction down an axon?

Answer 6

insulates the neuron and allows for less resistance for ions to flow

Question 7

what parts of the brain and spinal cord are myelinated?

Answer 7

white matter is myelinated