The definition of anesthesia and the the function of anesthesia to produce analgesia, paralysis, amnesia, and loss of consciousness was discussed. The categories of anesthesia including general, sedation, local, and nerve block was presented with examples of the use for each. The history of anesthesia beginning with use of alcohol and the opium poppy in 3400 BCE, along with cocaine, ether and nitrous oxide was shown, along with the structural formula of the most prevalent opiates, morphine and codeine.