A sleep cycle comprises basically of four different stages that last for about 90-120 minutes. The first five-ten minutes when you are falling asleep some consider to be a fifth cycle others feel it is more of a transitional phase. The REM or last stages of sleep is where most of our dreams occur especiallyour most vivid and memorable dreams but dreams can occure in any of the stages of sleep. The sleep cycle repeats itself about an average of four to five times per night, but may repeat as many as seven times. We usually only remember dreams that occur closer toward the morning when they are about to wake up. Many people simply do not remember the dream they dream but all people dream.
Stages Of Sleep
The stages in the sleep cycle are organized by the changes in specific brain activity.
Stage 1: Is a light sleep characterized by Non-rapid eye movements (NREM), muscle relaxation, lowered body temperature and slowed heart rate. The body is preparing to enter into deep sleep.
Stage 2: In this stage, you are completely asleep and is characterized by relaxation of muscles and a further drop in body temperature. The body's immune system goes to work on repairing the day's damage, the endocrine glands secrete grown hormone and blood is sent to the muscles to be reconditioned. This stage
Stage 3: Your metabolic levels are extremely slow and you still remain in the NREM stage.
Stage 4: Is referred to as REM or delta sleep. In this stage occurs at about 90-100 minutes after the onset of sleepthis stage of sleep, your eyes move back and forth erratically. During this stage your blood pressure rises, heart rate speeds up, respiration becomes erratic and brain activity increases. Involuntary muscles also become paralyzed. This stage is the most restorative part of sleep. Your mind is being revitalized and emotions is being fine tuned. The majority of your dreaming occurs in this stage.