Question 1

Which of the following statements best describes the function of the phrenic nerve?

Accepted Answer

It supplies motor innervation to the diaphragm, enabling breathing.

Question 2

A patient presents with loss of sensation in the lateral forearm and weakness in elbow flexion. Which nerve is most likely affected?

Accepted Answer

Musculocutaneous nerve

Question 3

Which structure is responsible for myelination of axons in the peripheral nervous system?

Accepted Answer

Schwann cell

Question 4

The area of skin innervated by a single spinal nerve is called a:

Accepted Answer

Dermatome

Question 5

Which nerve arises from the lumbar plexus and is responsible for innervating the quadriceps femoris muscle?

Accepted Answer

Femoral nerve

Question 6

If the radial nerve is damaged at the mid-humerus, which clinical sign is most likely to be observed?

Accepted Answer

Loss of wrist extension (wrist drop)

Question 7

Which of the following cranial nerves is a good example of a bipolar neuron?

Accepted Answer

Olfactory nerve (CN I)

Question 8

The brachial plexus is formed by the ventral rami of which spinal nerve roots?

Accepted Answer

C5-T1

Question 9

Which nerve is responsible for innervating most of the intrinsic muscles of the hand?

Accepted Answer

Ulnar nerve

Question 10

A lesion affecting the dorsal root of a spinal nerve would most likely result in:

Accepted Answer

Loss of sensory function only

Question 11

Which equation best represents the relationship between the number of spinal nerves and spinal segments?

Accepted Answer

$$N_{spinal\ nerves} = N_{spinal\ segments}$$

Question 12

Which nerve is most likely to be injured in a fracture of the surgical neck of the humerus?

Accepted Answer

Axillary nerve

Question 13

Which of the following best describes the role of the ventral rami?

Accepted Answer

They supply the main components of the trunk and limbs.

Question 14

A patient has difficulty adducting their thigh. Which nerve is most likely affected?

Accepted Answer

Obturator nerve

Question 15

Which nerve is responsible for innervating the triceps brachii muscle?

Accepted Answer

Radial nerve

Question 16

Which of the following is TRUE regarding Schwann cells?

Accepted Answer

They myelinate axons in the peripheral nervous system.

Question 17

Which nerve is most likely to be injured in a patient who cannot dorsiflex their foot?

Accepted Answer

Common fibular (peroneal) nerve

Question 18

Which of the following nerves is NOT derived from the brachial plexus?

Accepted Answer

Femoral nerve

Question 19

A patient presents with numbness in the medial aspect of the hand and difficulty with finger abduction. Which nerve is most likely affected?

Accepted Answer

Ulnar nerve

Question 20

Which equation best describes the relationship between the number of cranial nerves and their pairs?

Accepted Answer

$$N_{cranial\ nerves} = 12$$

Peripheral Nervous System: Nerve Plexuses, Branches, and Skeletal Muscle Innervations

Study Guide - Practice Questions