Question: When you touch a warm plate of food being handed around the dinner table, the first type of neuron to be activated is a(n) _____.

Answer: Sensory Neuron. Sensory neurons transmit information about the environment to the brain.

Question: Which structure is not part of a neuron?

Answer: Myelin Sheath. The myelin sheath is the layer of Schwann cells wrapped around a neuron.

Question: Action potentials in a given neuron are propogated _____

Answer: They are propagated down the length of the axon.

Question: Action potentials travel in only one direction down an axon because sodium channels in the neuron are refractory.

Answer: Action potentials travel in only one direction down an axon because sodium channels in the neuron are refractory.

Question: Which event triggers the creation of an action potential?

Answer: The membrane depolarizes above a certain threshold potential. Influx of Na+ ions into the neuron can lead to membrane depolarization above the threshold potential; this event triggers the creation of an action potential.

Question: Which of the following terms describes how a neuronal membrane’s potential is altered in the presence of inhibitory signals?

Answer: Hyperpolarization. Inhibitory signals hyperpolarize the membrane and make the membrane potential even more negative than normal.

Question: Where in the neuron do action potentials begin?

Answer: Axon hillock. The axon hillock is the region where voltage-gated channels begin in a neuron, near the cell body.

Question: How is an action potential propagated down an axon after voltage-gated sodium channels open in a region of the neuron’s membrane?

Answer: Sodium ions enter the neuron and diffuse to adjacent areas, resulting in the opening of voltage-gated sodium channels farther down the axon

Question: How is an action potential propagated down an axon after voltage-gated sodium channels open in a region of the neuron’s membrane?

Answer:

Question: What would occur if sodium channels remained open once membrane depolarization was complete?

Answer: Repolarization would occur, but much more slowly. While sodium ions would continue to move into the cell, potassium moving out would counteract it.