MCV4U UNIT 4 ASSESSMENT PAPER 2026
FULL SOLUTION QUESTIONS VERIFIED
RESULTS GRADED A+
●● Differentiate between central and peripheral nervous systems based
on structure and function.
Answer: The CNS (brain and spinal cord) processes information, while
the PNS carries sensory and motor signals to and from the CNS.
●● Explain the difference between afferent and efferent pathways.
Answer: Afferent pathways carry sensory input to the brain, while
efferent pathways carry motor output from the brain.
●● Describe the concept of contralateral control in the brain.
Answer: Each side of the brain controls the opposite side of the body.
●● Explain how upper motor neuron lesions lead to spasticity.
Answer: Loss of inhibitory control from the brain causes increased
reflexes and muscle tone, leading to spasticity.
●● Explain how lower motor neuron lesions lead to flaccidity and
muscle atrophy.
, Answer: Damage prevents signals from reaching muscles, causing
decreased tone, loss of reflexes, and muscle wasting.
●● Describe how the level of spinal cord injury determines functional
loss.
Answer: Higher injuries cause more widespread paralysis, while lower
injuries affect fewer body regions.
●● Explain how increased intracranial pressure affects brain function.
Answer: It compresses brain tissue, reduces blood flow, and impairs
oxygen delivery, leading to dysfunction.
●● Describe how brain herniation occurs due to increased pressure.
Answer: Increased pressure forces brain tissue into abnormal spaces,
compressing vital structures.
●● Explain how accumulation of cerebrospinal fluid leads to
hydrocephalus.
Answer: CSF buildup increases pressure in the ventricles, enlarging the
head and compressing brain tissue.
●● Compare meningitis and encephalitis based on structures affected.
Answer: Meningitis affects the meninges, while encephalitis affects
brain tissue.
FULL SOLUTION QUESTIONS VERIFIED
RESULTS GRADED A+
●● Differentiate between central and peripheral nervous systems based
on structure and function.
Answer: The CNS (brain and spinal cord) processes information, while
the PNS carries sensory and motor signals to and from the CNS.
●● Explain the difference between afferent and efferent pathways.
Answer: Afferent pathways carry sensory input to the brain, while
efferent pathways carry motor output from the brain.
●● Describe the concept of contralateral control in the brain.
Answer: Each side of the brain controls the opposite side of the body.
●● Explain how upper motor neuron lesions lead to spasticity.
Answer: Loss of inhibitory control from the brain causes increased
reflexes and muscle tone, leading to spasticity.
●● Explain how lower motor neuron lesions lead to flaccidity and
muscle atrophy.
, Answer: Damage prevents signals from reaching muscles, causing
decreased tone, loss of reflexes, and muscle wasting.
●● Describe how the level of spinal cord injury determines functional
loss.
Answer: Higher injuries cause more widespread paralysis, while lower
injuries affect fewer body regions.
●● Explain how increased intracranial pressure affects brain function.
Answer: It compresses brain tissue, reduces blood flow, and impairs
oxygen delivery, leading to dysfunction.
●● Describe how brain herniation occurs due to increased pressure.
Answer: Increased pressure forces brain tissue into abnormal spaces,
compressing vital structures.
●● Explain how accumulation of cerebrospinal fluid leads to
hydrocephalus.
Answer: CSF buildup increases pressure in the ventricles, enlarging the
head and compressing brain tissue.
●● Compare meningitis and encephalitis based on structures affected.
Answer: Meningitis affects the meninges, while encephalitis affects
brain tissue.
