The human brain is the master organ controlling every function of our body. It contains over 100 billion neurons; weighs only about two and a half to three pounds; and receives 20% of our cardiac output, 25% of our oxygen, and uses 25% of all the glucose available to our body. Its consistency is that of a soft-boiled egg, and it is precariously housed in a hard, protective skull, often making it vulnerable to damage as in the case of concussion or closed head injuries. The brain is responsible for our behavior, affect, perception, cognition, and personality. It controls how our body responds to stress and disease. It’s responsible for our body’s physiological and emotional functioning, daily maintenance, decline, repair, and recovery. When all is going well, our breathing, heart rate, body temperature, digestion, and affect promote health and a sense of well-being. When distressed, our breathing and heart rate increase, peripheral body temperature decreases, digestion slows, and affect becomes tense and reactive.