Chapter 4 Flashcards
Consciousness
Awareness of internal and external stimuli
Sleep
A state marked by low levels of physical activity and reduced sensory awareness
Wakefulness
High levels of sensory awareness, thought, and behavior
Biological rhythms
Internal rhythms of biological activity
Circadian rhythm
A biological rhythm that takes place over a period of about 24 hours
Suprachiasmatic nucleus (SCN)
Body’s clock mechanism in the hypothalamus; axons of light-sensitive neurons in the retina provide information to the SCN based on light present to synchronize internal clock with outside world
Melatonin
Regulator of sleep-wake cycle
Pineal gland
Endocrine structure that releases melatonin, regulates various biological rhythms and immune system during sleep
Sleep regulation
Brain switches between sleep and wakefulness
Jet lag
Symptoms from mismatch between internal circadian cycles and the environment
Insomnia
Difficulty in falling or staying asleep for at least three nights over a month’s time
Rotating shift work
Work schedule that changes from early to late on a daily or weekly basis
Sleep debt
Someone who does not get sufficient sleep on a chronic basis
Consequences of sleep debt
Reduced levels of alertness and mental efficiency
Beta waves
Awake-highest frequency, lowest amplitude
NREM Sleep
Occurs as we begin to fall asleep, brain wave frequency decreases and amplitude increases, 3 stages
NREM Stage 1
Between wakefulness and sleep, slowdowns/decrease in respiration, heartbeat, muscle tension, body temp
Alpha waves
Early portion of NREM Stage 1-less variability, lower frequency, higher amplitude than beta waves
Theta waves
Farther into stage 1-lower frequency and higher amplitude than alpha waves
NREM Stage 2
Body is in deep relaxation, theta waves interrupted by sleep spindles and k-complexes
Sleep spindle
Rapid burst of high frequency brain waves important for learning and memory
K-complex
Very high amplitude pattern of brain activity from environmental stimuli
NREM Stage 3
Deep sleep, delta waves, slowed HR and respiration
Delta waves
Lowest frequency and highest amplitude
