Which statement is incorrect concerning cerebrospinal fluid?

Correct Answer: D

Rationale: CSF is produced by the choroid plexuses but drains into venous sinuses (e.g., superior sagittal sinus), not the circle of Willis (an arterial structure). Other statements are accurate.

Correct Answer: C

Rationale: The pons (apneustic/pneumotaxic centers) and medulla oblongata (respiratory rhythm centers) regulate breathing. The hypothalamus influences autonomic functions but not directly respiration.

Correct Answer: B

Rationale: Neurons are the fundamental units of the nervous system responsible for receiving, processing, and transmitting signals. Nerves (A) are bundles of axons, not the working unit itself. The cell body (C) is a part of a neuron, not the whole unit. Neuralgia (D) refers to nerve pain, not a structure.

Correct Answer: D

Rationale: Monosynaptic reflexes involve a single synapse between the sensory neuron and motor neuron, typically seen in stretch reflexes like the knee jerk (A), biceps jerk (B), and triceps jerk (C), mediated by muscle spindles and alpha motor neurons. The abdominal reflex (D) is polysynaptic, involving multiple synapses in the spinal cord and interneurons, as it is a superficial reflex triggered by cutaneous stimulation.

Correct Answer: C

Rationale: Cones (not 'cons,' likely a typo) handle photopic (daylight) vision, not scotopic (rods do, ruling out A). Intraocular pressure is typically 10-21 mmHg (B is slightly off), myopia is corrected with concave lenses (C is correct), and the light reflex is mediated by the midbrain, not cortex (D). C is the correct answer.