The Brain and Nervous System

The Brain and Nervous System

Discuss the text and solve the questions.

What Does the Brain Do?

The brain controls what we think and feel, how we learn and remember, and the way we move and talk. But it also controls things we're less aware of — like the beating of our hearts and the digestion of our food.

Think of the brain as a central computer that controls all the body's functions. The rest of the nervous system is like a network that sends 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. It contains threadlike nerves that branch out to every organ and body part.

What Does the Brain Do?

When a message comes into the brain from anywhere in the body, the brain tells the body how to react. For example, if you touch a hot stove, the nerves in your skin shoot a message of pain to your brain. The brain then sends a message back telling the muscles in your hand to pull away. This happens in an instant.

Poll

The brain controls all the body's functions.

• True

• False

What Are the Parts of the Nervous System?

The brain, spinal cord and nerves are the parts of the nervous system. Together, the nervous system helps different parts of our body communicate and allows our brain to control what is going on. Without the nervous system our brain wouldn’t work. It wouldn't know anything that was going on in the outside world and wouldn't be able to control our body. The human brain weighs just 3 pounds. The spinal cord is a long bundle of nerve tissue. It extends from the lower part of the brain down through spine. Along the way, nerves branch out to the entire body. Both the brain and the spinal cord are protected by bone: the brain by the bones of the skull, and the spinal cord by a set of ring-shaped bones called vertebrae.

What Are the Parts of the Nervous System?

Our bodies are incredibly clever. Sometimes we need to move so fast that our brains don't have time to think. So our body just bypasses the brain. This happens when we touch something hot. Our hand actually moves before the brain tells it to. The brain eventually finds out what is going on, but our body has done the clever thing and moved first.

Multiple Choice

Select the three parts of the nervous system.

• Brain, muscles and nerves.

• Spinal cord, brain and nerves.

• Nerves, senses and spinal cord.

• Muscles, senses and brain.

Multiple Choice

Which system does this image represent?

• The respiratory system

• The nervous system

• The circulatory system

• The excretory system

Multiple Choice

Carries messages from body to brain from the brain to body.

• Nerves

• Neuron

• Brain

• Spinal Cord

Multiple Choice

A bundle of nerves that runs along the back of a vertebrate within the spinal column.

• Nerves

• Stimulus

• Brain Stem

• Spinal cord

Did you know?

Although the brain looks like a dull grey organ, it is actually mostly water. About 80% of our brain tissue is liquid. This is why it is important to drink lots of water – if you are dehydrated, your brain will not work as well. Your brain floats in a special shock-proof fluid to stop it from getting bumped on the inside of your skull as your body moves around. Your brain is more powerful, more complex and cleverer than any computer ever built. It is constantly dealing with hundreds of messages from the world around you, and from your body, and telling your body what to do. Your brain keeps on growing until you are about 20 years old.

Did you know?

The biggest part of the brain is the cerebrum. The cerebrum makes up 85% of the brain's weight. The cerebrum is the thinking part of the brain and it controls your voluntary muscles – the ones that move when you want them to. So you can't dance or kick a ball without your cerebrum! When you're thinking hard, you're using your cerebrum. You need it to solve maths problems, read a map, and draw a picture. Your memory lives in the cerebrum – both short-term memory (what you ate for dinner last night) and long-term memory (the name of the place you went on holiday two years ago). The cerebrum also helps you reason, like when you know you need to put a bookmark in your book to remember where you stopped.

Multiple Choice

When you react to catch a dropped ruler your body reacts in this order:

• 1) muscles contract 2) eyes sense ruler move 3) message sent to brain 4) message sent to the muscles

• 1) message sent to muscles 2) muscles contract 3) message sent to brain 4) eyes sense ruler move

• 1) eyes contract 2) muscles sent to brain 3) message sense moves 4) ruler is sent to muscles

• 1) eyes sense ruler move 2) message sent to brain 3) message sent to muscles 4) muscles contract

Multiple Choice

What is the main function of the nervous system?

• clean waste from the cells
• absorb nutrients for energy
• deliver messages to the brain

Multiple Choice

Actions which are under your control

• involuntary

• voluntary

• brain

• vertebrae

Multiple Choice

Actions which are NOT under your control

• voluntary

• involuntary

• vertebrae

• brain

Multiple Choice

The brain is the ______ ______ of the body.

• nervous center
• nueropathy
• control center
• extension

Multiple Choice

Without the Nervous System, you couldn't...

• walk

• breathe

• think

• all of the above