This site is designed to support and expand the Health Curriculum at Hillendale.

Nervous System This information will help you find out why the nervous system is the control and communication system of the body.

Contents

What is the Nervous System?

Parts of the nervous system
Neurons
Brain
Spinal Cord


Why Do I Shiver When I Am Cold
Why Do I Get A Fever When I Am Sick?

nervous system

brain

spinal cord

neurons

What is the nervous system?
     
Your
nervous system is the control and communication system of the body. Its job is to send and receive messages. Your nervous system controls all your thoughts and movements.

Parts of the nervous system

Neurons
     The cells that make up the nervous system are called
neurons. Long, stringy neurons are perfect for carrying the electrical messages that are the "language" of the nervous system.
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Brain
     The
brain is the command center of your entire body. The brain is the body's main information center. It is made of billions of neurons. The brain helps the body respond to the information it receives from the senses. The brain also processes thoughts. When you think, neurons in your brain are working.
     The brain has three main parts. The largest is the cerebrum, which controls vision, touch, and other senses. It also handles movements you have control over. Thinking takes place in the cerebrum. The cerebellum is another section of the brain. The cerebellum helps control balance and coordination. Another part of the brain is called the brain stem. The brain stem is the link to the spinal cord and it also controls digestion, breathing, and heartbeat.
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Spinal Cord
     The
spinal cord is a tube of neurons that runs up the spine and attaches to the brain stem. Information from nerves that branch out to the rest of the body goes to the spinal cord. Some messages are processed by the spinal cord but most information is sent on to the brain.
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Why Do I Shiver When I Am Cold?
     The body always works at keeping its temperature at a constant level. You probably know that this temperature is 98.6 degrees F. At this temperature the cells of the body work best.
     In the hypothalamus (a special section of the brain) there is an area that controls heat, thirst and other body functions. When you get too hot or too cold, this center alerts the rest of the body. It sends messages that either cool you off or warm you up. On a very cold day you may start shivering. The heat control center in the hypothalamus has sent a message to your muscles to move very rapidly. Work is being done by the muscles and heat is given off. When muscles shiver, two to four times more heat can be given off. The extra heat helps to keep you warm.
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Why Do I Get A Fever When I Am Sick?
     
A common cause of fever is infection. It seems that when you have an infection many factors activate the area of the brain called the hypothalamus. One important factor is the material produced at the site of the infection. These substances travel through the bloodstream to the brain and alert the body's heat control center. The center responds by making the cells work faster. The increased work raises the temperature of the body and you have a fever. The fast-working cells are able to make more antibodies to fight the infection. The fever also makes the body too hot an environment for bacteria to live in. Unfortunately, the fever also makes you feel sick.
Contents

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Digestion | Respiration | Nervous | Circulatory

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