The Nervous System You and your brain

What is the Nervous System If you think of the brain as a central computer that controls all bodily functions, then the nervous system is like a network that relays messages back and forth from the brain to different parts of the body. It does this via the spinal cord, which runs from the brain down through the back and contains threadlike nerves that branch out to every organ and body part.

How the Nervous System Works The nervous system depends a lot on tiny cells called neurons. The brain has billions of them, and they have many specialized jobs. For example, sensory neurons take information from the eyes, ears, nose, tongue, and skin to the brain. Motor neurons carry messages away from the brain and back to the rest of the body. All neurons, however, relay information to each other through a complex electrochemical process, making connections that affect the way we think, learn, move, and behave.

Intelligence, learning, and memory. At birth, the nervous system contains all the neurons you will ever have, but many of them are not connected to each other. As you grow and learn, messages travel from one neuron to another over and over, creating connections, or pathways, in the brain. It's why reading seemed to take so much concentration when you first learned but now is second nature: The pathways became established.

Your senses None of your senses: What you see What you hear What you taste What you touch What you smell Would be useful without the processing that occurs in the brain.

The Brain The brain serves as the center of the nervous system. The brain takes in information, processes information, decides what to do with that information, and tells the body to do it.

Brainy Facts Human brain operates 24 hours a day. An adult human brain is about 3 lbs. or 1,300 g. of gooey, slimy, wobbly gelatinous stuff. The brain is 75% water. The brain represents @ 2% of total body weight. An elephant brain weights 6,000 g. A cat brain weights 30 g.

Let’s watch some brainpop! Log onto www.brainpop.com Username kyrene Password brainpop Watch the movies titled: Brain Nervous System Neurons Dreams

Brainpop: Brain Sleep

Right or Left hand? Which hand you use to do the following tasks: Write your name Use Scissors Kick a ball Step onto a mat Look through a tube Cup your ear to listen to a whisper Listen through a wall

Which side of the brain do you rely on most? Did you find that you used mostly ones side of your body for all the tasks? The brain is divided into 2 halves called hemispheres. The right side of your body is controlled by the left side of your brain. The left side of your body is controlled by the right side of your brain.

Which one are you? Left Brain or Right Brain Left Side Looks at parts, then the whole Completes tasks in order Deals with reality Likes rules Logical Sees cause & effect Controls feelings Prefers talking & writing Very planned Right Side Looks at wholes; then parts Completes tasks randomly Deals with imagination Does not like rules Analogical Looks for patterns and similarities Free with feelings Prefers drawing & manipulating objects Spontaneous

Are you a left brain person or a right brain person?

The Brain The brain is enclosed and protected by the bones of the skull, or cranium. There are three parts of the brain: A. Medulla- Control center for involuntary activities: breathing, heartbeat, circulation & digestion. B. Cerebrum- Higher processes: thinking, learning, imagination, and the five senses. C. Cerebellum- Physical coordination; Controls voluntary muscle movement, maintains balance and muscle tone.

Sensory Memory Takes in information long enough to decide whether to: Move it to short term memory Act on it Discard it as extra information ***lasts only 2-3 seconds

Short-term Memory Sometimes called the working memory. Information only stays here for a short period, depending on how often you use it.

Long-term Memory Used to recall important and unimportant information for very long periods. The more you use information in short-term, the more likely it is to become long term. Holds: Skills Facts Birthdays Faces

Sometimes the nervous system works so quickly that a person may not even be aware that the brain, spinal cord, and nerves are at work. When quick responses are required, the nerve connection to the brain can be bypassed. To save time, the spinal cord takes over the brain’s job and instructs the body to move. These quick-moving messages and responses along the nervous system are called reflex actions or reflexes.