CNS

"The central nervous system (CNS) is composed of the brain and spinal cord. The brain receives sensory information from the nerves that pass through the spinal cord, as well as other nerves such as those from sensory organs involved in sight and smell. Once received, the brain processes the sensory signals and initiates responses. The spinal cord is the principle route for the passage of sensory information to and from the brain.
Information flows to the central nervous system from the peripheral nervous system , which senses signals from the environment outside the body (sensory-somatic nervous system) and from the internal environment (autonomic nervous system). The brain's responses to incoming information flow through the spinal cord nerve network to the various effector organs and tissue regions where the target responsive action will take place. Diseases that affect the nerves of the central nervous system include rabies, polio, and sub-acute sclerosing pan-encephalitis. Such diseases affect movement and can lead to mental incapacitation. The brain is also susceptible to disease, including toxoplasmosis and the development of empty region due to prions. Such diseases cause a wasting away of body function and mental ability. Brain damage can be so compromised as to be lethal."

Anesthesia

Anesthesia is a way to control pain during a surgery or procedure by using medicine called anesthetics. It can help control your breathing, blood pressure, blood flow, and heart rate and rhythm. Anesthesia may be used to: 1. Relax you.
2. Block pain.
3. Make you sleepy or forgetful.
4. Make you unconscious for your surgery.
Other medicines may be used along with anesthesia, such as ones to help you relax or to reverse the effects of anesthesia.