10 facts about the brain

Head and Circuit Board

The adult brain only weighs about three pounds, but it is a powerful and complex organ.

The brain lets us think, reason, experience emotions and dream. It controls voluntary movements such as walking, talking, sitting and standing, and regulates involuntary activities such as heartbeat. It receives information through the five senses – sight, smell, touch, taste and hearing.

Here are 10 additional facts about the brain:

  1. The brain has three main parts. The cerebrum is involved in memory, thinking, feeling and problem-solving and controls movement. The cerebellum controls balance and coordination. The brain stem controls such functions as breathing, heart rate, blood pressure and digestion.
  2. The brain is divided into right and left halves. The left half controls movement on the body’s right side, while the right half controls the left side. In most people, the language area is mainly on the left.
  3. Our brains reach 90 percent of their adult size by the time we are 5 years old. Language and spatial understanding regions (location of objects in relation to the body) grow dramatically between ages 5 and 10.
  4. Our brains reach maturity when we are in our 20s, when the reasoning, planning and impulse-control areas are fully formed.
  5. The first signs of gradual decline in brain volume begin to show in ages 40 to 50. Short-term memory may be less sharp. In addition, reactions to complex stimuli, such as challenging calculations or card games, may take a little longer.
  6. From ages 50 to 70, language and vocabulary are still sharp. The ability to understand how things work, creativity and wisdom can remain strong. At age 70 and beyond, many individuals’ reasoning, creativity, language and procedural memories will remain sharp.
  7. It’s estimated that 10 percent of people age 65 and older have Alzheimer’s disease, a type of dementia that causes problems with memory, thinking and behavior. African-Americans are two times more likely to develop late-onset Alzheimer’s disease than whites and less likely to have a diagnosis of their condition.
  8. Mental disorders are brain disorders that they can be related to changes in the anatomy, physiology and chemistry of the nervous system. When the brain cannot effectively coordinate the billions of cells in the body, the results can affect many aspects of life.
  9. Common disorders include depression, anxiety, bipolar disorder, attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), posttraumatic stress disorder (PTSD) and schizophrenia.
  10. Approximately one in five adults in the U.S. experiences mental illness in a given year. African-Americans and Hispanic-Americans each use mental health services at about one-half the rate of Anglos.

Sources: Alzheimer’s Association, National Institute of Mental Health, National Institute on Aging