BIOL 251: Human Anatomy & Physiology I w/Lab 2026 - 2027
Portage learning
Module 7: Peripheral Nervous System, Reflex Activity, and the PNS
Complete Exam Review Questions with Verified Answers |
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Question 1
Which sensory receptor is responsible for detecting the position and
movement of the body?
A) Nociceptors
B) Exteroceptors
C) Interoceptors
D) Proprioceptors
Correct Answer: D) Proprioceptors
Explanation: Proprioceptors detect the position and movement of the
body (proprioception). They are located in muscles, tendons, and
joints and provide information about body position, muscle tension,
and joint angle. Nociceptors detect pain. Exteroceptors detect
external stimuli (touch, pressure, temperature). Interoceptors
detect internal stimuli (visceral sensations). Proprioceptors are
essential for balance, coordination, and fine motor control.
,Question 2
True or False: Ruffini's corpuscles detect stretch, sustained pressure, and
warmth.
A) True
B) False
Correct Answer: A) True
Explanation: Ruffini's corpuscles (Ruffini endings) detect stretch,
sustained pressure, and warmth. They are slowly adapting
mechanoreceptors found in the dermis and joint capsules. They
provide information about skin stretching, joint position, and
continuous pressure. Meissner's corpuscles detect light touch.
Pacinian corpuscles detect deep pressure and vibration. Ruffini's
corpuscles are important for proprioception and tactile
discrimination.
Question 3
What is paradoxical cold?
A) When warm receptors mistakenly signal cold sensations
B) When cold receptors stop firing in extremely cold conditions
C) When cold receptors fire in response to an extreme heat stimulus
D) When both warm and cold receptors stop firing simultaneously
,Correct Answer: C) When cold receptors fire in response to an
extreme heat stimulus
Explanation: Paradoxical cold occurs when cold receptors fire in
response to an extreme heat stimulus (typically above 45°C),
causing a sensation of cold despite the stimulus being hot. This
phenomenon is due to the activation of cold receptors by noxious
heat. Warm receptors mistakenly signaling cold is not the correct
mechanism. This illustrates how sensory perception can be complex
and counterintuitive.
Question 4
Which structure in the spinal cord receives incoming sensory
information?
A) Central canal
B) Ventral horn
C) Anterior horn
D) Dorsal horn
Correct Answer: D) Dorsal horn
Explanation: The dorsal horn of the spinal cord receives incoming
sensory information from sensory neurons. Sensory fibers enter
the spinal cord through the dorsal root and synapse in the dorsal
horn. The ventral horn (anterior horn) contains motor neuron cell
bodies that send motor signals out through the ventral root. The
, central canal contains cerebrospinal fluid. The dorsal horn is the
processing center for sensory information in the spinal cord.
Question 5
Which of the following statements is true about polysynaptic reflex arcs?
A) They are faster than monosynaptic reflex arcs.
B) They involve only two neurons.
C) They allow only a single muscle group to respond.
D) They involve an interneuron for more complex processing.
Correct Answer: D) They involve an interneuron for more complex
processing.
Explanation: Polysynaptic reflex arcs involve an interneuron
between the sensory and motor neurons, allowing for more complex
processing. They are slower than monosynaptic reflex arcs (which
have only two neurons). Polysynaptic reflexes can involve multiple
muscle groups and are more complex, allowing for coordinated
responses such as withdrawal reflexes. Monosynaptic reflexes (e.g.,
knee-jerk reflex) are faster and involve only two neurons.
Question 6
Which of the following is an example of an effector in a reflex arc?
Portage learning
Module 7: Peripheral Nervous System, Reflex Activity, and the PNS
Complete Exam Review Questions with Verified Answers |
LockDown Browser (GUARANTEED PASS)
Question 1
Which sensory receptor is responsible for detecting the position and
movement of the body?
A) Nociceptors
B) Exteroceptors
C) Interoceptors
D) Proprioceptors
Correct Answer: D) Proprioceptors
Explanation: Proprioceptors detect the position and movement of the
body (proprioception). They are located in muscles, tendons, and
joints and provide information about body position, muscle tension,
and joint angle. Nociceptors detect pain. Exteroceptors detect
external stimuli (touch, pressure, temperature). Interoceptors
detect internal stimuli (visceral sensations). Proprioceptors are
essential for balance, coordination, and fine motor control.
,Question 2
True or False: Ruffini's corpuscles detect stretch, sustained pressure, and
warmth.
A) True
B) False
Correct Answer: A) True
Explanation: Ruffini's corpuscles (Ruffini endings) detect stretch,
sustained pressure, and warmth. They are slowly adapting
mechanoreceptors found in the dermis and joint capsules. They
provide information about skin stretching, joint position, and
continuous pressure. Meissner's corpuscles detect light touch.
Pacinian corpuscles detect deep pressure and vibration. Ruffini's
corpuscles are important for proprioception and tactile
discrimination.
Question 3
What is paradoxical cold?
A) When warm receptors mistakenly signal cold sensations
B) When cold receptors stop firing in extremely cold conditions
C) When cold receptors fire in response to an extreme heat stimulus
D) When both warm and cold receptors stop firing simultaneously
,Correct Answer: C) When cold receptors fire in response to an
extreme heat stimulus
Explanation: Paradoxical cold occurs when cold receptors fire in
response to an extreme heat stimulus (typically above 45°C),
causing a sensation of cold despite the stimulus being hot. This
phenomenon is due to the activation of cold receptors by noxious
heat. Warm receptors mistakenly signaling cold is not the correct
mechanism. This illustrates how sensory perception can be complex
and counterintuitive.
Question 4
Which structure in the spinal cord receives incoming sensory
information?
A) Central canal
B) Ventral horn
C) Anterior horn
D) Dorsal horn
Correct Answer: D) Dorsal horn
Explanation: The dorsal horn of the spinal cord receives incoming
sensory information from sensory neurons. Sensory fibers enter
the spinal cord through the dorsal root and synapse in the dorsal
horn. The ventral horn (anterior horn) contains motor neuron cell
bodies that send motor signals out through the ventral root. The
, central canal contains cerebrospinal fluid. The dorsal horn is the
processing center for sensory information in the spinal cord.
Question 5
Which of the following statements is true about polysynaptic reflex arcs?
A) They are faster than monosynaptic reflex arcs.
B) They involve only two neurons.
C) They allow only a single muscle group to respond.
D) They involve an interneuron for more complex processing.
Correct Answer: D) They involve an interneuron for more complex
processing.
Explanation: Polysynaptic reflex arcs involve an interneuron
between the sensory and motor neurons, allowing for more complex
processing. They are slower than monosynaptic reflex arcs (which
have only two neurons). Polysynaptic reflexes can involve multiple
muscle groups and are more complex, allowing for coordinated
responses such as withdrawal reflexes. Monosynaptic reflexes (e.g.,
knee-jerk reflex) are faster and involve only two neurons.
Question 6
Which of the following is an example of an effector in a reflex arc?
