In general, the frequency of APs in an afferent neuron is related to the amplitude of the receptor potential in the following way:
a. exponentially.
b. there is no general relationship.
c. logarithmically.
d. linearly.
Is it exponentially? The other options make no sense.
During the rising phase of the action potential:
a. the membrane potential becomes more negative.
b. the hyperpolarization of the membrane potential brings it to threshold.
c. there is a net influx of Na+.
d. voltage-gated Na+ channels close.
I put there is a net influx of Na+
Both your answers are correct. Great job!
the first one is
b. there is no general relationship.
For the first question, you are correct. The frequency of action potentials (APs) in an afferent neuron is generally related to the amplitude of the receptor potential exponentially. This means that as the amplitude of the receptor potential increases, the frequency of APs also increases at an exponential rate. The other options provided do not accurately describe this relationship.
For the second question, the correct answer is c. There is a net influx of Na+. During the rising phase of the action potential, the membrane potential becomes more positive due to the opening of voltage-gated Na+ channels. This allows Na+ ions to rush into the cell, leading to depolarization and the generation of the action potential. So, the correct answer is that there is a net influx of Na+.
The other options are not accurate. The membrane potential becomes more positive, not more negative. The hyperpolarization of the membrane potential is seen during the repolarization and hyperpolarization phases of the action potential, not the rising phase. Voltage-gated Na+ channels do not close during the rising phase but rather open to allow the influx of Na+ ions.