ATI RN
Test Questions on Autonomic Nervous System MCAT Questions
Question 1 of 5
The fatty substance that insulates and speeds up the conduction of nerve impulses along the axon is called:
Correct Answer: B
Rationale: Myelin, produced by Schwann cells (PNS) or oligodendrocytes (CNS), insulates axons and speeds conduction. Neurilemma aids regeneration, synapse is a gap, and C is a duplicate.
Question 2 of 5
Which type of neuron is responsible for connecting sensory and motor neurons?
Correct Answer: B
Rationale: Interneurons connect sensory and motor neurons within the CNS. Motor neurons signal effectors, sensory neurons detect stimuli, and 'mixed' isn’t standard. (Q18 incomplete, assumed.)
Question 3 of 5
Saltatory conduction in myelinated axons involves:
Correct Answer: B
Rationale: Saltatory conduction is impulse 'jumping' between nodes of Ranvier, speeding transmission. Continuous is unmyelinated, slow isn’t typical, bidirectional is rare.
Question 4 of 5
The undershoot or afterhyperpolarization phase of an action potential is mainly due to:
Correct Answer: B
Rationale: Afterhyperpolarization occurs as K+ continues exiting, overshooting rest potential. Na+ influx stops earlier, Ca2+ is synaptic, Cl- minimal.
Question 5 of 5
In an electrical synapse, direct communication between neurons occurs through structures known as:
Correct Answer: B
Rationale: Gap junctions allow direct ion flow in electrical synapses. Vesicles and neurotransmitters are chemical, myelin insulates.