chapter 5 The demand for sleep Flashcards
(32 cards)
consciousness
refers to your level of awareness of external and internal stimuli, divided into 2 categories, Normal waking consciousness (NWC) and Altered state of consciousness (ASC)
NREM Sleep
Non Rapid Eye Movement, 3 stages NREM 1, NREM 2 and NREM 3. In each stage sleep becomes progressively deeper. It is important for restoring body functions
NREM stage 1
light stage of sleep that lasts 2-10 minutes. Movement is minimal and heart rate, breathing rate blood pressure and metabolic rate begin to decrease. Theta waves begin to replace alpha waves.
NREM Stage 2
Lasts 20-30 minutes. Heart rate, breathing rate and metabolic rate continue to decrease.
Sleeper still receptive to loud noises and external stimuli.
Theta waves
NREM stage 3
Deep sleep. It lasts around 20 - 40 minutes, however decreases in length over the course of the night. Heart and breathing rate stabilise, muscles are relaxed and eyes show little movement.
delta waves
REM Sleep
Rapid eye movement. Quick movements of the eyes under the eyelids
The brain and internal organs are very active, although REM sleep is a very deep type of sleep
Heart rate, breathing rate and metabolic rate all become irregular during REM sleep.
REM sleep is helpful for restoring brain functions . Like NREM sleep, the amount required differs across the lifespan.
Beta waves occur becuase neurons in the brain act as they are awake
Altered state of consciousness (ASC)
a person experiences reduced awareness, ASC incudes naturally occurring eg sleep, daydreaming or induced eg being drunk
Normal waking consciousness (NWC)
when you are awake and aware of your thoughts, feelings and perceptions from internal and external environment
psychological construct
sleep is a psychological construct as it is something we believe to exist, as we can measure its effects but cannot directly measure or observe it
Electroencephalograph - EEG
An EEG is a device that Detects, Amplifies and Records the Electrical activity of the neurons in the brain. It produces a recording of brainwave patterns which can be analysed and interpreted
Electromyograph - EMG
The EMG is a device that Detects, Amplifies and Records the Electrical activity of muscles of the body.
Electro-oculargraph - EOG
An EOG is a device that Detects, Amplifies and Records the Electrical activity of the muscles responsible for controlling eye movements. An EOG provides an indication of the changes in eye movement that occurs through a night’s sleep
brain waves
BATD
Beta, Alpha, Theta, Delta
Amplitude
the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position. if the waves are tall = high amplitude
frequency
the number of waves, more bunched up = higher frequency
Beta
Have a low amplitude and a high frequency . they occur when we are awake and alert and ‘beta like waves’ occur during rem sleep because the brain is active
Alpha
Have a low medium amplitude and Medium high frequency. Occur in a deeply relaxed state like when you are falling asleep
theta waves replace alpha waves in stage 1 NREM
Theta
Have a medium high amplitude and a low medium frequency. theta waves occur in early or light sleep which is stage one NREM
delta
High amplitude and low frequency occur in deep sleep Stage 3 NREM
Circadian rhythms
Are biological patterns that follow a 24 hour cycle, They are influenced by zeitgebers, The sleep wake cycle is a circadian rhythm
Zeitgebers
‘time givers’, external cues that can influence changes in the sleep wake cycle, such as light, Temperature, and eating and drinking
Suprachiasmatic nucleus (SCN)
A cluster of neurons in the hypothalamus that regulates the body’s circadian rhythms, particularly the sleep– wake cycle, using information about the intensity and duration of light received from the eyes via the optic nerve
pineal gland
located deep within the forebrain that secretes melatonin, which regulates body rhythms and the sleep–wake cycle
melatonin
Melatonin A hormone secreted by the pineal gland that causes drowsiness and helps to regulate the sleep–wake cycle