The following are the main steps in the generation of an action potential.
1) Sodium channels are inactivated.
2) Voltage-gated potassium channels open and potassium moves out of the cell, initiating repolarization.
3) Sodium channels regain their normal properties.
4) A graded depolarization brings an area of an excitable membrane to threshold.
5) A temporary hyperpolarization occurs.
6) Sodium channel activation occurs.
7) Sodium ions enter the cell and depolarization occurs.
What is the proper sequence of these events?
A) 4, 6, 7, 3, 2, 5, 1
B) 4, 6, 7, 1, 2, 3, 5
C) 6, 7, 4, 1, 2, 3, 5
D) 2, 4, 6, 7, 1, 3, 5
E) 4, 2, 5, 6, 7, 3, 1

Question

Quizplus · Accepted Answer

The proper sequence of events in the generation of an action potential is:
1) A graded depolarization brings an area of an excitable membrane to threshold (4).
2) Sodium channel activation occurs (6).
3) Sodium ions enter the cell and depolarization occurs (7).
4) Sodium channels regain their normal properties (1).
5) Voltage-gated potassium channels open and potassium moves out of the cell, initiating repolarization (2).
6) A temporary hyperpolarization occurs (5).
7) Sodium channels are inactivated (3).
Therefore, the correct sequence is 4, 6, 7, 1, 2, 3, 5, which corresponds to option B.

The Following Are the Main Steps in the Generation of an Action