What's on the inside?
- The skin acts as a protective cover over your body. It keeps germs and dirt out and it keeps moisture in.
- Our bodies are supported by a skeleton. It protects important organs.
- The blood/circulatory system
- The heart pumps blood around the body; this can be felt as a pulse as well as a heart beat. Exercise increases your heart beat.
- The heart is a muscle and is the size of a person's fist.
- The digestive system
- Important parts of the digestive system include the gullet, stomach, intestines and liver.
- Food and drink are taken in through the mouth and pass down through the gullet (or oesophagus) to the stomach. Food is churned up in the stomach and broken down to some extent.
- Food then passes into the intestine, which is a very long tube. Here the food is further broken down into very small particles which can pass through the wall of the intestine into the blood. The food now can be used to produce energy.
- Some food continues down the intestine and is passed to the outside when a person goes to the toilet.
- The liver has about 500 functions including helping in the digestion of fats, storing vitamins, and cleaning blood of poisons
- The breathing system
- Air is breathed in through the nose. It passes down the windpipe, into the bronchi and then to the lungs. Your ribs protect many of these parts.
- The air you breathe in contains a lot of oxygen. In the lungs this oxygen passes into the blood and can then be brought to every part of the body. Carbon dioxide from the body passes into the blood in the lungs also and is got rid of from the body when you breathe out.
- Breathing rates increase with exercise because your muscles need more oxygen when you are exercising.