2I. Sleep and Wakefulness

Question 1

biological rhythm that follows an approximately one-year cycle, regulating seasonal physiological and behavioral changes

Answer 1

endogenous circannual rhythm

Question 2

a biological rhythm that follows an approximately 24-hour cycle, regulating processes like sleep-wake cycles, hormone release and body temperature

Answer 2

circadian rhythm

Question 3

a small branch of the optic nerve from the retina to the SCN, altering the SCN’s settings

Answer 3

retinohypothalamic path

Question 4

a stimulus that resets the circadian rhythm, meaning “time-giver” in German

Answer 4

zeitgeber

Question 5

rely on noise, temperature, meals, and activity to set their circadian rhythms

Answer 5

blind people

Question 6

hormone released by the pineal gland that increases sleepiness

Answer 6

melatonin

Question 7

all animals have melatonin except ___

Answer 7

sponges

Question 8

the internal timing system that regulates physiological and behavioral processes in living organisms

Answer 8

biological clock

Question 9

why is the biological clock important?

Answer 9

• synchronizes body functions with the environment
• optimizes energy use and hormone regulation
• disruptions can cause sleep, metabolic, and mental health issues

Question 10

disruption of circadian rhythms after crossing time zones

Answer 10

jet lag

Question 11

going ___, we stay awake later at night and then awaken late the next morning, already partly adjusted to the new schedule; we phase-delay our circadian rhythms

Answer 11

west

Question 12

going ___, we phase-advance to sleep earlier and awaken earlier; most people find it difficult to go to sleep before their body’s usual time and difficult to wake up early the next day

Answer 12

east