Physiology I w/ Lab | Portage Learning | Q & A | 2026/2027
(PDF)
**1. What are the two major divisions of the peripheral nervous system (PNS)?**
A) Central and peripheral
B) Sensory (afferent) and motor (efferent)
C) Sympathetic and parasympathetic
D) Somatic and autonomic
Correct Answer: Sensory (afferent) and motor (efferent)
Rationale: The PNS is structurally divided into the sensory (afferent) division, which carries signals
toward the CNS, and the motor (efferent) division, which carries signals away from the CNS to effectors.
The somatic and autonomic systems are subdivisions of the motor division, while sympathetic and
parasympathetic are divisions of the autonomic nervous system.
**2. Which division of the PNS is further subdivided into the somatic nervous system and the autonomic
nervous system?**
A) Sensory (afferent) division
B) Motor (efferent) division
C) Central nervous system
D) Enteric nervous system
Correct Answer: Motor (efferent) division
Rationale: The motor (efferent) division of the PNS is subdivided into the somatic nervous system, which
controls voluntary skeletal muscle movement, and the autonomic nervous system (ANS), which
regulates involuntary functions such as heart rate, digestion, and glandular secretion.
**3. What type of neurons are found in the sensory (afferent) division of the PNS?**
,A) Multipolar neurons
B) Bipolar neurons
C) Unipolar (pseudounipolar) neurons
D) Anaxonic neurons
Correct Answer: Unipolar (pseudounipolar) neurons
Rationale: Sensory neurons in the PNS are unipolar (pseudounipolar). Their cell bodies are located in the
dorsal root ganglia (spinal nerves) or cranial nerve ganglia. Their axons have a single process that splits
into a peripheral branch (to receptors) and a central branch (to the CNS).
**4. Which of the following best defines a nerve?**
A) A single neuron
B) A bundle of axons in the CNS
C) A bundle of axons in the PNS wrapped in connective tissue
D) A collection of cell bodies in the CNS
Correct Answer: A bundle of axons in the PNS wrapped in connective tissue
Rationale: A nerve is a bundle of axons (nerve fibers) located in the PNS, wrapped in connective tissue
layers (endoneurium, perineurium, epineurium). Nerves may be sensory, motor, or mixed (containing
both sensory and motor fibers).
**5. Which type of receptor responds specifically to pain-causing stimuli?**
A) Mechanoreceptor
B) Thermoreceptor
C) Nociceptor
D) Photoreceptor
Correct Answer: Nociceptor
, Rationale: Nociceptors are specialized free nerve endings that signal actual or potential tissue damage in
response to pain-causing stimuli like extreme heat or inflammatory chemicals. Mechanoreceptors
respond to touch/pressure, thermoreceptors to temperature, and photoreceptors to light.
**6. "Proprioceptors" provide information about which of the following?**
A) Light intensity
B) Body position and movement
C) Blood pressure
D) Odors
Correct Answer: Body position and movement
Rationale: Proprioceptors monitor the stretch in skeletal muscles, tendons, and joint capsules to inform
the brain of our body's location in space. They are essential for maintaining balance and coordinating
movement.
**7. Which nerve of the brachial plexus is often compressed in "Carpal Tunnel Syndrome"?**
A) Radial nerve
B) Ulnar nerve
C) Median nerve
D) Axillary nerve
Correct Answer: Median nerve
Rationale: The median nerve, which passes through the carpal tunnel of the wrist, is often compressed
in Carpal Tunnel Syndrome. This compression leads to pain, numbness, and tingling in the hand.
**8. A patient reports a loss of smell and is unable to identify familiar odors. This symptom is most likely
due to damage to which cranial nerve?**
A) Optic nerve (II)