1|P a g e
NU 545 UNIT 2 ACTUAL 2026 EXAM |100
QUESTIONS AND CORRECT DETAILED
ANSWERS | RATED A+ | NEW AND
REVISED
Where in the CNS does pain perception occur? - ANSWER- Pain
perception occurs primarily in the reticular and limbic systems and the
cerebral cortex (p476)
It is the conscious awareness of pain; requires the interaction of three
systems:
1. Sensory-discriminative system
Mediated by: the somatosensory cortex
Responsibility: identifying the presence, character, location and intensity
of pain
2. Affective-motivational system
Mediated by: reticular formation, limbic system, and brainstem with
projections to the prefrontal cortex
Responsibility: individual conditioned avoidance behaviors and
emotional responses to pain
3. Cognitive-evaluative system
Mediated by: cerebral cortex
Responsibility: overlies individual's learned behavior concerning the
experience of pain and can modulate perception of pain
,2|P a g e
Know different clinical descriptions of pain (acute, chronic,
neuropathic); pain threshold/tolerance - ANSWER- 1. Neurophysiologic
Pain
2. Neurogenic Pain
3. Temporal Pain (time related, duration)
4. Pain Location
5. Etiologic Pain
(p480)
signal to the person of a harmful stimulus
· Normal & protective; lasts only seconds to days (up to 3 months)
· Begins suddenly and is relieved after stimulus is removed.
· Clinical signs are related to ANS: ↑HR, HTN, diaphoresis, dilated
pupils (476) (481)
Pain threshold & tolerance are subjective phenomena influence an
individual's perception of pain. Can be influenced by gender, culture,
expectations, role behaviors, physical/mental health, age, fatigue, anger,
boredom, apprehension, and sleep deprivation (Page 471)
Pain threshold: lowest intensity of pain a person can recognize. Different
areas of the body have different thresholds
Pain tolerance is the greatest intensity of pain that a person can endure
(p476)
Know endogenous opioids - ANSWER- A family of morphine-like
neuropeptides that inhibit transmission of pain impulses in the periphery,
spinal cord, and brain by binding with specific opioid receptors (mu,
,3|P a g e
kappa, delta). They inhibit ion channels, preventing the release of
excitatory neurotransmitters, such as substance P and glutamate, in the
dorsal horn (p478)
In the midbrain, they influence descending inhibitory pathways
· In peripheral inflamed tissue, opioids are produced and released from
leukocytes to activate opioid receptors on sensory nerve terminals. They
cannot cross the blood-brain barrier - this means they do not cause CNS
side effects like drowsiness, ↓respirations, or addiction
· Found in almost all tissues in the body. In addition to analgesia,
endogenous opioids are involved in a variety of other functions in the
body including modulating stress/anxiety, feeding behavior, cough
suppression, immune/inflammatory responses, and alcohol intak
Dynorphins for substance abuse and kappa receptors. (p479)
What are the two type of fibers that transmit the nerve action potentials
generated by excitation of any of the nociceptors - ANSWER-
Nociceptors = free nerve endings in the peripheral nervous system that
responds to chemical, mechanical, and thermal stimuli; when stimulated
they cause nociceptive pain. Two fibers are A-delta & C fibers ***see
question 7!
A-delta fibers: lightly myelinated, medium sized = faster transmission
C Fibers: unmyelinated, smaller sized = slower transmission
What is the relationship between epinephrine and body temperature? -
ANSWER- The hypothalamus releases TRH, which stimulates the
release of TSH, which acts on the thyroid gland and releases thyroxine.
Thyroxine then acts on the adrenal medulla, causing the release of
epinephrine into the bloodstream. Epinephrine causes cutaneous
, 4|P a g e
vasoconstriction, stimulates glycolysis, and increases metabolic rate,
increasing body heat (p484)
Epinephrine = body heat via chemical (nonshivering) thermogenesis
causes vasoconstriction, stimulates glycolysis, and increases metabolic
rate
Know mechanisms of heat production and heat loss - ANSWER- Heat
production: (1) chemical reactions of metabolism, (2) skeletal muscle
tone and contraction, (3) non-shivering thermogenesis. Heat loss: (1)
radiation, (2) conduction, (3) convection, (4) vasodilation, (5)
evaporation (sweating), (6) decreased muscle tone, (7) increased
respiration, (8) voluntary measures, (9) adaptation to warmer climate
(p484)
In human, body temperature is maintained around 37C (98.6F) and
rarely exceeds 41C. The normal range is 36.2C to 37.7C.Temperature
regulation (thermoregulation) is mediated by the hypothalamus;
peripheral thermoreceptors in the skin and abdominal organs
(unmyelinated C fibers and thinly myelinated A-delta fibers) and central
thermoreceptors in the spinal cord and trigeminal ganglia provide the
hypothalamus with information about skin and core temperatures
Know heat exhaustion and heat stroke - ANSWER- Heat exhaustion
results from prolonged high core or environmental temperatures that
caused vasodilation and profuse sweating, leading to dehydration,
decreased plasma volume, hypotension, decreased cardiac output, and
tachycardia. Symptoms include weakness, dizziness, confusion, nausea,
and fainting. Treatment includes oral or parenteral dilute salt solution.
