BIOL251 MODULE 7: THE NERVOUS
SYSTEM AND SPECIAL SENSES| 50
QUESTIONS | PORTAGE LEARNING
1. Which of the following neuroglial cells is responsible for forming the blood-brain barrier in
the central nervous system?
A. Microglia
B. Ependymal cells
C. Oligodendrocytes
D. Astrocytes
Answer: D
Conceptual Explanation: Astrocytes have perivascular feet that wrap around capillaries,
creating a physical barrier and regulating the passage of substances into the brain tissue.
2. Damage to the Wernicke’s area, typically located in the left temporal lobe, would most
likely result in which clinical condition?
A. Inability to produce speech (motor aphasia)
B. Inability to understand spoken or written language (receptive aphasia)
,C. Loss of equilibrium and balance
D. Permanent loss of long-term memory
Answer: B
Conceptual Explanation: Wernicke’s area is crucial for language comprehension. Damage
leads to receptive aphasia, where speech remains fluent but lacks meaning.
3. Which cranial nerve is primarily responsible for the motor innervation of the muscles of
mastication?
A. CN V (Trigeminal)
B. CN VII (Facial)
C. CN IX (Glossopharyngeal)
D. CN XII (Hypoglossal)
Answer: A
Conceptual Explanation: The mandibular branch (V3) of the Trigeminal nerve provides
motor control for muscles involved in chewing, such as the masseter and temporalis.
4. During an action potential, the rapid depolarization phase is caused by the:
A. Efflux of potassium ions
B. Closing of calcium channels
C. Influx of sodium ions
, D. Active transport of chloride ions
Answer: C
Conceptual Explanation: Depolarization occurs when voltage-gated sodium channels
open, allowing Na+ to rush into the cell, making the membrane potential more positive.
5. In the autonomic nervous system, which neurotransmitter is released by all preganglionic
neurons?
A. Acetylcholine
B. Epinephrine
C. Dopamine
D. Norepinephrine
Answer: A
Conceptual Explanation: Both sympathetic and parasympathetic preganglionic neurons
release Acetylcholine (ACh), which binds to nicotinic receptors on the postganglionic
neuron.
6. Which part of the brain acts as the primary relay station for all sensory information, except
olfaction, heading to the cerebral cortex?
A. Hypothalamus
B. Pons
C. Cerebellum
SYSTEM AND SPECIAL SENSES| 50
QUESTIONS | PORTAGE LEARNING
1. Which of the following neuroglial cells is responsible for forming the blood-brain barrier in
the central nervous system?
A. Microglia
B. Ependymal cells
C. Oligodendrocytes
D. Astrocytes
Answer: D
Conceptual Explanation: Astrocytes have perivascular feet that wrap around capillaries,
creating a physical barrier and regulating the passage of substances into the brain tissue.
2. Damage to the Wernicke’s area, typically located in the left temporal lobe, would most
likely result in which clinical condition?
A. Inability to produce speech (motor aphasia)
B. Inability to understand spoken or written language (receptive aphasia)
,C. Loss of equilibrium and balance
D. Permanent loss of long-term memory
Answer: B
Conceptual Explanation: Wernicke’s area is crucial for language comprehension. Damage
leads to receptive aphasia, where speech remains fluent but lacks meaning.
3. Which cranial nerve is primarily responsible for the motor innervation of the muscles of
mastication?
A. CN V (Trigeminal)
B. CN VII (Facial)
C. CN IX (Glossopharyngeal)
D. CN XII (Hypoglossal)
Answer: A
Conceptual Explanation: The mandibular branch (V3) of the Trigeminal nerve provides
motor control for muscles involved in chewing, such as the masseter and temporalis.
4. During an action potential, the rapid depolarization phase is caused by the:
A. Efflux of potassium ions
B. Closing of calcium channels
C. Influx of sodium ions
, D. Active transport of chloride ions
Answer: C
Conceptual Explanation: Depolarization occurs when voltage-gated sodium channels
open, allowing Na+ to rush into the cell, making the membrane potential more positive.
5. In the autonomic nervous system, which neurotransmitter is released by all preganglionic
neurons?
A. Acetylcholine
B. Epinephrine
C. Dopamine
D. Norepinephrine
Answer: A
Conceptual Explanation: Both sympathetic and parasympathetic preganglionic neurons
release Acetylcholine (ACh), which binds to nicotinic receptors on the postganglionic
neuron.
6. Which part of the brain acts as the primary relay station for all sensory information, except
olfaction, heading to the cerebral cortex?
A. Hypothalamus
B. Pons
C. Cerebellum
