Anesthesia plays a vital role in the Medical and Clinical Sciences. Anesthesia enables the painless performance of medical procedures that would otherwise cause severe or intolerable pain to an un anesthetized patient, or would otherwise be technically unfeasible. Three categories of anesthesia exist: General anesthesia conceals central nervous system activity and results in unconsciousness and total lack of sensation, using either injected or inhaled drugs. Sedation suppresses the central nervous system to a lesser degree, inhibiting both anxiety and creation of long-term memories without resulting in unconsciousness.
