The nurse is assisting a neurologist with assessment of a patient with facial muscle weakness. When the neurologist asks the patient to identify different odors, which nerve is being tested?

Correct Answer: C

Rationale: Cranial nerve I (olfactory) is responsible for the sense of smell and is tested when a patient is asked to identify odors. Cranial nerves II, VIII, and X are involved in vision, hearing, and autonomic functions, respectively. Assessing the olfactory nerve is important for evaluating cranial nerve function.

Correct Answer: B

Rationale: The correct answer is B: acetylcholine. Acetylcholine is the neurotransmitter responsible for causing constriction of the pupil. When acetylcholine binds to muscarinic receptors in the eye muscles, it triggers the muscles to contract, leading to pupil constriction. Norepinephrine (choice A) and epinephrine (choice C) are both involved in the fight-or-flight response and dilate the pupils. Serotonin (choice D) does not directly affect pupil constriction.

Correct Answer: A

Rationale: The correct answer is A: encephalitis. Encephalitis specifically refers to inflammation of the brain tissues. "Meningitis" (B) is inflammation of the meninges, the protective membranes covering the brain and spinal cord. "Sinusitis" (C) is inflammation of the sinuses, not the brain. "Meningoencephalitis" (D) refers to inflammation of both the brain and meninges, but encephalitis is more specific to brain tissue. Therefore, encephalitis is the most accurate term for inflammation of brain tissues.

Correct Answer: C

Rationale: The correct answer is C: negative stain. Negative staining technique uses acidic stains which are repelled by the capsule of cryptococcus, making it visible as a clear halo around the stained cell. Gram stain (A) is used for bacterial cell wall visualization, simple stain (B) colors all cells uniformly, and fluorescent stain (D) requires a fluorescent microscope and specific dyes. Negative stain is the most effective method for visualizing cryptococcus capsules due to its unique structure and composition.

Correct Answer: D

Rationale: The correct answer is D because the peripheral nerves carry sensory input to the central nervous system by afferent fibers and motor commands away from the central nervous system by efferent fibers. This is known as the afferent-efferent division of the peripheral nervous system. Choice A is incorrect because cranial nerves (CNs) enter the brain directly, not through the spinal cord. Choice B is incorrect because efferent fibers carry motor commands away from the central nervous system, not sensory input. Choice C is incorrect because peripheral nerves are outside the central nervous system and do not carry impulses through motor fibers; instead, they carry motor commands through efferent fibers.