How does the brain become injured?

A: The brain is a soft, jelly-like structure that weighs about 3 pounds. It is made up of an estimated 180 billion cells; many of which are used to process information. There are an infinite number of connections between these cells, and they can be damaged or destroyed when brain cells are killed. Brain cells can die when a trauma tears brain tissue, when oxygen is unable to get to parts of the brain, or when blood is allowed to accumulate on the brain.