Migraine headaches often begin with a prodromal symptom such as nausea, loss of vision, visual aura, or other sensory hallucinations. Which of the following is believed to be the cause of such prodromes?

Correct Answer: D

Rationale: Vasospasm causing ischemia in sensory cortex areas is thought to cause migraine prodromes. TMP13 p. 629

Correct Answer: B

Rationale: Visual detail analysis occurs in the inferior ventral and medial occipital/temporal cortex. TMP13 pp. 662-664

Correct Answer: C

Rationale: Light activates transducin and phosphodiesterase, increasing cGMP hydrolysis and metarhodopsin II, but cAMP remains unchanged. TMP13 pp. 650-652

Correct Answer: C

Rationale: Photoreceptors hyperpolarize upon light activation, unlike most receptors. TMP13 p. 650

Correct Answer: A

Rationale: Circumvallate papillae are located posteriorly on the tongue. TMP13 p. 687