Sleep Physiology & Disorders Flashcards

What are the two main types of sleep?

Answer: REM and non-REM sleep

Sleep is broadly categorized into two main types: Rapid Eye Movement (REM) sleep and non-Rapid Eye Movement (non-REM) sleep. Non-REM sleep is further divided into three stages, progressing from light sleep to deep sleep, while REM sleep is characterized by vivid dreaming and increased brain activity. These two types cycle throughout the night, each playing distinct roles in physical and mental restoration.

Which stage of sleep is most associated with dreaming?

Answer: REM sleep

REM (Rapid Eye Movement) sleep is the stage most strongly associated with vivid dreaming. During REM sleep, brain activity significantly increases, mimicking wakefulness, and the eyes move rapidly beneath closed eyelids. This stage is crucial for cognitive functions like memory consolidation and emotional processing, often accompanied by intense dream experiences.

What is insomnia characterized by?

Answer: Difficulty sleeping and staying asleep

Insomnia is a common sleep disorder primarily characterized by persistent difficulty falling asleep, staying asleep, or waking up too early and being unable to return to sleep. This leads to insufficient or non-restorative sleep, resulting in daytime fatigue, impaired concentration, and other functional difficulties. It's not just about lack of sleep, but the struggle to achieve it.

What hormone is primarily responsible for regulating sleep-wake cycles?

Answer: Melatonin

Melatonin is a hormone produced by the pineal gland in the brain, primarily responsible for regulating the body's sleep-wake cycles, also known as the circadian rhythm. Its production increases in the evening as darkness falls, signaling to the body that it's time to sleep, and decreases in the morning with light exposure. This helps synchronize our internal clock with the external day-night cycle.

Which sleep disorder involves breathing interruptions during sleep?

Answer: Sleep apnea

Sleep apnea is a serious sleep disorder characterized by repeated interruptions in breathing during sleep. These pauses can last from a few seconds to minutes and can occur multiple times an hour, leading to fragmented sleep and reduced oxygen levels. It often results in loud snoring and excessive daytime sleepiness, and can have significant health consequences if left untreated.

What is sleep hygiene?

Answer: Maintaining behaviors that support good sleep

Sleep hygiene refers to a set of practices and habits that are necessary to have good nighttime sleep quality and full daytime alertness. It involves establishing a consistent sleep schedule, creating a comfortable sleep environment, avoiding stimulants before bed, and engaging in relaxing activities. Adhering to good sleep hygiene helps optimize the conditions for healthy, restorative sleep.

Which sleep disorder is characterized by irresistible sleep attacks during the day?

Answer: Narcolepsy

Narcolepsy is a chronic neurological condition characterized by overwhelming daytime sleepiness and sudden attacks of sleep. Individuals with narcolepsy may experience irresistible urges to sleep at inappropriate times, even after adequate nighttime sleep. Other symptoms can include cataplexy (sudden loss of muscle tone triggered by strong emotions), sleep paralysis, and vivid dreams.

What is the function of non-REM Stage 3 sleep?

Answer: Physical recovery and immune support

Non-REM Stage 3 sleep, also known as deep sleep or slow-wave sleep, is crucial for physical restoration. During this stage, the body repairs tissues, grows, strengthens the immune system, and replenishes energy stores, making it vital for overall physical health and well-being.

What external factor most influences circadian rhythms?

Answer: Light exposure

Light is the most powerful external cue (zeitgeber) that synchronizes the body's internal clock, the suprachiasmatic nucleus, with the external 24-hour day. Exposure to light, especially natural daylight, signals to the brain when to be awake and when to prepare for sleep, thereby regulating the timing of circadian rhythms.