On the Function and Evolution of Sleep Essay -- Biology Essays Researc

On the Function and Evolution of Sleep If physiologists devoted the most research time to behaviors humans engaged in the most, we would probably have a full understanding of the biological purpose of residue. After all, humans, with the exception of most college students, spend one third of their lives in a somnolent state. Despite its fundamental role in human and animal life, stay is, even in an age when neuroscience has reduced many behaviors to neurological mechanisms, still quite mysterious. What processes are taking place during sleep that benefit the organism? Why spend so much time in an insensitive and vulnerable state? That these questions havent been definitively answered is really not a function of a lack of effort on the part of scientists, but rather of the difficulties inherent in studying sleep. It is easy to observe the harm that is done to a human or animal deprived of sleep. A rat prevented from sleeping will support the ability to maintain body temperature a nd die in about three weeks, showing no evidence of physiological damage (1). In humans, sleep want impairs thinking and suppresses the immune system. But why this deterioration take place is less clear, and the object of disagreeing theories. This essay will try to explain the function of sleep based on what is now known, and attempt to shed light on the reasons and mechanisms for its evolution.An investigation of the control, and perhaps the origin, of sleep might best begin with the hypothalamus, a flat, horizontal structure in the brain that is known to play an important role. Damage to the back portion of the hypothalamus causes somnolence, indicating that when intact, it sustains alertness (1). In contrast, damage to the front part indu... ...t suggests that many of the circuits employed in sensory reception and processing also function to establish and maintain memory, and that both functions cannot be achieved simultaneously. Sleep circumvents this limitation, and is thus a intumesce adapted behavior. WWW Sources1)Scientific American In Focushttp//www.sciam.com/missing.cfm 2)Sleep and Memory Evolutionary Perspectives http//bisleep.medsch.ucla.edu/SRS/publications.htm3)REM Sleep = Dreaming Only a Dream http//bisleep.medsch.ucla.edu/SRS/rosenlicht-feinberg.htm4)Birds May Refine Their Songs mend Sleeping ,Science Magazine article http//www.sciencemag.org/cgi/content/full/282/5397/2163Additional ResourcesDiscussion on Sleep Evolution ,Scientific American articlehttp//www.sciam.com/missing.cfm The Journal Sleep http//www.stanford.edu/dept/sleep/journal/