The brain is the body’s command center; everything we do eating, talking, walking, thinking, remembering, sleeping is controlled and processed by the brain. As the most complex organ in the human body, the brain tells us what’s going on outside our bodies (whether we are cold or hot, for instance, or whether the person we see coming toward us is a friend or a stranger) as well as what’s going on inside our bodies (whether we have an infection or a broken bone, or whether we feel happy or sad).
The key to the body’s nervous system, the brain contains between 10 billion and 100 billion nerve cells, or neurons. Neurons combine to form the body’s nerves, thin cords that spread from head to toe and all parts in between. Neurons take in and send out electrical signals, called impulses, that control or respond to everything your body does and feels. The brain is like a very busy, high-speed post office, constantly receiving messages and sending them out all the time; it handles millions of nerve impulses every second.
- Why is blood red?
- How does the combine harvester help farmers?
- What do plasma, red blood cells, and white blood cells have to do with blood?
- How much blood is inside my body?
- What is DNA?
- Why are cells called building blocks?
- How big will I become?
- How do I grow?
- How did my life begin?
- How is the human body a living machine?
- What causes growing pains?
- What’s a charley horse?
- Which states are the biggest farm states?
- Is it easier for my face to laugh or frown?
- Which muscles are the largest, and which ones are the smallest?
- What’s an Achilles heel?
- What are muscles made of?
- Why do my knuckles sometimes make a cracking sound if I bend them?
- How is the body able to bend?
- Is there such a thing as a funny bone?
