Neurons and Synapses - B

Question 1

Define action potential

Answer 1

axons that are able to transmit signals in
the form of electrical impulses.

Question 2

Define depolarization

Answer 2

Na+ channels open,
allowing Na+ to diffuse
inside the neuron. The
Potential becomes +30mV

Question 3

Define Repolarization

Answer 3

Na+ channels close and
K+ channels open. K+
diffuses outwards. The
potential returns to
-70 mV

Question 4

Define Hyperpolarization

Answer 4

The diffusion
of K+ changes the potential from positive to negative, often
overshooting the resting potential.

Question 5

List steps of propagation

Answer 5

The membrane is at resting potential.

An action potential causes Na+ channels to open and Na+ diffuses into the cell. Na+ inside the cell diffuses toward the neighboring region.

When the threshold potential is reached, nearby Na+ channels open, resulting in
depolarization.

K+ ion channels open in the original region, allowing K+ ions to diffuse outward.
This repolarizes the local region, which returns to the resting potential.

This process repeats allowing the action potential to move forward.