Health & Illness (2026) Q&A
1. The primary motor cortex (M1) is located in which lobe of the brain?
A) Frontal lobe
B) Parietal lobe
C) Temporal lobe
D) Occipital lobe
Correct Answer: Frontal lobe
Rationale: The primary motor cortex (M1) is located in the frontal lobe, specifically
in the precentral gyrus. It is the primary source of descending motor signals for
voluntary movement. The precentral gyrus lies immediately anterior to the central
sulcus.
2. The premotor cortex is involved in which function?
A) Execution of fine motor movements
B) Planning and organizing movements
C) Coordination of balance
D) Processing sensory information
Correct Answer: Planning and organizing movements
Rationale: The premotor cortex is involved in the planning and organization of
movements, especially complex sequences. It projects to M1 and the spinal cord. It
is located anterior to the primary motor cortex.
3. The supplementary motor area (SMA) is primarily involved in which function?
A) Fine motor control
B) Planning and initiating complex sequences of movements
,C) Sensory processing
D) Coordination of eye movements
Correct Answer: Planning and initiating complex sequences of movements
Rationale: The supplementary motor area is involved in the planning and initiation
of complex sequences of movements, particularly bimanual movements. It is
located in the medial aspect of the frontal lobe.
4. Which tract is the primary descending pathway for voluntary movement?
A) Spinothalamic tract
B) Corticospinal tract
C) Dorsal column - medial lemniscus pathway
D) Rubrospinal tract
Correct Answer: Corticospinal tract
Rationale: The corticospinal tract is the primary descending pathway for voluntary
movement. It originates in M1, premotor cortex, and SMA, and descends through the
internal capsule, brainstem, and spinal cord to synapse on lower motor neurons.
5. The corticospinal tract decussates (crosses) at which structure?
A) Pons
B) Medulla (pyramidal decussation)
C) Midbrain
D) Spinal cord
Correct Answer: Medulla (pyramidal decussation)
Rationale: The corticospinal tract decussates at the medullary pyramids
(pyramidal decussation). Approximately 85 - 90% of fibers cross to the contralateral
side. This explains why the left motor cortex controls the right side of the body.
, 6. Which basal ganglia nucleus is the major output nucleus?
A) Caudate
B) Putamen
C) Globus pallidus internal segment (GPi)
D) Subthalamic nucleus
Correct Answer: Globus pallidus internal segment (GPi)
Rationale: The globus pallidus internal segment (GPi) is the major output nucleus
of the basal ganglia, along with the substantia nigra pars reticulata (SNr). GPi and
SNr project to the thalamus, which then projects to the motor cortex.
7. All of the following are true about the monoamine hypothesis except?
A) It explains the delay in response seen with depression treatments
B) It posits that depression is due to a deficiency in monoamines
C) It is the primary hypothesis for the mechanism of antidepressant action
D) It accounts for the neuroplastic changes seen with chronic antidepressant use
Correct Answer: It explains the delay in response seen with depression
treatments
Rationale: The monoamine hypothesis does not explain the delay in response seen
with depression treatments. Antidepressants increase monoamine levels within
hours, but clinical improvement takes weeks, suggesting that downstream
neuroplastic changes are required.
8. Postmortem studies in depressed patients have found all of the following except?
A) Reduced neurons in the hypothalamus
B) Reduced glial cells in the prefrontal cortex
C) Reduced hippocampal volume
D) Increased glutamate levels in the occipital cortex