ATI RN
Autonomic Nervous System NCLEX Questions Questions
Question 1 of 5
Autoreceptors of the sympathetic division that are involved in negative feedback are the:
Correct Answer: B
Rationale: α₂ autoreceptors on presynaptic terminals inhibit norepinephrine release (negative feedback). Other receptors (α₁, β₁, β₂) mediate effector responses.
Question 2 of 5
The knee jerk in response to a tap over the patellar tendon:
Correct Answer: C
Rationale: The knee jerk is a monosynaptic spinal reflex with its center in the spinal cord (L2-L4), not conditioned or polysynaptic.
Question 3 of 5
The speed of a nerve impulse is independent of the:
Correct Answer: D
Rationale: Impulse speed depends on fiber diameter, myelination (including Schwann cells in PNS), and physiological condition (e.g., ion channels). Length affects total time, not speed (m/s).
Question 4 of 5
The enzyme that destroys acetylcholine is:
Correct Answer: C
Rationale: Cholinesterase (acetylcholinesterase) breaks down acetylcholine in the synaptic cleft. Epinephrine is a neurotransmitter, ‘acetylcholinase’ is not a real enzyme.
Question 5 of 5
The gray matter of the brain consists mainly of neuron cell:
Correct Answer: D
Rationale: Gray matter comprises neuron cell bodies, dendrites, and unmyelinated axons. White matter is myelinated axons.