Question 1

Which neuroglial cell is found exclusively in the CNS and is primarily responsible for forming the myelin sheath around axons?

Accepted Answer

Oligodendrocyte

Question 2

A patient suffers a spinal cord injury that damages the anterior gray horn. Which function is most likely to be impaired?

Accepted Answer

Initiating voluntary motor commands

Question 3

Which equation best represents the calculation of the resting membrane potential ($$RMP) in $$neurons?

Accepted Answer

$$RMP = \frac{RT}{F} \ln \left( \frac{[K^+]_{out} + [Na^+]_{out} + [Cl^-]_{in}}{[K^+]_{in} + [Na^+]_{in} + [Cl^-]_{out}} \right)$$

Question 4

During saltatory conduction, how does the action potential propagate along a myelinated axon?

Accepted Answer

It jumps from one node of Ranvier to the next.

Question 5

Which structure in a neuron is responsible for receiving synaptic inputs and generating graded potentials?

Accepted Answer

Dendrite

Question 6

A patient exhibits a positive Babinski sign during a neurological exam. What does this indicate about their nerve pathway?

Accepted Answer

Damage to the upper motor neuron pathway

Question 7

Which of the following best describes the function of the phrenic nerve, which arises from the cervical plexus?

Accepted Answer

Innervates the diaphragm for breathing

Question 8

Which of the following is a key difference between myelin in the CNS and myelin in the PNS?

Accepted Answer

CNS myelin is produced by oligodendrocytes, while PNS myelin is produced by Schwann cells.

Question 9

Which of the following best explains why spinal nerves are classified as mixed nerves?

Accepted Answer

They contain both sensory and motor fibers.

Question 10

A withdrawal reflex is triggered when you touch a hot stove. Which sequence correctly describes the components of the reflex arc?

Accepted Answer

Receptor → Sensory neuron → Interneuron → Motor neuron → Effector

Question 11

Which of the following best describes the function of the gray commissure in the spinal cord?

Accepted Answer

Connects the left and right sides of the spinal cord gray matter

Question 12

Which of the following is TRUE regarding the function of voltage-gated sodium ($$Na^+) $$and potassium ($$K^+) $$channels during an action potential?

Accepted Answer

Voltage-gated $$Na^+$$ channels open during depolarization, and voltage-gated $$K^+$$ channels open during repolarization.

Question 13

Which of the following best describes the role of a muscle spindle in a stretch reflex?

Accepted Answer

Detects changes in muscle length and initiates a reflex contraction

Question 14

Which of the following is a function of the posterior gray horn in the spinal cord?

Accepted Answer

Processes sensory information

Question 15

Which scenario best illustrates temporal summation at a chemical synapse?

Accepted Answer

A single presynaptic neuron releases neurotransmitter repeatedly in rapid succession onto a postsynaptic neuron.

Question 16

Which of the following best describes the function of the white matter tracts in the spinal cord?

Accepted Answer

Transmit information up and down the spinal cord

Question 17

Which of the following is a characteristic of a monosynaptic reflex?

Accepted Answer

Involves only one synapse between a sensory neuron and a motor neuron

Question 18

Which equation represents the Nernst equation for calculating the equilibrium potential ($$E_{ion}) $$for a given ion?

Accepted Answer

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

Question 19

Which of the following best describes the function of an interneuron in a spinal reflex?

Accepted Answer

Integrates and relays information between sensory and motor neurons

Question 20

A patient is unable to regenerate damaged axons in the CNS, but can do so in the PNS. Which factor best explains this difference?

Accepted Answer

Presence of Schwann cells in the PNS that promote axon regeneration

Neural Tissue, Neurophysiology, and Spinal Cord: Study Guide for Exam #3

Study Guide - Practice Questions