Chapter 33: Rest and Sleep study guide

Chapter 33: Rest and Sleep Physiology of Sleep ○ RAS and bulbar synchronizing region control cyclic nature of sleep ○ RAS facilitates voluntary movements and cortical activities related to alertness ○ RAS relays impulses into cerebral cortex and spinal cord ○ During sleep ■ RAS receives few stimuli from cerebral cortex and body ○ Wakefulness ■ RAS activated with stimuli from the cerebral cortex from periphery sensory organs and cells ■ Pain, pressure and noise produce wakefulness via organs and cells ○ Hypothalamus ■ Control center for sleeping and waking ■ Injury causes abnormally long sleeping periods ○ Neurotransmitters ■ Involved with sleeping process ○ Excitatory neurotransmitters ■ Norepinephrine ■ Acetylcholine ■ Dopamine ■ Serotonin ■ Histamine ○ Inhibition ■ Gamma-aminobutyric acid (GABA) Circadian Rhythms ○ Exists in plants, animals, and humans ○ Full cycle every 24 hours ○ Can fluctuate (depending on rhythms) ■ Heart rate ■ Blood pressure ■ Body temperature ■ Hormone secretions ■ Metabolism ■ Performance ■ Mood ○ Circadian synchronization ■ When physiologic and psychological rhythms are high or most active → person is awake ■ Opposite → person is asleep ■ Light and dark are powerful regulators ■ Chronodisruption ■ Night Shift chronodisruption Stages of Sleep ○ Polysomnogram: EEG, EOG, and EMG ○ NREM sleep ■ 75% of total sleep ■ Stage 1 → 5% of total sleep ■ Stage 2 → 50-55% ■ Stage III and IV → 10 % each ■ PNS dominates and decreases: ● Pulse ● Respiratory rate ● Blood pressure ● Metabolic rate ● Body temperature ○ REM sleep ■ Difficult to arouse than NREM ■ 20 - 25 % of nightly sleep ■ Dreams occur during this stage ■ Increases: ● Pulse ● RR ● BP ● Metabolic rate ● Body temperature ■ Decreases: ● Deep tendon reflexes ● Skeletal muscle tone ■ REM rebound Sleep Cycle ○ Consecutively passes through NREM ○ Pattern is then reversed IV → III → II → REM → II → III + IV ○ Once returned to sleep → return to sleeping starting at stage I ○ Four or five cycles of sleep each night ○ Each cycle lasts 90-100 on average ○ More deep occurs in delta stage NREM stages III and IV in first ......................................continued.................................................