Concept explainers
What happens when a resting neuron's membrane depolarizes?
- A. There is a net diffusion of Na+ out of the cell.
- B. The equilibrium potential for K+ (EK) becomes more positive.
- C. The neuron’s membrane voltage becomes more positive.
- D. The cell’s inside is more negative than the outside.
Introduction:
In neuronal signaling, the ions have an important role. Like rest of the cells, the ions are also unequally distributed in the neurons. They are distributed unequally between the surrounding fluid and the cells interior region. Thus, membrane potential means the difference in voltage or charge across a plasma membrane. In case of the resting nerve; the one that does not send signals, the membrane potential is known as the resting potential.
Answer to Problem 1TYU
Correct answer:
When the resting neuron’s membrane depolarizes, the voltage of the neuron’s membrane becomes more positive. Therefore, option (C) is correct.
Explanation of Solution
Reason for the correct statement:
Na+ (sodium) and K+ (potassium) ions are very important for forming the resting potential. When depolarization occurs, there is inflow of Na+, which makes the interior more positive.
Option (C) is given as “The neuron’s membrane voltage becomes more positive”.
“When the resting neuron’s membrane depolarizes, the voltage of the neuron’s membrane becomes more positive”, it is the right answer.
Hence, option (C) is correct.
Reasons for the incorrect statements:
Option (A) is given as “There is a net diffusion of Na+ out of the cell”.
During depolarization, the sodium ions move in the cells not outside the cells. So, it is a wrong answer.
Option (B) is given as “The equilibrium potential for K+ (Ek) becomes more positive”.
During depolarization, the equilibrium potential for K+ is negative. So, it is a wrong answer.
Option (D) is given as “The cell’s inside is more negative than the outside”.
During depolarization, the cells interior is more positive. So, it is a wrong answer.
Hence, options (A), (B), and (D) are incorrect.
When the resting neuron’s membrane depolarizes, the voltage of the neuron’s membrane becomes more positive.
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