NCS Neuroanatomy and Physiology 3

Question 1

In the spinal cord, the spinothalamic tract carries pain and temperature information and crosses at which level?

Accepted Answer

Within 1-2 spinal segments of entry via the anterior commissure

Answer

Second-order spinothalamic neurons cross the midline through the anterior white commissure within 1-2 segments of their dorsal horn synapse before ascending contralaterally.

Question 2

The preganglionic sympathetic neurons are located in which spinal cord region?

Accepted Answer

T1-L2 intermediolateral cell column

Answer

Sympathetic preganglionic neurons are located in the intermediolateral cell column (lateral horn) of spinal cord segments T1 through L2.

Question 3

Which ascending tract conveys proprioception from the lower limb directly to the ipsilateral cerebellum without relay in the thalamus?

Accepted Answer

Posterior spinocerebellar tract

Answer

The posterior spinocerebellar tract transmits unconscious proprioception from the lower limb ipsilaterally through the inferior cerebellar peduncle directly to the cerebellar cortex.

Question 4

Which spinal cord segment level corresponds to the umbilicus dermatome, a key landmark for sensory level testing?

Accepted Answer

T10

Answer

The umbilicus is innervated by the T10 dermatome, making it a standard clinical landmark for determining the level of a thoracic spinal cord lesion.

Question 5

In the autonomic nervous system, postganglionic parasympathetic fibers release which neurotransmitter to act on target organs?

Accepted Answer

Acetylcholine acting on muscarinic receptors

Answer

Postganglionic parasympathetic fibers release acetylcholine that acts on muscarinic receptors of target organs, while nicotinic receptors are found at all autonomic ganglia.

(NCS) Neurologic Clinical Specialist Practice Test

(NCS) Neurologic Clinical Specialist Practice Test

NCS Neuroanatomy and Physiology 3