MSN 672 Module 3 Sleep and Anxiety
Questions and Answers Latest 2026
Internal triggers for anxiety and PTSD Ans: Thoughts,
memories, or physiological sensations (like panic or
stress hormone surges) that activate fear pathways in the
brain.
External triggers for anxiety and PTSD Ans:
Environmental or sensory cues—such as certain places,
noises, smells, or people—that remind individuals of past
trauma or danger.
Amygdala Ans: The brain structure primarily responsible
for detecting threats and initiating fear responses.
Hippocampus Ans: Links fear with memory and context,
helping differentiate safe from dangerous environments.
Prefrontal cortex Ans: Regulates (inhibits) the amygdala's
fear response; reduced activity leads to poor control of
anxiety or PTSD symptoms.
Hypothalamus Ans: Activates the autonomic nervous
system (fight-or-flight) through sympathetic activation.
Locus coeruleus Ans: Releases norepinephrine,
heightening alertness and arousal during stress.
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Thalamus Ans: Relays sensory information to the
amygdala and cortex for quick processing of potential
threats.
Ascending Reticular Activating System (ARAS) Ans:
Regulates wakefulness, alertness, and arousal.
Neurotransmitters associated with ARAS Ans:
Norepinephrine, dopamine, serotonin, histamine,
acetylcholine, glutamate, and GABA.
Norepinephrine's effect on arousal Ans: Increases
alertness and vigilance (originates from the locus
coeruleus).
Histamine's influence on ARAS Ans: Promotes
wakefulness via activation of H1 receptors.
Histamine production location Ans: In the
tuberomammillary nucleus (TMN) of the hypothalamus.
Histamine's main role in CNS Ans: To promote
wakefulness and maintain alertness.
H1 antagonists Ans: Block histamine's action, producing
sedation and drowsiness.
Orexin (hypocretin) Ans: Chemical produced by the
hypothalamus that regulates wakefulness.
Hypothalamic dysfunction and narcolepsy Ans: Loss or
dysfunction of orexin-producing neurons leads to sudden
REM sleep attacks and daytime sleepiness.
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