The following statement describes, in random order, events during the transmission of a nerve impulse. Use them to answer the next \g question(s).
Event 1: Positive ions flow into the neuron.
Event 2: The resting potential of the cell membrane is restored.
Event 3: The cell membrane becomes more permeable to Na+ than to K+.
Event 4: More positive ions accumulate on the outside than on the inside of the neuron.
Event 5: The ion pumps transport Na+ out of the neuron and K+ into the neuron.
1. Which order of events first describes the resting membrane and then the sequence of events as a nerve impulse occurs?
A.
To answer the question, we need to determine the correct order of events that describes the resting membrane and the sequence of events during a nerve impulse. Let's analyze the options:
Option A:
1. Event 2: The resting potential of the cell membrane is restored.
2. Event 3: The cell membrane becomes more permeable to Na+ than to K+.
3. Event 1: Positive ions flow into the neuron.
4. Event 5: The ion pumps transport Na+ out of the neuron and K+ into the neuron.
5. Event 4: More positive ions accumulate on the outside than on the inside of the neuron.
To determine if this is the correct order, we can check if it matches the logical flow of events during the transmission of a nerve impulse.
During rest, the cell membrane maintains a resting potential, so Event 2 (resting potential restored) seems to fit as a starting point.
During a nerve impulse, several events occur, but the key factor is the change in permeability to Na+ and K+. This increased permeability allows positive ions (Na+) to flow into the neuron, which corresponds to Event 3 and Event 1.
Following that, the ion pumps work to restore the ion concentration gradients, pumping Na+ out of the neuron and K+ into the neuron. This aligns with Event 5.
Finally, Event 4 states that more positive ions accumulate on the outside than on the inside of the neuron. This occurs as a result of the previous events, so Event 4 seems to fit logically.
Based on this analysis, Option A (2, 3, 1, 5, 4) appears to be the correct order of events that first describes the resting membrane and then the sequence of events during a nerve impulse.