Download The Nervous System

Mohammad Moiz
Health Science 3H – Period 6/7
The Nervous System
The nervous system performs many functions in our body that we take for
granted; for example, tasting, smelling, seeing, hearing, feeling pain or pleasure
or any sensation would all be impossible without a nervous system. The human
nervous system is divided into two parts: the central nervous system and the
peripheral nervous system. The central nervous system consists of the brain and
the spinal cord. The brain is an extremely important organ that uses information
from nerves to coordinate the body’s actions. It is divided into many lobes
including the frontal lobe, parietal lobe, occipital lobe and the temporal lobe.
Different parts of the brain have different functions, for example the cerebrum
controls the voluntary muscles in the human body. The peripheral nervous
system consists of the neurons that take information to and from the central
nervous system. Overall, the nervous system is extremely important as humans
cannot exist without it.
The brain is an incredible wonder in human life. In appearance, it has
many grooves and folds and weighs about three pounds. The brain functions by
using information from nerves to coordinate bodily actions. The brain is
protected by bone of the skull. It is also cushioned by meninges and fluid called
cerebrospinal fluid. The brain works hand in hand with the spinal system of the
central nervous system. The spinal cord is basically a long bundle of nerve
tissue. It is about eighteen inches long in length and almost an inch think. The
spinal cord is protected by the bones of the vertebrae and is also cushioned by
meninges and the cerebrospinal fluid. Along the spinal cord, various nerves
branch out that form the peripheral nervous system.
The peripheral nervous system is made up of nerves and sends
messages from the brain to the rest of the body. It consists of two types of
neurons: sensory neurons and motor neurons. The function of sensory neurons
is to send messages to the brain. These neurons usually connect to the brain
through the spinal cord. Motor neurons deliver messages from the brain to all
the muscles and glands of the human body. The peripheral nervous system is
also divided into the sympathetic and the parasympathetic nervous system. The
sympathetic nervous system prepares the body to react to an extreme situation
while the parasympathetic nervous system reverses these changes when the
situation is back to normal.
Overall, the nervous system does so many things that we often don’t even
realize its working. For example, when we touch a hot surface and quickly pull
back, this is a perfect example of the nervous system at work. The brain, spinal
cord, and nerves work together to make the nervous system work smoothly. The
importance of the nervous system cannot be emphasized enough because it so
valuable; therefore it’s important to learn about it and understand how it works.
Mohammad Moiz
Health Science 3H – Period 6/7
Works Cited
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Silver Spring in Maryland and Falls Church in Virginia. Web. 10 May 2010.
<http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/PNS.html>.
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<http://library.thinkquest.org/5777/ner1.htm>.
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