N6421 Neurological System: Central Nervous System assessment of brain and
spinal cord function, including motor system evaluation with upper and lower
motor neuron testing, corticospinal and extrapyramidal (basal ganglia) tracts,
cerebellar coordination, muscle size, tone, strength (Oxford 0–5 scale),
involuntary movements, rapid alternating movements, and balance via gait,
Romberg, heel-to-shin, and tandem walking; sensory system testing of
spinothalamic and posterior column tracts for pain, temperature, light touch,
vibration, proprioception, stereognosis, graphesthesia, two-point
discrimination, point localization, and extinction; cranial nerves I–XII assessment
for olfaction, vision, extraocular movement, pupillary reflexes, facial movement
and sensation, hearing, taste, swallowing, gag, shoulder shrug, head rotation,
and tongue movement; deep tendon reflexes (biceps C5–C6, triceps C7–C8,
brachioradialis C5–C6, quadriceps L2–L4, Achilles L5–S2) Exam Questions
Verified and Provided with Complete A+ Graded Rationales Latest Updated 2026
Central nervous system
Brain
Spinal cord
Peripheral nervous system
Somatic
Autonomic
Sympathetic
Parasympathetic
Damage to cerebral cortex
Damage can occur when neurological cells are damaged or deprived of blood supply (trauma or CVA)
,Damage to specific cortical areas produces corresponding loss of function: motor weakness, paralysis,
loss of sensation, impaired ability to understand and process language
The spinal cord
Extends from brainstem (medulla) to L1-L2 vertebrae
Contains motor and sensory pathways that exit and enter the cord via anterior and posterior nerve roots
and spinal and peripheral nerves
5 segments: cervical (C1-8), thoracic (T1-12), lumbar (L1-5), sacral (S1-5), coccygeal
Peripheral nervous system
12 pairs of cranial nerves plus spinal and peripheral nerves
Cranial nerves govern motor, sensory, and specialized functions like smell, vision, and hearing
Peripheral nerves
31 pairs of nerves that attach to the spinal cord: 8 cervical, 2 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
Each nerve has an anterior (ventral) root containing motor fibers and a posterior (dorsal) root containing
sensory fibers; the anterior and posterior roots merge to form a short (<5 mm) spinal nerve
Spinal nerve fibers join with similar fibers from other levels to form peripheral nerves
Sensory pathways
Millions of sensory receptors are found in skin, mucous membranes, muscles, tendons, and viscera
Monitor conscious sensation, internal organ functions, body position, and reflexes
Sensation travels in afferent fibers in peripheral nerve, through posterior (dorsal) root, and into spinal
cord
There, may take one of two routes: spinothalamic tract or posterior (dorsal) columns
, Spinothalamic tract
Contains sensory fibers that transmit sensations of pain, temperature, and crude or light touch
Fibers enter dorsal root of spinal cord and synapse with a second sensory neuron
At thalamus, fibers synapse with third sensory neuron, carrying message to sensory cortex for full
interpretation
Posterior (dorsal) columns
These fibers conduct sensations of proprioception, kinesthesis, pressure and find touch (stereognosis)
Sensory pathways
Sensory cortex arranged in corresponding "map" of body; pain in right hand perceived at specific spot
on left cortex map
Some organs absent from brain map, such as heart, liver, or spleen
Pain originating in these organs is referred, e.g., heart pain is referred to chest, shoulder, and left arm,
pain originating in spleen felt on left shoulder
Complex pathways
extend from upper motor neurons through long white matter and synapses with lower motor neurons
and continue through the periphery through peripheral nerve structures
upper motor neurons
lie in the motor strip of the cerebral cortex and in several brainstem nuclei - axons synapse with motor
nuclei in the brain stem (for cranial nerves) and in the spinal cord (for peripheral nerves)
spinal cord function, including motor system evaluation with upper and lower
motor neuron testing, corticospinal and extrapyramidal (basal ganglia) tracts,
cerebellar coordination, muscle size, tone, strength (Oxford 0–5 scale),
involuntary movements, rapid alternating movements, and balance via gait,
Romberg, heel-to-shin, and tandem walking; sensory system testing of
spinothalamic and posterior column tracts for pain, temperature, light touch,
vibration, proprioception, stereognosis, graphesthesia, two-point
discrimination, point localization, and extinction; cranial nerves I–XII assessment
for olfaction, vision, extraocular movement, pupillary reflexes, facial movement
and sensation, hearing, taste, swallowing, gag, shoulder shrug, head rotation,
and tongue movement; deep tendon reflexes (biceps C5–C6, triceps C7–C8,
brachioradialis C5–C6, quadriceps L2–L4, Achilles L5–S2) Exam Questions
Verified and Provided with Complete A+ Graded Rationales Latest Updated 2026
Central nervous system
Brain
Spinal cord
Peripheral nervous system
Somatic
Autonomic
Sympathetic
Parasympathetic
Damage to cerebral cortex
Damage can occur when neurological cells are damaged or deprived of blood supply (trauma or CVA)
,Damage to specific cortical areas produces corresponding loss of function: motor weakness, paralysis,
loss of sensation, impaired ability to understand and process language
The spinal cord
Extends from brainstem (medulla) to L1-L2 vertebrae
Contains motor and sensory pathways that exit and enter the cord via anterior and posterior nerve roots
and spinal and peripheral nerves
5 segments: cervical (C1-8), thoracic (T1-12), lumbar (L1-5), sacral (S1-5), coccygeal
Peripheral nervous system
12 pairs of cranial nerves plus spinal and peripheral nerves
Cranial nerves govern motor, sensory, and specialized functions like smell, vision, and hearing
Peripheral nerves
31 pairs of nerves that attach to the spinal cord: 8 cervical, 2 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
Each nerve has an anterior (ventral) root containing motor fibers and a posterior (dorsal) root containing
sensory fibers; the anterior and posterior roots merge to form a short (<5 mm) spinal nerve
Spinal nerve fibers join with similar fibers from other levels to form peripheral nerves
Sensory pathways
Millions of sensory receptors are found in skin, mucous membranes, muscles, tendons, and viscera
Monitor conscious sensation, internal organ functions, body position, and reflexes
Sensation travels in afferent fibers in peripheral nerve, through posterior (dorsal) root, and into spinal
cord
There, may take one of two routes: spinothalamic tract or posterior (dorsal) columns
, Spinothalamic tract
Contains sensory fibers that transmit sensations of pain, temperature, and crude or light touch
Fibers enter dorsal root of spinal cord and synapse with a second sensory neuron
At thalamus, fibers synapse with third sensory neuron, carrying message to sensory cortex for full
interpretation
Posterior (dorsal) columns
These fibers conduct sensations of proprioception, kinesthesis, pressure and find touch (stereognosis)
Sensory pathways
Sensory cortex arranged in corresponding "map" of body; pain in right hand perceived at specific spot
on left cortex map
Some organs absent from brain map, such as heart, liver, or spleen
Pain originating in these organs is referred, e.g., heart pain is referred to chest, shoulder, and left arm,
pain originating in spleen felt on left shoulder
Complex pathways
extend from upper motor neurons through long white matter and synapses with lower motor neurons
and continue through the periphery through peripheral nerve structures
upper motor neurons
lie in the motor strip of the cerebral cortex and in several brainstem nuclei - axons synapse with motor
nuclei in the brain stem (for cranial nerves) and in the spinal cord (for peripheral nerves)
