Mechanisms and Mgmt of Pain Midterm

October 23, 2025

What factor increases action potential conduction velocity in axons?

a) smaller axon diameter

b) higher membrane capacitance

c) increased membrane resistance from myelination

d) fewer voltage-gated ion channels at the nodes of Ranvier

c) increased membrane resistance from myelination

 

Local anesthetics such as lidocaine prevent the sensation of pain primarily by:

a) blocking K⁺ channels and preventing repolarization

b) blocking Na⁺ channels and preventing action potential initiation

c) increasing membrane capacitance to slow depolarization 

d) decreasing membrane resistance to prevent conduction

b) blocking Na⁺ channels and preventing action potential initiation

Which statement about myelination is correct?

a) myelin decreases conduction velocity by increasing axial resistance

b) myelin increases conduction velocity by increasing membrane capacitance

c) myelin increases conduction velocity by increasing membrane resistance and decreasing capacitance

d) myelin has no effect on conduction velocity

c) myelin increases conduction velocity by increasing membrane resistance and decreasing capacitance

Which of the following best defines afferent signaling?

 

a) Transmission of motor commands from the CNS to muscles

b) Process of carrying sensory information toward the CNS

c) Reflexive inhibition of pain signals in the spinal cord

d) Transmission of autonomic signals from the CNS to viscera

b) Process of carrying sensory information toward the CNS

The cell bodies of first-order sensory neurons are typically located in:

a) Ventral horn of the spinal cord

b) Dorsal root ganglia or cranial sensory ganglia 

c) Primary somatosensory cortex

d) Brainstem nuclei only

b) Dorsal root ganglia or cranial sensory ganglia 

Which type of sensory receptor is primarily responsible for detecting noxious mechanical, thermal, or chemical stimuli?

 

a) Mechanoreceptors

b) Thermoreceptors

c) Nociceptors

d) Chemoreceptors

c) Nociceptors

T/F: Decussation refers to the way that axons cross to the opposite side of the spinal cord or brain.

True

Name the major ascending pain pathway that transmits the pain of stepping on a nail:

a) Dorsal Column Medial Lemniscus Tract

b) Reticulobulbar Tract

c) Corticospinal Tract

d) Spinothalamic Tract

d) Spinothalamic Tract

Which of the following best describes an interneuron?

 

a) An interneuron is a large neuron that sends axons to other interconnected regions of the brain

b) An interneuron is a smaller neuron that connects neurons within that region of the nervous system

c) An interneuron is only found outside of the CNS, within internal organs

b) An interneuron is a smaller neuron that connects neurons within that region of the nervous system

Which of the following statements is true?

1. Descending signals from the brain to the spinal cord can amplify nociceptive signals.

2. Descending signals from the brain to the spinal cord can decrease transmission of nociceptive signals.

3. Mechanoreceptors can decrease transmission of nociceptive signals.

 

a) only 1

b) only 2

c) only 3

d) Both 1 and 2

e) 1, 2, and 3

e) 1, 2, and 3

Which of the following is true concerning chronic pain?

 

a) Nociceptors tend to become less excitable and transmit fewer pain signals

b) Chronic pain only occurs if a severe injury failed to heal properly

c) The severity of chronic pain can differ between two individuals with the same injury or condition

d) CNS is the only part of the nervous system that undergoes sensitization in chronic pain conditions

e) All of the above statements are false

c) The severity of chronic pain can differ between two individuals with the same injury or condition

Select the best answer to this question: Which of the following factors released in peripheral tissues can play a role in sensitizing primary afferents?

a) Nerve Growth Factor 

b) Prostaglandin

c) Histamine

d) All of the above

d) All of the above

Which statement best describes pain perception?

 

a) Pain can be directly measured by recording nociceptor activity.

b) Pain is purely an objective process independent of consciousness.

c) Pain has a neural basis but is ultimately a subjective perception.

d) Pain only occurs when nociceptors are activated.

c) Pain has a neural basis but is ultimately a subjective perception.

Which processes can be measured objectively in pain research?

 

a) Transduction, transmission, and perception 

b) Transmission, perception, and modulation

c) Transduction, transmission, and modulation

d) Perception, modulation, and awareness

c) Transduction, transmission, and modulation

Which structure plays a central role in linking pain with fear and anxiety, contributing to chronic pain?

 

a) Hippocampus

b) Amygdala

c) Thalamus

d) Prefrontal cortex

b) Amygdala

Which statement best defines a neurotransmitter?

 

a) A hormone released into the bloodstream to act on distant organs

b) A chemical messenger that transmits signals across a synapse to a target cell

c) A molecule that only inhibits neuronal firing

d) A structural component of the neuronal membrane

b) A chemical messenger that transmits signals across a synapse to a target cell

Which neurotransmitter is the primary excitatory neurotransmitter in the CNS?

 

a) Glycine 

b) GABA

c) Glutamate 

d) Dopamine

c) Glutamate

What determines whether a neurotransmitter’s effect is excitatory or inhibitory?

 

a) Its molecular size

b) The type of receptor it binds to 

c) The amount of neurotransmitter released 

d) Its rate of enzymatic degradation

b) The type of receptor it binds to 

What is the primary clinical risk associated with high-dose opioid administration?

 

a) Hypertension

b) Hyperventilation

c) Respiratory arrest

d) Seizure

c) Respiratory arrest

What type of receptor are opioid receptors?

a) Ionotropic

b) Tyrosine kinase

c) Ligand-gated chloride channel

d) G-protein coupled

d) G-protein coupled

Which of the following is an endogenous opioid peptide?

 

a) Fentanyl

b) Endorphin

c) Morphine

d) Tramadol

b) Endorphin