The all-or-none principle states that
A) all stimuli will produce identical action potentials.
B) all stimuli great enough to bring the membrane to threshold will produce identical action potentials.
C) the greater the magnitude of the stimuli, the greater the magnitude of the action potential.
D) only sensory stimuli can activate action potentials.
E) only motor stimuli can activate action potentials.
Question 2
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
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