ATI RN
Test Questions on Autonomic Nervous System Questions
Question 1 of 5
Which of the following substances is least able to cross the blood-brain barrier?
Correct Answer: D
Rationale: The blood-brain barrier (BBB) restricts large or charged substances. White blood cells are large and typically cannot cross the BBB unless it’s compromised. Water, sodium ions (via channels), and glucose (via transporters) can cross more readily.
Question 2 of 5
A channel opens on a postsynaptic membrane that causes a negative ion to enter the cell. What type of graded potential is this?
Correct Answer: C
Rationale: When a negative ion (e.g., Cl⁻) enters, the membrane potential becomes more negative, causing a hyperpolarizing graded potential (inhibitory postsynaptic potential, IPSP).
Question 3 of 5
Which cranial nerve lies in the junction between pons and medulla?
Correct Answer: A
Rationale: The abducent nerve (CN VI) emerges at the pontomedullary junction, innervating the lateral rectus muscle. The facial (VII) and vestibulocochlear (VIII) nerves emerge from the pons, while glossopharyngeal (IX) emerges from the medulla.
Question 4 of 5
Cell bodies for the motor supply of the trigeminal nerve lie
Correct Answer: D
Rationale: The motor nucleus of the trigeminal nerve (CN V) is in the pons, near the floor of the fourth ventricle (option e). The hypothalamus and cortex don’t house motor nuclei, and the midbrain contains CN III/IV nuclei.
Question 5 of 5
with regard to myotomal nerve supply
Correct Answer: D
Rationale: Elbow extension (triceps) is a C7-C8 myotome. Opponens pollicis is C8-T1, shoulder abduction is C5-C6, and plantar flexion is S1-S2.