Characteristics of NREM and REM Sleep

Comprehensive vocabulary flashcards covering the specific characteristics, physiological changes, and percentages of NREM and REM sleep stages based on the lecture notes.

NREM Stage I

A transitional stage between wakefulness and sleep that lasts only minutes, constitutes about $5\%$ of total sleep, and is characterized by a relaxed state with possible involuntary muscle jerking.

NREM Stage II

A sleep stage constituting $50\%$ to $55\%$ of total sleep where the person can be aroused with relative ease.

NREM Stage III

A stage composing about $10\%$ of sleep where the depth of sleep increases and arousal becomes increasingly difficult.

NREM Stage IV

The stage of greatest sleep depth, also called delta sleep, constituting about $10\%$ of sleep.

Delta sleep

Another name for NREM Stage IV, marked by difficult arousal and specific physiologic changes like slow brain waves, decreased pulse/respirations, and low body temperature.

REM Sleep

A sleep stage constituting $20\%$ to $25\%$ of sleep characterized by rapid eye movement, active encephalogram tracings, and difficult arousal.

Muscle behavior in REM sleep

The occurrence of small muscle twitching (e.g., on the face) and large muscle immobility that resembles paralysis.

Vital signs in REM sleep

Respirations are irregular or interspersed with apnea, pulse is rapid or irregular, and blood pressure increases or fluctuates.

Metabolic and Gastric changes in REM sleep

During this stage, metabolism and body temperature increase, and there is an increase in gastric secretions.

REM Sleep Cycle Progression

This stage enters from stage II of NREM sleep and reenters NREM sleep back at stage II.

Physiologic changes in NREM Stage IV

Changes include slow brain waves on an EEG, decreased blood pressure, relaxed muscles, slowed metabolism, and decreased pulse and respiratory rates.