Question 1

Which of the following best describes the function of the enteric nervous system (ENS)?

Accepted Answer

It initiates and coordinates visceral reflexes locally within the digestive tract, often without instructions from the CNS.

Question 2

A neuron receives simultaneous excitatory and inhibitory inputs. Which process determines whether an action potential will be generated?

Accepted Answer

Summation of EPSPs and IPSPs at the axon hillock.

Question 3

Which equation represents the equilibrium potential for potassium ($$K^+) $$ions across the neuronal membrane, using the Nernst equation?

Accepted Answer

$$E_{K^+} = \frac{RT}{zF} \ln \left( \frac{[K^+]_{out}}{[K^+]_{in}} \right) $$

Question 4

During the generation of an action potential, what is the primary cause of depolarization?

Accepted Answer

Influx of $$Na^+$$ ions through voltage-gated channels.

Question 5

Which neuroglial cell is responsible for maintaining the blood-brain barrier (BBB) in the CNS?

Accepted Answer

Astrocytes

Question 6

A patient suffers a spinal cord injury. Why is nerve regeneration in the CNS limited compared to the PNS?

Accepted Answer

Astrocytes produce scar tissue and release chemicals that block regrowth.

Question 7

Which of the following best explains why myelinated axons conduct action potentials faster than unmyelinated axons?

Accepted Answer

Myelin allows saltatory propagation, enabling the action potential to jump from node to node.

Question 8

Which neurotransmitter is released at all neuromuscular junctions involving skeletal muscle fibers?

Accepted Answer

Acetylcholine (ACh)

Question 9

A neuron is exposed to a chemical that opens potassium ion channels. What is the expected effect on the membrane potential?

Accepted Answer

Hyperpolarization, as positive ions move out of the cell.

Question 10

Which of the following is TRUE regarding the sodium-potassium exchange pump?

Accepted Answer

It uses one ATP to eject 3 $$Na^+$$ ions for every 2 $$K^+$$ ions brought in.

Question 11

Which type of neuron is most commonly found in the CNS and is responsible for higher functions such as memory, planning, and learning?

Accepted Answer

Interneurons

Question 12

Which of the following best describes temporal summation?

Accepted Answer

Rapid, repeated stimuli at a single synapse that combine to produce a greater effect.

Question 13

Which of the following is a direct effect of neurotransmitters on the postsynaptic membrane?

Accepted Answer

Opening or closing chemically gated ion channels.

Question 14

Which equation best represents Ohm's Law as applied to the neuronal membrane?

Accepted Answer

$$I = \frac{V}{R} $$

Question 15

Which of the following statements about the refractory period is correct?

Accepted Answer

During the absolute refractory period, the membrane cannot respond to further stimulation.

Question 16

Which type of axon transmits information most rapidly to and from the CNS?

Accepted Answer

Type A fibers

Question 17

A patient is experiencing synaptic fatigue. What is the most likely cause?

Accepted Answer

Neurotransmitter cannot be recycled fast enough to meet demands of intense stimuli.

Question 18

Which of the following is TRUE regarding the effect of neurotransmitters?

Accepted Answer

The effect depends on the properties of the receptor, not the nature of the neurotransmitter.

Question 19

Which of the following best describes the function of microglia in the CNS?

Accepted Answer

They migrate through nervous tissue and clean up cellular debris, wastes, and pathogens.

Question 20

Which of the following is a characteristic of graded potentials?

Accepted Answer

The change in membrane potential is proportional to the strength of the stimulus and decreases with distance from the site of stimulation.

Nervous Tissue: Structure, Function, and Information Processing

Study Guide - Practice Questions