Great Aunt Mary has always been a "lark," getting up early, working busily during the day, and then going to bed relatively early. She recently had a slight stroke, and the only thing that seems different about her is that her normal periods of sleeping and waking have changed. Now, you never know when she will get up or when she will go to bed, and she is often up half the night but sleeping during the day. Given what you have learned about sleep and waking, which one of the following brain areas might have been affected by her stroke?
A) the rubrospinal tract
B) the retinohypothalamic pathway
C) the mesolimbicstriatal pathway
D) the thalamopituitary pathway

Question

Quizplus · Accepted Answer

The retinohypothalamic pathway connects the eyes to the suprachiasmatic nucleus in the hypothalamus, which helps regulate the sleep-wake cycle. If this pathway is damaged, it can disrupt the timing of sleep and wakefulness. Since the only change in behavior noted in Great Aunt Mary is a disruption in her sleep-wake cycle, the retinohypothalamic pathway is the most likely brain area that was affected by her stroke.

Great Aunt Mary Has Always Been a "Lark," Getting Up