NU 545 UNIT 2 ACTUAL 2026 EXAM |100
QUESTIONS AND CORRECT DETAILED
ANSWERS | RATED A+ | NEW AND
REVISED
Where in the CNS does pain perception occur? - ANSWER- Pain
perception occurs primarily in the reticular and limbic systems and the
cerebral cortex (p476)
It is the conscious awareness of pain; requires the interaction of three
systems:
1. Sensory-discriminative system
Mediated by: the somatosensory cortex
Responsibility: identifying the presence, character, location and intensity
of pain
2. Affective-motivational system
Mediated by: reticular formation, limbic system, and brainstem with
projections to the prefrontal cortex
Responsibility: individual conditioned avoidance behaviors and
emotional responses to pain
3. Cognitive-evaluative system
Mediated by: cerebral cortex
Responsibility: overlies individual's learned behavior concerning the
experience of pain and can modulate perception of pain
,2|P a g e
Know different clinical descriptions of pain (acute, chronic,
neuropathic); pain threshold/tolerance - ANSWER- 1. Neurophysiologic
Pain
2. Neurogenic Pain
3. Temporal Pain (time related, duration)
4. Pain Location
5. Etiologic Pain
(p480)
signal to the person of a harmful stimulus
· Normal & protective; lasts only seconds to days (up to 3 months)
· Begins suddenly and is relieved after stimulus is removed.
· Clinical signs are related to ANS: ↑HR, HTN, diaphoresis, dilated
pupils (476) (481)
Pain threshold & tolerance are subjective phenomena influence an
individual's perception of pain. Can be influenced by gender, culture,
expectations, role behaviors, physical/mental health, age, fatigue, anger,
boredom, apprehension, and sleep deprivation (Page 471)
Pain threshold: lowest intensity of pain a person can recognize. Different
areas of the body have different thresholds
Pain tolerance is the greatest intensity of pain that a person can endure
(p476)
Know endogenous opioids - ANSWER- A family of morphine-like
neuropeptides that inhibit transmission of pain impulses in the periphery,
spinal cord, and brain by binding with specific opioid receptors (mu,
,3|P a g e
kappa, delta). They inhibit ion channels, preventing the release of
excitatory neurotransmitters, such as substance P and glutamate, in the
dorsal horn (p478)
In the midbrain, they influence descending inhibitory pathways
· In peripheral inflamed tissue, opioids are produced and released from
leukocytes to activate opioid receptors on sensory nerve terminals. They
cannot cross the blood-brain barrier - this means they do not cause CNS
side effects like drowsiness, ↓respirations, or addiction
· Found in almost all tissues in the body. In addition to analgesia,
endogenous opioids are involved in a variety of other functions in the
body including modulating stress/anxiety, feeding behavior, cough
suppression, immune/inflammatory responses, and alcohol intak
Dynorphins for substance abuse and kappa receptors. (p479)
What are the two type of fibers that transmit the nerve action potentials
generated by excitation of any of the nociceptors - ANSWER-
Nociceptors = free nerve endings in the peripheral nervous system that
responds to chemical, mechanical, and thermal stimuli; when stimulated
they cause nociceptive pain. Two fibers are A-delta & C fibers ***see
question 7!
A-delta fibers: lightly myelinated, medium sized = faster transmission
C Fibers: unmyelinated, smaller sized = slower transmission
What is the relationship between epinephrine and body temperature? -
ANSWER- The hypothalamus releases TRH, which stimulates the
release of TSH, which acts on the thyroid gland and releases thyroxine.
Thyroxine then acts on the adrenal medulla, causing the release of
epinephrine into the bloodstream. Epinephrine causes cutaneous
, 4|P a g e
vasoconstriction, stimulates glycolysis, and increases metabolic rate,
increasing body heat (p484)
Epinephrine = body heat via chemical (nonshivering) thermogenesis
causes vasoconstriction, stimulates glycolysis, and increases metabolic
rate
Know mechanisms of heat production and heat loss - ANSWER- Heat
production: (1) chemical reactions of metabolism, (2) skeletal muscle
tone and contraction, (3) non-shivering thermogenesis. Heat loss: (1)
radiation, (2) conduction, (3) convection, (4) vasodilation, (5)
evaporation (sweating), (6) decreased muscle tone, (7) increased
respiration, (8) voluntary measures, (9) adaptation to warmer climate
(p484)
In human, body temperature is maintained around 37C (98.6F) and
rarely exceeds 41C. The normal range is 36.2C to 37.7C.Temperature
regulation (thermoregulation) is mediated by the hypothalamus;
peripheral thermoreceptors in the skin and abdominal organs
(unmyelinated C fibers and thinly myelinated A-delta fibers) and central
thermoreceptors in the spinal cord and trigeminal ganglia provide the
hypothalamus with information about skin and core temperatures
Know heat exhaustion and heat stroke - ANSWER- Heat exhaustion
results from prolonged high core or environmental temperatures that
caused vasodilation and profuse sweating, leading to dehydration,
decreased plasma volume, hypotension, decreased cardiac output, and
tachycardia. Symptoms include weakness, dizziness, confusion, nausea,
and fainting. Treatment includes oral or parenteral dilute salt solution.
