The Body Systems By Jack Barnett - Mould

The Muscular System Fun Fact The function of the muscular system is movement of the human body. Muscles are the only part in the body that con contract and relax and so they can move the other parts of the body. Another function is to give you posture and maintain body position. This system interacts with the skeletal system. The muscles pull the bones to let you move. Fun Fact The hardest working muscle is in your eyes. The smallest muscle is in your ear.

The circulatory system The circulatory [also called the cardiovascular] system is made up of the heart, blood vessels, and blood. The circulatory system all starts at the heart where the oxygen poor blood goes into the heart through the right atrium and into the lungs. In the lungs it gets oxygen and becomes oxygen rich blood and goes back to the heart and into the aorta. Then it goes out through the aorta and into the arteries and gives blood to all the cells in the body. This system interacts with the respiratory system by giving oxygen to the blood. Fun Fact The arteries capillaries and veins in one human body laid end to end would stretch 60,000 miles.

The Respiratory system The respiratory system is made up of the nasal cavity, lungs, trachea, bronchi, alveoli, and the diaphragm. The respiratory system function is to bring oxygen in the body and get rid of carbon dioxide. To do this the diaphragm contracts and the lungs relax to let oxygen in through the nasal cavity down the trachea. Then the trachea splits two way one to the left lung and on to the other then the oxygen travels through the bronchi to the very tips [which is only as big as a hair on your head] and into the alveoli. At the ends of the alveoli there are capillaries where the oxygen trades places with the carbon dioxide and into the blood vessels. This system interacts with the circulatory system to transport oxygenated blood to your body cells. Fun Fact Sometimes our diaphragm gets irritated and it causes an involuntary movement like a spasm and pushes air out of your mouth. We call this a hiccup!

The skeletal system The function of the skeletal system is movement, protecting of organs, structure, and the production of blood cells. The main parts in this system are bones, ligaments, tendons, bone marrow, and cartilage. Muscles interact with the bones because the muscles pull the bone so you can move. Fun Fact Like our skin, the human body's bones are also constantly worn down and re-made, to the point where every 7 years we essentially have a new bone.

The digestive system Fun Fact The function of the digestive system is to turn the food you eat into nutrients, which the body uses for energy. To do this first you need to eat, when the food is in your mouth it is dampened by the salivary glands and chewed up by your teeth. Then the tongue pushes it to your throat and muscles take it down the esophagus and into the stomach. Acids churn the food until the food is a liquid paste then it moves into the small intestine to be churned some more and takes the nutrients out and into the blood stream. Finally the pasty substance goes through the large intestine, turns into waste and exits through your anus. Fun Fact We make 1 to 3 pints of saliva a day, and in our life will make 2 swimming pools worth of saliva.

The nervous system Fun Fact The nervous system is basically a complex electrical wiring structure made up of nerves and cells called neurons that transmit signals throughout the body. Nerves are bundles of fibers that start at the brain and branch out to all the other parts of the body. The brain has many parts to the brain but here are the main ones, the cerebrum, cerebellum, brain stem, and hypothalamus. The cerebrum is the thinking part of the brain it controls the voluntary muscles. Next is the cerebellum. It controls balance, movement, and coordination [how your muscles work together]. Next is the brain stem. It connects the brain to the spinal cord and it keeps your body alive by breathing , digesting food and circulating blood. Last but not least is the hypothalamus. It controls temperature so if you’re really hot your hypothalamus will tell your pores to sweat. Fun Fact  There are more nerve cells in the human brain than there are stars in the Milky Way.

Resources Nervous System: Facts, Function and Diseases. Live Science. [cited February 13, 2015]. Available from: http://www.livescience.com/22665-nervous-system.html Respiratory System: Facts, Function and Diseases. Live Science. [cited February 13, 2015]. Available from: http://www.livescience.com/22616-respiratory-system.html Circulatory System: Facts, Function and Diseases. Live Science. [cited February 13, 2015]. Available from: http://www.livescience.com/22486-circulatory-system.html Digestive System: Facts, Function and Diseases. Live Science. [cited February 13, 2015]. Available from: http://www.livescience.com/22367-digestive-system.html Muscular System: Facts, Function and Diseases. Live Science. [cited February 13, 2015]. Available from: http://www.livescience.com/26854-muscular-system-facts- functions-diseases.html Skeletal System: Facts, Function and Diseases. Live Science. [cited February 13, 2015]. Available from: http://www.livescience.com/22537-skeletal-system.html