BRPT Sleep Physiology and Neuroanatomy 2 — Questions and Answers
Question 1: According to AASM criteria, delta waves associated with N3 sleep are defined as having a frequency of:
- 0.5–2 Hz
- 0.5–4 Hz (Correct answer)
- 4–8 Hz
- 8–13 Hz
Correct answer: 0.5–4 Hz
Delta waves are 0.5–4 Hz, high-amplitude (>75 µV in frontal derivations) waves that must constitute at least 20% of an epoch to score N3.
Question 2: In the two-process model of sleep regulation, which process represents the homeostatic sleep drive that accumulates during wakefulness via adenosine buildup?
- Process C
- Process W
- Process S (Correct answer)
- Process R
Correct answer: Process S
Process S (homeostatic sleep pressure) rises during wakefulness as adenosine accumulates and dissipates during sleep as adenosine is cleared.
Question 3: Sawtooth waves seen during REM sleep are best described as:
- 0.5–2 Hz monomorphic high-amplitude waves
- 12–14 Hz spindle-shaped bursts
- 2–6 Hz triangular or notched waves maximal in central leads (Correct answer)
- 1–3 Hz biphasic K-complex-like deflections
Correct answer: 2–6 Hz triangular or notched waves maximal in central leads
Sawtooth waves are 2–6 Hz sharply contoured or triangular waves with a notched appearance, typically most prominent over central derivations during REM sleep.
Question 4: Approximately what percentage of total sleep time is typically spent in REM sleep in healthy adults?
- 5–10%
- 10–15%
- 20–25% (Correct answer)
- 30–35%
Correct answer: 20–25%
Healthy adults spend roughly 20–25% of total sleep time in REM sleep, with the proportion increasing across successive cycles.
Question 5: REM sleep atonia (muscle paralysis) is primarily mediated by which neurotransmitters acting on spinal motor neurons?
- Dopamine and norepinephrine
- Glycine and GABA (Correct answer)
- Histamine and acetylcholine
- Serotonin and adenosine
Correct answer: Glycine and GABA
Brainstem REM-on circuits hyperpolarize spinal motor neurons via glycine and GABA, preventing the enactment of dream content.
Question 6: Per AASM scoring rules, a K-complex must have a minimum duration of:
- 0.25 seconds
- 0.5 seconds (Correct answer)
- 0.75 seconds
- 1.0 seconds
Correct answer: 0.5 seconds
A K-complex must last at least 0.5 seconds and consist of a well-delineated negative sharp wave followed by a positive component, maximal in frontal leads.
BRPT Sleep Physiology and Neuroanatomy 2
According to AASM criteria, delta waves associated with N3 sleep are defined as having a frequency of: