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15.1 What Are Circadian Rhythms?

1.
Female rats have an estrous cycle that determines when they are sexually receptive to a mate. This cycle repeats every ~4 days. What kind of biological rhythm is this?
  1. Ultradian
  2. Circadian
  3. Infradian
  4. Circannual
2 .
Biological rhythms can have a period of:
  1. a few hours.
  2. ~24 hours.
  3. more than 24 hours.
  4. All of these
3.
Every day, Eli’s alarm goes off at 6am. He hits snooze and usually does not wake up until 8am. The 2h difference between his alarm and when Eli wakes up is called a:
  1. phase difference.
  2. period.
  3. amplitude.
  4. phase.
4 .
Biological rhythms are regulated by:
  1. endogenous cues.
  2. exogenous cues.
  3. both endogenous and exogenous cues.
  4. neither endogenous nor exogenous cues.
5.
When laboratory rodents are shifted to live in constant darkness, they still show a 24h rhythm in their activity levels. We call their rhythm in these conditions:
  1. entrained.
  2. free-running.
  3. chronotype.
  4. photically shifted.
6 .
When laboratory rodents are shifted to live in constant darkness, they still show a 24h rhythm in their activity levels. If we were to expose an animal like this to a pulse of light in the first half of their subjective night, what would happen to their activity rhythm?
  1. Their activity rhythm would shift earlier a bit
  2. Their activity rhythm would shift later a bit
  3. Not much would happen
  4. Their rhythm would become disorganized
7.
Which of the following species show a circadian rhythm?
  1. Rats
  2. Bacteria
  3. Plants
  4. All of these

15.2 Where Are Rhythms in the Brain?

8 .
Entrainment of the biological clock by light requires which of the following?
  1. Photoreceptors
  2. Intrinsically photosensitive retinal ganglion cells
  3. Red light
  4. The lateral geniculate nucleus of the thalamus
9.
Imagine a rodent has a small stroke that destroys their bilateral SCN. What would happen to their activity rhythm?
  1. Their activity rhythm would shift earlier a bit
  2. Their rhythm would continue but would no longer entrain to changes in external light cues
  3. Not much would happen
  4. Their rhythm would become disorganized
10 .
Increased locomotor activity:
  1. increases serotonin release in the raphe nuclei.
  2. decreases serotonin release in the raphe nuclei.
  3. stimulates the SCN.
  4. stimulates intrinsically photosensitive retinal ganglion cells.
11.
Which of these people likely has the highest melatonin levels in their blood?
  1. Someone deep asleep in the middle of the night
  2. Someone wide awake in the middle of the day
  3. Someone taking a late afternoon nap
  4. Someone who just woke up in the morning
12 .
Among the Clock genes, high levels of Per and Cry will do what to CLOCK and BMAL1?
  1. High Per/Cry will suppress expression of CLOCK and BMAL1
  2. High Per/Cry will prevent CLOCK/BMAL1 from binding to Per/Cry promoters
  3. High Per/Cry will promote expression of CLOCK and BMAL1
  4. High Per/Cry will facilitate CLOCK/BMAL1 binding to Per/Cry promoters

15.3 Regulation of Sleep

13.
Jax has stayed up all night working on an essay for class. The next day, they are exhausted and fall asleep at 9 in the morning. Which process is driving them to sleep?
  1. Process C
  2. Process S
  3. The glymphatic system
  4. Metabolic wakefulness
14 .
Sleep is often measured by polysomnography. Which tool used in polysomnography measures brain activity?
  1. EOG
  2. EMG
  3. EEG
  4. EKG
15.
During which stage of sleep are frequent eye movements observed?
  1. Stage 1
  2. Stage 2
  3. Stage 3
  4. REM
16 .
During which stage of sleep is muscle activity low?
  1. Stage 1
  2. Stage 3
  3. REM
  4. All of these
17.
The flip flop switch of sleep-wake systems means that when the pontine peduncular tegmentum (PPT) is active, which system is inhibited?
  1. VLPO
  2. TMN
  3. Raphe nuclei
  4. Locus coeruleus
18 .
When a person is asleep, which brain region should be the most active?
  1. TMN
  2. Raphe nuclei
  3. VLPO
  4. Locus coeruleus

15.4 Disorders of Sleep and Circadian Rhythms

19.
What is the name of the sleep disorder characterized primarily by a failure to entrain to the 24-hour day?
  1. Narcolepsy
  2. Non-24hour sleep/wake disorder
  3. Laziness
  4. Insomnia
20 .
Which of the following is common in narcolepsy?
  1. Falling asleep at inopportune times
  2. Resolution of symptoms if the patient can set their own sleep and wake times
  3. Excessive time in NREM sleep
  4. Fewer nighttime awakenings than healthy sleepers
21.
What are things in common between people suffering from narcolepsy and delayed sleep-wake phase disorder?
  1. Excessive daytime sleepiness
  2. Both suffer primarily from too little sleep
  3. Both suffer primarily from disorganized sleep phase progression, falling into REM sleep too rapidly
  4. All of these
22 .
Sleep problems can arise from:
  1. inadequate sleep time.
  2. disorganized sleep phase patterns.
  3. inability to fall sleep at socially appropriate times.
  4. All of these

15.5 Circadian Rhythms and Society

23.
Which of the following represent good sleep hygiene?
  1. Going to bed at the same time every night
  2. Using your phone to wind down right before bed
  3. Keeping your bedroom warm
  4. Having a loud night owl roommate
24 .
What is the term for the negative health consequences of regularly keeping a different sleep schedule on weekends than weekdays?
  1. Sleep hygiene
  2. Daylight savings time
  3. Narcolepsy
  4. Social jetlag
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