Question

38. Which contributes to the resting membrane potential? A) the Na /K Pump removes 3 Na for every 2 K brought in B) ion channels constantly leak potassium out of the cell C) anions on the inside of the membrane cannot leave the cell D) all the above

Answer 1

The resting membrane potential is a result of the Na+/K+ pump removing more positive ions from the inside of the cell than it brings in, the leakage of potassium ions out of the cell, and the presence of impermeable anions inside the cell. The combined effect of all these factors maintains a typical -70 mV potential inside neurons, making the correct answer 'D) all the above'.

Step-by-step explanation:

The factors that contribute to the resting membrane potential include:

• The Na+/K+ pump which removes 3 Na+ ions for every 2 K+ ions it brings in, creating a net loss of positive charge inside the cell, thus contributing to the negative resting potential.
• Potassium ion channels that constantly leak potassium (K+) out of the cell, which increases the negative charge inside due to the loss of positive ions.
• Impermeable anions inside the cell membrane which contribute to the overall negative charge since they cannot leave the cell.

Each of these elements is crucial in the development and maintenance of the typical -70 mV resting membrane potential in neurons. Therefore, the correct answer to which contributes to the resting membrane potential is D) all the above.