Question 1

Which statement best describes a dermatome?

Accepted Answer

A bilateral area of skin supplied by sensory fibers of a pair of spinal nerves.

Question 2

A patient presents with a rash and blisters along a single dermatome on the torso. Which virus is most likely responsible for this presentation?

Accepted Answer

Varicella-zoster virus (VZV)

Question 3

Which nerve plexus is responsible for innervating the diaphragm?

Accepted Answer

Cervical plexus

Question 4

Why do neighboring dermatomes overlap?

Accepted Answer

To allow for redundancy in sensory coverage in case of nerve injury.

Question 5

Which of the following is TRUE regarding nerve regeneration in the peripheral nervous system (PNS)?

Accepted Answer

Schwann cells help guide axonal regrowth and form new myelin sheaths.

Question 6

A patient suffers an injury to the left brachial plexus. What is the most likely outcome?

Accepted Answer

A portion of the left limb will suffer reduced function.

Question 7

Which equation best represents the process of action potential generation in a monosynaptic reflex arc?

Accepted Answer

$$V_{m} = V_{rest} + \Delta V_{EPSP}$$

Question 8

Which of the following is a property unique to polysynaptic reflexes?

Accepted Answer

They can produce coordinated, controlled responses involving multiple muscle groups.

Question 9

Which nerve is the largest and thickest in the body, and what does it innervate?

Accepted Answer

Sciatic nerve; innervates the hamstring muscles and most of the leg and foot.

Question 10

Which neurotransmitters are major effectors in the autonomic nervous system (ANS)?

Accepted Answer

Acetylcholine and norepinephrine

Question 11

What is the primary difference between the somatic and autonomic nervous systems?

Accepted Answer

The somatic system can only stimulate effectors, while the autonomic system can stimulate or inhibit effectors.

Question 12

Which of the following best describes the withdrawal reflex?

Accepted Answer

A polysynaptic reflex that removes a body part from a painful stimulus.

Question 13

Which equation represents Ohm’s Law as applied to nerve conduction?

Accepted Answer

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

Question 14

Which of the following is NOT a limiting factor for nerve repair in the central nervous system (CNS)?

Accepted Answer

Schwann cells promote axonal regrowth.

Question 15

Which of the following best explains why the effect of a neurotransmitter in the ANS depends on its receptor?

Accepted Answer

The same neurotransmitter can cause different effects depending on the receptor subtype present on the effector cell.

Question 16

Which of the following is a learned reflex?

Accepted Answer

Lifting your foot and leg after stepping on a rock

Question 17

Which equation best represents the relationship between the number of synapses and response time in a reflex arc?

Accepted Answer

$$t_{response} \propto n_{synapses}$$

Question 18

Which of the following is TRUE about the organization of spinal nerves?

Accepted Answer

The dorsal ramus innervates muscles and joints of the back.

Question 19

Which process is described by the degeneration of axon components and myelin sheaths distal to an injury site?

Accepted Answer

Wallerian degeneration

Question 20

Which of the following is a function of Schwann cells during peripheral nerve repair?

Accepted Answer

Releasing growth factors and expressing adhesion molecules to guide axon regeneration

Spinal Nerves, Nerve Plexuses, Dermatomes, and Reflexes – Study Notes

Study Guide - Practice Questions