CBT-I Sleep Physiology & Disorders 2 — Questions and Answers
Question 1: Which neurotransmitter system is primarily responsible for promoting wakefulness and is targeted by medications like modafinil?
- Serotonin
- Dopamine (Correct answer)
- Norepinephrine
- GABA
Correct answer: Dopamine
Dopamine is a key wakefulness-promoting neurotransmitter, and modafinil works largely by blocking dopamine reuptake.
Question 2: A patient reports waking up with a dry mouth, morning headaches, and their bed partner notices loud snoring. Which sleep disorder is most likely?
- Restless legs syndrome
- Obstructive sleep apnea (Correct answer)
- Periodic limb movement disorder
- REM sleep behavior disorder
Correct answer: Obstructive sleep apnea
Obstructive sleep apnea classically presents with snoring, witnessed apneas, morning headaches, and dry mouth from mouth breathing.
Question 3: During which sleep stage does the majority of slow-wave sleep (SWS) occur in a typical night?
- First third of the night (Correct answer)
- Middle third of the night
- Last third of the night
- Equally distributed throughout
Correct answer: First third of the night
Slow-wave sleep predominates in the first third of the night, while REM sleep predominates in the last third.
Question 4: What is the term for the physiological drive to sleep that builds continuously during waking hours and dissipates during sleep?
- Circadian pressure
- Homeostatic sleep pressure (Correct answer)
- Ultradian rhythm
- Sleep inertia
Correct answer: Homeostatic sleep pressure
Homeostatic sleep pressure (Process S) accumulates adenosine during wakefulness and clears during sleep.
Question 5: A person who cannot fall asleep until 3 AM but then sleeps normally until 11 AM is most likely experiencing which condition?
- Advanced sleep phase disorder
- Delayed sleep phase disorder (Correct answer)
- Irregular sleep-wake rhythm
- Non-24-hour sleep-wake disorder
Correct answer: Delayed sleep phase disorder
Delayed sleep phase disorder is characterized by a persistent delay in sleep timing that is stable but misaligned with social demands.
Question 6: Which brain structure acts as the master circadian pacemaker in humans?
- Pineal gland
- Hypothalamus
- Suprachiasmatic nucleus (Correct answer)
- Locus coeruleus
Correct answer: Suprachiasmatic nucleus
The suprachiasmatic nucleus (SCN) in the hypothalamus is the master pacemaker that coordinates circadian rhythms throughout the body.
Question 7: What percentage of total sleep time does REM sleep typically constitute in healthy adults?
- 5–10%
- 20–25% (Correct answer)
- 40–50%
- 60–70%
Correct answer: 20–25%
REM sleep normally accounts for approximately 20–25% of total sleep time in healthy adults.
CBT-I Sleep Physiology & Disorders 2
Which neurotransmitter system is primarily responsible for promoting wakefulness and is targeted by medications like modafinil?