Sleep Physiology and Neuroanatomy Flashcards

According to AASM criteria, delta waves associated with N3 sleep are defined as having a frequency of:

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.

In the two-process model of sleep regulation, which process represents the homeostatic sleep drive that accumulates during wakefulness via adenosine buildup?

Answer: Process S

Process S (homeostatic sleep pressure) rises during wakefulness as adenosine accumulates and dissipates during sleep as adenosine is cleared.

Sawtooth waves seen during REM sleep are best described as:

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.

Approximately what percentage of total sleep time is typically spent in REM sleep in healthy adults?

Answer: 20–25%

Healthy adults spend roughly 20–25% of total sleep time in REM sleep, with the proportion increasing across successive cycles.

REM sleep atonia (muscle paralysis) is primarily mediated by which neurotransmitters acting on spinal motor neurons?

Answer: Glycine and GABA

Brainstem REM-on circuits hyperpolarize spinal motor neurons via glycine and GABA, preventing the enactment of dream content.

Per AASM scoring rules, a K-complex must have a minimum duration of:

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.