Multiple Choice
Which term best describes a specialized cell that transmits nerve impulses between the brain and the body?
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45. Nervous System
Neurons and Action Potentials
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Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
The resting membrane potential of neurons is determined by __________.
A
the amount of neurotransmitter released at the synapse
B
the frequency of action potentials generated by the neuron
C
the presence of myelin sheaths around the axon
D
the differential distribution of ions, especially K$^+$ and Na$^+$, across the plasma membrane
Verified step by step guidance1
Understand that the resting membrane potential refers to the electrical charge difference across the plasma membrane of a neuron when it is not actively transmitting signals.
Recognize that this potential is primarily determined by the differential distribution of ions, especially potassium (K⁺) and sodium (Na⁺), across the plasma membrane.
Learn that ion distribution is maintained by the sodium-potassium pump, which actively transports 3 Na⁺ ions out of the cell and 2 K⁺ ions into the cell, creating a concentration gradient.
Note that potassium ions (K⁺) tend to move out of the cell through leak channels due to their higher intracellular concentration, while sodium ions (Na⁺) have limited movement into the cell due to fewer leak channels.
Understand that the selective permeability of the membrane to K⁺ and Na⁺, combined with the activity of the sodium-potassium pump, establishes the resting membrane potential, typically around -70 mV in neurons.
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