The nurse is assessing a patient's pupils for reactivity to light. Which cranial nerve (CN) is being tested?

Correct Answer: A

Rationale: Cranial nerve III (oculomotor) controls pupil constriction and is tested when assessing pupillary reactivity to light. Cranial nerves IV, VI, and XII control eye movement and tongue movement but are not directly involved in pupillary reflexes. Testing CN III is essential for evaluating brainstem function.

Correct Answer: D

Rationale: Neurons communicate both electrically and chemically. Electrical signals travel along the neuron's axon, while chemical signals (neurotransmitters) are released at synapses to transmit information to the next neuron. Radio-wave-like impulses are not involved in neural communication. This dual mechanism ensures efficient and precise transmission of information.

Correct Answer: D

Rationale: The correct answer is D: cardiac accelerator nerve. Preganglionic sympathetic fibers that project to the heart are part of the cardiac accelerator nerves, which increase heart rate and force of contraction. The other choices are incorrect because: A: solitary tract - involved in transmitting sensory information related to taste and visceral sensations. B: vasomotor nerve - regulates blood vessel tone and blood pressure. C: vagus nerve - part of the parasympathetic nervous system and slows down heart rate and decreases force of contraction.

Correct Answer: C

Rationale: The correct answer is C: stiff neck. Infant botulism is characterized by muscle weakness, including difficulty suckling, a limp body, and a weak cry. A stiff neck is not typically associated with infant botulism. The toxin affects the nervous system, causing muscle paralysis, but does not typically lead to neck stiffness. Therefore, choice C is the correct answer. Choices A, B, and D are incorrect because they are all common signs and symptoms of infant botulism, reflecting the muscle weakness and paralysis caused by the toxin.

Correct Answer: B

Rationale: The correct answer is B: Central and peripheral. The nervous system consists of the central nervous system (CNS), which includes the brain and spinal cord, and the peripheral nervous system (PNS), which includes all nerves outside the CNS. This division is essential for understanding the organization and functions of the nervous system. Choice A is incorrect because motor and sensory are functions, not divisions of the nervous system. Choice C is incorrect because the autonomic nervous system is a component of the PNS, not a separate part. Choice D is incorrect because the hypothalamus and cerebral are specific structures within the CNS, not the divisions of the nervous system.