Exam 19: Nerve Signaling

Explain a way that the nerve cell is able to respond to stimuli of different strengths.

Excitatory neurotransmitters are most likely to:

Local potentials usually occur in the dendrite or soma of the neuron.

During a relative refractory period:

The fastest nerve fibers in the body can conduct an impulse that is how much faster than the slowest fibers in the body?

When a neuropeptide is secreted with one or two other neurotransmitters, it is thought to serve as a neuromodulator, regulating the effects of the other neurotransmitters.

The sensory fibers from the skin generally conduct impulses up to about 130 meters per second.

Many biologists believe that amino acids are among the most common neurotransmitters in the CNS.

Dopamine, epinephrine, and norepinephrine are classified as:

When a neuron is resting, its membrane potential is zero.

The depolarization of a neuron is caused by the influx of the positively charged sodium ion into the cell.

Explain the two types of refractory periods. Explain how the relative refractory period can help determine the strength of the stimulus.

Which is true of a neuron with a resting potential?

The cell will send an impulse during the relative refractory period as long as the stimulus is below threshold.

Which of the following is true of spatial summation?

No impulse can be sent through a neuron:

During the nerve impulse, the internal charge of the neuron becomes briefly positive.

A resting neuron has a positive internal charge.

Stimulus-gated channels open in response to:

Explain the process of an action potential moving down a neuron.