Sleep

Most of us do not know how much of our time passes while we are sleeping. We sleep anytime we are bored, come home from work or class, and of course at night. One-third of our life is spent while we are asleep. Sleep can be defined as a regular, recurrent, easily reversible state of the organism that is characterized by relative quiescence and by a great increase in the threshold of response to external stimuli relative to the waking state. (116) In other words, sleep is four different cycles that are repeated throughout the night that we g...