Question

which of the following statements regarding the spinal cord is not true?
a ascending tracts carry sensory information up to the brain.
b cerebrospinal fluid is found within the central canal of the spinal cord.
c descending tracts carry motor commands from the brain to a peripheral nerve.
d the spinal cord extends from the medulla oblongata down to the sacrum.

Explanation:

• Option A: Ascending tracts indeed carry sensory information to the brain. This is a correct statement.
• Option B: Cerebrospinal fluid is present in the central canal of the spinal cord. This is a correct statement.
• Option C: Descending tracts carry motor commands from the brain to peripheral nerves. This is a correct statement.
• Option D: The spinal cord extends from the medulla oblongata down to the level of the first or second lumbar vertebra (not the sacrum). So this statement is not true.

Answer:

D. The spinal cord extends from the medulla oblongata down to the sacrum.