Brain

The brain is a pinkish-grey, wrinkled organ that fills the skull — looking, for all the world, like a huge walnut. It is hard to believe, from its appearance, that this ugly lump of jelly contains the mechanisms of thought, perception, will, and consciousness, that it is the seat of our personality. Its 100,000 million nerve cells, each with an average of 100,00 connections from other neurons, makes the human brain the most complicated and least understood object in the known universe. The vertebrate brain is the large anterior portion of the central nervous system . The "cranial vault" of the skull encases the brain in most vertebrates. In invertebrates, the enlarged and specialized anterior ganglion of the central nervous system is often referred to as a brain, although not all scientists regard it as a true brain.

Sedation

Sedation is the act of calming by administration of a sedative. A sedative is a medication that commonly induces the nervous system to calm. The process of sedation has two primary intentions. First, sedation is recommended to allow patients the ability to tolerate unpleasant diagnostic or surgical procedures and to relieve anxiety and discomfort. Second, sedation for uncooperative patients may expedite and simplify special procedures that require little or no movement. Additionally, sedation is often desirable to diminish fear associated with operative procedures. Sedation is typically used for common diagnostic tests that require prolonged immobilization such as magnetic resonance imaging (MRI) and computed axial tomography (CAT) scanning. Some cases that require sedation may also necessitate the use of analgesics to decrease pain associated with a procedure or test.