Daily Archives: 22 gener 2016

THE DIGESTIVE SYSTEM

THE DIGESTIVE SYSTEM

The digestive system allows our body to get nutrients it needs. Digestion begins in the mouth. The food then travels down the oesophagus and into the stomach. The small intestine separates the nutrients from the waste. The nutrients pass to the circulatory system and travel to all the body cells. The waste passes to the large intestine and leaves the body through the anus.

THE CIRCULATORY SYSTEM

THE CIRCULATORY SYSTEM

The circulatory system sonsist of the heart, blood vessels and blood. It moves blood through the heart and around the body. Blood gives our cells the oxygen and nutrients they need. Blood also collects waste products, such as carbon dioxide, and takes them to the parts of the body which expel them.

THE RESPIRATORY SYSTEM

THE RESPIRATORY SYSTEM

The respiratory system is made up of a group of organs that help us breathe. We breathe in oxygen and breathe out carbon dioxide.

Air enters our lungs through the nose, mouth, trachea and bronchi. Oxygen then passes into our blood through the alveoli. Carbon dioxide from our blood passes into our lungs, also through the alveoli. When we breathe out, the carbon dioxide leaves our lungs.

The diaphragm is a strong muscle below the lungs which contracts when we breathe in and relaxes when we breathe out.

THE EXCRETORY SYSTEM

THE EXCRETORY SYSTEM

Our excretory system excretes waste from our body. Two organs called kidneys clean waste from our blood. The waste combines with water to make urine. Urine travels down two tubes called ureters and collects in a bag called the bladder. When the bladder is full, the urine leaves the body through the urethra.

Our body also eliminates waste through the skin. This waste is in the form of a liquid called sweat.