What is Anesthesia?
To remove the pain during operations, usually by putting the patient to sleep, is called anesthesia. And the substance that is used is called anesthetic and nitrous oxide (laughing gas) and halothane are probably the best known.
They work by damping down the action of the brain until consciousness is lost, and then the patient becomes relaxed. Then muscle relaxant injections are used for further relaxation. It becomes easier and painless for the person who has to get operated. Anesthesia is normally induced by an injection into the bloodstream and then maintained by gases.
Also, minor dental operations are performed under intravenous anesthesia or relaxation without gas. There is another method of doing anesthesia by injecting into the nerves of the part that has to be operated (local anesthesia) so that no pain is felt.
The dentist's injection into the angle of the jaw is one type of "nerve block".
Similar injections are also made around the lower spinal cord rendering the whole of the lower half of the body numb. This is "epidural" anesthesia which is used in childbirth. Very special facilities are required for this and not all women wish to have no feeling during such an exciting time.
Just because of the recent improvements in anesthetics, most of the benefits of the modern surgery have become possible.