EDT Neuroanatomy & Physiology 2

Question 1

Which ion channel is primarily responsible for the rising phase of an action potential?

Accepted Answer

Voltage-gated sodium channels

Answer

Voltage-gated sodium channels open rapidly in response to membrane depolarization, allowing Na⁺ influx that drives the rising phase of the action potential.

Question 2

The dorsal root ganglion (DRG) contains the cell bodies of which neuron type?

Accepted Answer

Primary sensory afferent neurons

Answer

The DRG houses the cell bodies of primary sensory (afferent) neurons that transmit sensory signals from the periphery to the spinal cord.

Question 3

What is the approximate conduction velocity range for Aβ sensory fibers?

Accepted Answer

30–70 m/s

Answer

Aβ fibers are myelinated and conduct at 30–70 m/s, carrying touch and pressure information.

Question 4

Which spinal cord tract carries proprioceptive information ipsilaterally to the cerebellum?

Accepted Answer

Dorsal spinocerebellar tract

Answer

The dorsal spinocerebellar tract conveys unconscious proprioceptive signals from the lower limb ipsilaterally to the cerebellum.

Question 5

Saltatory conduction in myelinated nerves occurs because action potentials jump between which structures?

Accepted Answer

Nodes of Ranvier

Answer

In myelinated fibers, depolarization skips from one node of Ranvier to the next, dramatically increasing conduction velocity.

(EDT) Electrodiagnostic Technician Certification Practice Test

(EDT) Electrodiagnostic Technician Certification Practice Test

EDT Neuroanatomy & Physiology 2