The Sleep Cycle

THE SLEEP CYCLE While you rest eyery night, your brain is in overdrive. The idea of sleep is simple, but what your body actually goes through is fairly complex. This process facilitates memory consolidation, aids in bodily repair, and recharges our energy levels among other things. It is one of the few experiences that everyone in the world can relate to. While the true need for sleep is still unknown, its functions are being continually recorded and studied. Brain waves dictate stages Five stages make a cycle Multiple cycles in sleep ●● 8 HOUR SLEEP the average for adults BEGIN SLEEP >> CYCLE 1 8 hr TIME ELAPSED BODY TEMPERATURE CYCLE 5 100° 98.6° 97° 7 hr ENERGY LEVEL IF AWOKEN REM PER CYCLE 100% 75% 60% 45% Non-REM sleep develops the memory of fact and knowledge, called declarative memory. 5 hr REM sleep aids in the remembrance of how to do things-like walking. TI||||IIII|||| 4 hr 15 min 4 hr CYCLE 3 AROUSAL STAGE 1 STAGE 2 STAGE 3 STAGE 4 STAGE 5 / REM Very short periods of wakefulness between cycles. Not considered a “sleep stage." Stage 1 can be considered a transition period between wakefulness and sleep. People aroused from this stage often believe that they have been fully awake. The sleeper is quite easily awakened. Respiration starts to decrease and heart rate begins to slow. Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. It is a transitional period between light sleep and a very deep sleep. Stage 4 is sometimes referred to as delta sleep because of the delta brain waves that occur during this time. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4. Stands for Rapid Eye Movement. Rate of respiration brain activity increases. Dreaming occurs because of increased brain activity, muscles become paralyzed. BRAIN ACTIVITY in a cycle 1 CYCLE wwm www mwwwymw mwwmwwww Beta waves Alpha waves Theta waves Delta waves Delta waves Delta waves Theta waves Beta waves 1 hr 30 min CYCLE 2 1 hr 3 hr 10 min 6 hr 10 min CYCLE 4