BIOL251 MODULE 3 EXAM REVIEW:
NERVOUS SYSTEM AND SPECIAL
SENSES| 50 QUESTIONS | PORTAGE
LEARNING
1. Which neuroglial cell type is responsible for forming the myelin sheath around axons
within the Central Nervous System (CNS)?
A. Schwann cells
B. Oligodendrocytes
C. Astrocytes
D. Microglia
Answer: B
Conceptual Explanation: Oligodendrocytes myelinate multiple axon segments in the CNS,
whereas Schwann cells perform this function in the Peripheral Nervous System (PNS).
2. During the depolarization phase of an action potential, which of the following events
occurs?
A. Voltage-gated potassium channels open rapidly
,B. Voltage-gated sodium channels open, allowing sodium to enter the cell
C. Sodium ions exit the cell
D. The membrane potential becomes more negative
Answer: B
Conceptual Explanation: Depolarization is characterized by the rapid influx of sodium
ions (Na+) through voltage-gated channels, shifting the membrane potential towards a
positive value.
3. Which part of the brain is primarily responsible for the coordination of complex motor
patterns and maintaining equilibrium?
A. Cerebellum
B. Cerebrum
C. Thalamus
D. Medulla Oblongata
Answer: A
Conceptual Explanation: The cerebellum processes input from the motor cortex and
sensory receptors to provide precise timing and appropriate patterns of skeletal muscle
contraction.
4. The ‘fight or flight’ response is mediated by which division of the nervous system?
A. Parasympathetic Division
, B. Somatic Nervous System
C. Sympathetic Division
D. Enteric Nervous System
Answer: C
Conceptual Explanation: The sympathetic division of the autonomic nervous system
prepares the body for stressful or emergency situations.
5. Which cranial nerve is unique because it travels inferiorly into the thorax and abdomen to
provide parasympathetic innervation to visceral organs?
A. Cranial Nerve X (Vagus)
B. Cranial Nerve IX (Glossopharyngeal)
C. Cranial Nerve XII (Hypoglossal)
D. Cranial Nerve V (Trigeminal)
Answer: A
Conceptual Explanation: The Vagus nerve is the only cranial nerve that extends beyond
the head and neck region to innervate the thoracic and abdominal viscera.
6. The gaps in the myelin sheath along a myelinated axon, where voltage-gated ion channels
are concentrated, are called:
A. Nodes of Ranvier
B. Synaptic clefts
NERVOUS SYSTEM AND SPECIAL
SENSES| 50 QUESTIONS | PORTAGE
LEARNING
1. Which neuroglial cell type is responsible for forming the myelin sheath around axons
within the Central Nervous System (CNS)?
A. Schwann cells
B. Oligodendrocytes
C. Astrocytes
D. Microglia
Answer: B
Conceptual Explanation: Oligodendrocytes myelinate multiple axon segments in the CNS,
whereas Schwann cells perform this function in the Peripheral Nervous System (PNS).
2. During the depolarization phase of an action potential, which of the following events
occurs?
A. Voltage-gated potassium channels open rapidly
,B. Voltage-gated sodium channels open, allowing sodium to enter the cell
C. Sodium ions exit the cell
D. The membrane potential becomes more negative
Answer: B
Conceptual Explanation: Depolarization is characterized by the rapid influx of sodium
ions (Na+) through voltage-gated channels, shifting the membrane potential towards a
positive value.
3. Which part of the brain is primarily responsible for the coordination of complex motor
patterns and maintaining equilibrium?
A. Cerebellum
B. Cerebrum
C. Thalamus
D. Medulla Oblongata
Answer: A
Conceptual Explanation: The cerebellum processes input from the motor cortex and
sensory receptors to provide precise timing and appropriate patterns of skeletal muscle
contraction.
4. The ‘fight or flight’ response is mediated by which division of the nervous system?
A. Parasympathetic Division
, B. Somatic Nervous System
C. Sympathetic Division
D. Enteric Nervous System
Answer: C
Conceptual Explanation: The sympathetic division of the autonomic nervous system
prepares the body for stressful or emergency situations.
5. Which cranial nerve is unique because it travels inferiorly into the thorax and abdomen to
provide parasympathetic innervation to visceral organs?
A. Cranial Nerve X (Vagus)
B. Cranial Nerve IX (Glossopharyngeal)
C. Cranial Nerve XII (Hypoglossal)
D. Cranial Nerve V (Trigeminal)
Answer: A
Conceptual Explanation: The Vagus nerve is the only cranial nerve that extends beyond
the head and neck region to innervate the thoracic and abdominal viscera.
6. The gaps in the myelin sheath along a myelinated axon, where voltage-gated ion channels
are concentrated, are called:
A. Nodes of Ranvier
B. Synaptic clefts
