Physiology Quiz: Sleep - Part 1

In spite of the importance of sleep to our mental, emotional, and physical well-being, our knowledge of the physiology of sleep is rather limited. We know from personal experience that lack of sleep leads to reduced mental alertness, diminished mental and physical performance, mood changes, and many other symptoms, all of which appear to be readily "cured" by getting "enough" sleep. Yet, how much sleep one needs is highly variable among individuals, and the reason for this variability is not at all clear. Human and animal studies are only beginning to elucidate the physiological factors and processes that are influenced by sleep deprivation. Test your basic knowledge of the physiology of sleep by taking this simple quiz.

(1) In at least one species, it has been shown that sleep deprivation causes death. This species is:

	(A) Human
	(B) Chimpanzee
	(C) Dog
	(D) Rat
	(E) Mouse

(2) An adequate amount of sleep, including rapid eye movement (REM) sleep, is essential for memory consolidation.

	True
	False

(3) Sleep deprivation reduces the effectiveness and efficiency of the immune system in combating illness.

	True
	False

(4) In humans, sleep deprivation:

	(A) has no influence on appetite.
	(B) tends to enhance appetite.
	(C) tends to reduce appetite.

(5) Two groups of individuals are vaccinated with exactly the same dose of a particular vaccine. Assume that the two groups are matched for all the relevant criteria (e.g., age, weight, etc.). One group is allowed to resume normal daily activity, however, another group is sleep deprived for one day after vaccination before resuming normal daily activity. After several weeks, the serum levels of the antibody produced against the vaccine antigen are measured in all individuals participating in the study. Which of the following will be a likely outcome?

	(A) The two groups have similar serum antibody levels.
	(B) The sleep-deprived group has a lower serum antibody level than the group that enjoyed normal sleep following vaccination.
	(C) The sleep-deprived group has a higher serum antibody level than the group that enjoyed normal sleep following vaccination.

(6) Leptin:

	(A) has no influence on appetite.
	(B) enhances appetite.
	(C) reduces appetite.

(7) Ghrelin:

	(A) has no influence on appetite.
	(B) enhances appetite.
	(C) reduces appetite.

(8) In humans, sleep deprivation:

	(A) has no influence on the circulating levels of leptin.
	(B) increases the circulating levels of leptin.
	(C) decreases the circulating levels of leptin.

(9) In humans, sleep deprivation:

	(A) has no influence on the circulating levels of ghrelin.
	(B) increases the circulating levels of ghrelin.
	(C) decreases the circulating levels of ghrelin.

(10) In humans, chronic sleep deprivation tends to be correlated with weight gain.

	True
	False

(11) In humans, chronic sleep deprivation tends to reduce the body's sensitivity to insulin, leading to a reduced ability to clear glucose from plasma.

	True
	False