$$\text{Stimulus} \rightarrow \text{Response} \rightarrow \text{Restoration of original condition}$$

Question 1

Which of the following best describes the relationship between the central nervous system (CNS) and the peripheral nervous system (PNS)?

Accepted Answer

The CNS and PNS are continuous both anatomically and functionally, with many PNS neuron cell bodies residing in the CNS.

Question 2

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

Accepted Answer

Musculocutaneous nerve

Question 3

Which cranial nerve is responsible for transmitting sensory information related to vision?

Accepted Answer

Optic nerve (II)

Question 4

Which of the following best explains why damage to an entire peripheral nerve is more dangerous than damage to a single neuron?

Accepted Answer

A nerve contains axons from multiple sensory and motor neurons, so damage affects multiple functions.

Question 5

Which of the following is TRUE regarding the brachial plexus and its major nerves?

Accepted Answer

The ulnar nerve supplies most of the intrinsic hand muscles and the skin of the fifth digit.

Question 6

A patient is unable to extend their knee and has lost sensation over the anterior thigh. Which nerve is most likely damaged?

Accepted Answer

Femoral nerve

Question 7

Which of the following best describes the function of mechanoreceptors?

Accepted Answer

They depolarize in response to mechanical deformation such as touch, vibration, stretch, and pressure.

Question 8

Which type of sensory receptor is primarily responsible for detecting painful stimuli?

Accepted Answer

Nociceptors

Question 9

A patient with diabetes mellitus develops burning and shooting pain in their feet. Which type of peripheral neuropathy is most likely responsible?

Accepted Answer

Sensory peripheral neuropathy affecting somatic sensory neurons

Question 10

Which of the following best describes the process of sensory transduction in a somatic sensory neuron?

Accepted Answer

Mechanically gated sodium ion channels open in response to a stimulus, generating a receptor potential.

Question 11

Which equation best represents the threshold for action potential generation during sensory transduction?

Accepted Answer

$$V_{m} \geq V_{threshold}$$

Question 12

Which of the following is TRUE regarding the classification of sensory neurons based on conduction speed?

Accepted Answer

Axons with the largest diameter and thickest myelin conduct impulses the fastest.

Question 13

A patient experiences referred pain in the left arm during a heart attack. Which concept explains this phenomenon?

Accepted Answer

Dermatomes

Question 14

Which of the following best describes the function of muscle spindles?

Accepted Answer

They monitor muscle length and trigger contraction to prevent overstretching.

Question 15

Which reflex is characterized by a monosynaptic arc that returns a stretched muscle to its optimal length?

Accepted Answer

Simple stretch reflex

Question 16

Which equation best represents the negative feedback loop in a simple stretch reflex?

Accepted Answer

$$	ext{Stimulus} ightarrow 	ext{Response} ightarrow 	ext{Restoration of original condition}$$

Question 17

A patient drops a heavy weight after experiencing sudden muscle relaxation. Which reflex is responsible?

Accepted Answer

Golgi tendon reflex

Question 18

Which of the following is TRUE regarding lower motor neuron disorders?

Accepted Answer

They cause muscle paralysis and loss of stretch reflexes.

Question 19

Which sign is characteristic of upper motor neuron disorders and can be tested by stroking the bottom of the foot?

Accepted Answer

Babinski sign

Question 20

Which cranial nerve reflex involves the trigeminal nerve as the afferent limb and results in blinking when the cornea is touched?

Accepted Answer

Corneal blink reflex

The Peripheral Nervous System: Structure, Function, and Clinical Relevance

Study Guide - Practice Questions