1
,
, Test Bank for Sleep Disorders
Physiological Basis of Sleep
Question 1
Which of the following brain structures is primarily responsible for regulating the circadian
rhythm?
A) Thalamus
B) Hippocampus
C) Suprachiasmatic Nucleus (SCN)
D) Amygdala
E) Cerebellum
Correct Answer: C
Explanation: The Suprachiasmatic Nucleus (SCN) of the hypothalamus is the master circadian
pacemaker in mammals, receiving light input from the retina and synchronizing internal biological
rhythms with the external light-dark cycle.
Question 2
During which stage of sleep do K-complexes and sleep spindles predominantly occur?
A) N1 (NREM Stage 1)
B) N2 (NREM Stage 2)
C) N3 (NREM Stage 3/Slow-Wave Sleep)
D) REM (Rapid Eye Movement) Sleep
E) Wakefulness
Correct Answer: B
Explanation: K-complexes and sleep spindles are characteristic EEG waveforms of NREM Stage 2
sleep. K-complexes are high-amplitude, biphasic waves, while sleep spindles are bursts of
oscillatory activity, both thought to play roles in sleep protection and memory consolidation.
Question 3
Which neurotransmitter is most closely associated with promoting wakefulness and inhibiting REM
sleep?
1
, A) Acetylcholine
B) Serotonin
C) Dopamine
D) Histamine
E) Adenosine
Correct Answer: D
Explanation: Histamine, particularly through its H1 receptors, plays a crucial role in maintaining
wakefulness and alertness. Antihistamines, which block H1 receptors, often cause drowsiness as a
side effect.
Question 4
Paradoxical sleep is another name for which sleep stage, characterized by vivid dreaming and
muscle atonia?
A) N1 (NREM Stage 1)
B) N2 (NREM Stage 2)
C) N3 (NREM Stage 3/Slow-Wave Sleep)
D) REM (Rapid Eye Movement) Sleep
E) Delta Sleep
Correct Answer: D
Explanation: REM sleep is often called paradoxical sleep because the EEG activity resembles that of
wakefulness (low voltage, mixed frequency), yet the individual is deeply asleep and experiences
muscle atonia (paralysis) and vivid dreams.
Question 5
Which of the following hormones is primarily secreted during the dark phase and plays a
key role in regulating the sleep-wake cycle?
A) Cortisol
B) Growth Hormone
C) Melatonin
D) Thyroid-Stimulating Hormone (TSH)
E) Adrenaline
2
,
, Test Bank for Sleep Disorders
Physiological Basis of Sleep
Question 1
Which of the following brain structures is primarily responsible for regulating the circadian
rhythm?
A) Thalamus
B) Hippocampus
C) Suprachiasmatic Nucleus (SCN)
D) Amygdala
E) Cerebellum
Correct Answer: C
Explanation: The Suprachiasmatic Nucleus (SCN) of the hypothalamus is the master circadian
pacemaker in mammals, receiving light input from the retina and synchronizing internal biological
rhythms with the external light-dark cycle.
Question 2
During which stage of sleep do K-complexes and sleep spindles predominantly occur?
A) N1 (NREM Stage 1)
B) N2 (NREM Stage 2)
C) N3 (NREM Stage 3/Slow-Wave Sleep)
D) REM (Rapid Eye Movement) Sleep
E) Wakefulness
Correct Answer: B
Explanation: K-complexes and sleep spindles are characteristic EEG waveforms of NREM Stage 2
sleep. K-complexes are high-amplitude, biphasic waves, while sleep spindles are bursts of
oscillatory activity, both thought to play roles in sleep protection and memory consolidation.
Question 3
Which neurotransmitter is most closely associated with promoting wakefulness and inhibiting REM
sleep?
1
, A) Acetylcholine
B) Serotonin
C) Dopamine
D) Histamine
E) Adenosine
Correct Answer: D
Explanation: Histamine, particularly through its H1 receptors, plays a crucial role in maintaining
wakefulness and alertness. Antihistamines, which block H1 receptors, often cause drowsiness as a
side effect.
Question 4
Paradoxical sleep is another name for which sleep stage, characterized by vivid dreaming and
muscle atonia?
A) N1 (NREM Stage 1)
B) N2 (NREM Stage 2)
C) N3 (NREM Stage 3/Slow-Wave Sleep)
D) REM (Rapid Eye Movement) Sleep
E) Delta Sleep
Correct Answer: D
Explanation: REM sleep is often called paradoxical sleep because the EEG activity resembles that of
wakefulness (low voltage, mixed frequency), yet the individual is deeply asleep and experiences
muscle atonia (paralysis) and vivid dreams.
Question 5
Which of the following hormones is primarily secreted during the dark phase and plays a
key role in regulating the sleep-wake cycle?
A) Cortisol
B) Growth Hormone
C) Melatonin
D) Thyroid-Stimulating Hormone (TSH)
E) Adrenaline
2
