Your psychology instructor mentioned that during a night of sleep, a person goes through cycles of light and deep sleep, while also experiencing dreams. Using a description of the stages of NREM and REM, describe a night of sleep. When you lay down at night after a long hard day, you probably think that your sleeping patterns are going to be different every night depending on what you did that day. But that’s not entirely true, sleep actually follows a pretty predictable pattern each night. Each cycle of sleep lasts about ninety minutes and contains four different stages. The type that we experience in all four stages is called NREM (non-rapid eye movement). When you are in this type of sleep, your body experiences a lot of things. In this type of sleep our heart and respiration rates are steady and slow, movements are minimal, and our brain activity and blood pressure are at their lowest in the 24-hour period. As you can see, our bodies experience a lot of things while we are asleep. It’s amazing that we aren’t even aware of it. NREM occurs in all four stages of sleep. In stage one, irregular waves with some alpha waves occur along with transition from waking to sleeping. In stage two we transfer from light to deeper sleep and experience sleep spindles which are waves with alternating periods of calm and flashes of intense activity appear. Stage three consists of deeper sleep and contains slow wave sleep, which happens when EEG shows 20% of brain waves. The final and fourth stage contains the deepest sleep and begins when 50% of waves are delta waves. After about 40 minutes of being in stage 4 sleep, delta waves begin to disappear. When that occurs, we go back through stage 3 sleep and stage two until we get back to stage 1 sleep again. As we go back into stage 1, our pathway through the night drifts into REM (rapid eye movement) sleep. During this time, our brains are highly active. Epinephrine