Biology - Heart and Circulatory system

Red Blood Cells - Red Blood Cells transport the oxygen around the body.

White Blood Cells - White Blood Cells are the immune system inside you.

Plasma - Plasma is a yellow fluid which contains all the body cells and transports carbon dioxide, urea and the products of digestion.

Platelets - Platelets clot the blood.

During exercise muscles need more energy and so more glucose and oxygen need to be transported to the muscles.

To do this the heart must pump blood faster and so the heart rate increases so it allows more blood containing oxygen to reach the muscles.

The breathing rate also increases so more oxygen can enter the lungs and more carbon dioxide can be released.

Therefore exercise makes your body work harder and quicker.

The circulation system's main function is to get food and oxygen to every cell in the body but as well as being a delivery service it also collects waste such as carbon dioxide and urea to where they can be disposed from the body. 

The heart has two pumps one on the left one on the right, the right one pumps deoxygenated blood to the lungs, and picks up oxygenated blood from the lungs and brings it back to the left side of the heart which then pumps the now oxygenated blood round the rest of the body through the Aorta. 

Because the left side of your heart has to pump blood further than the right it is bigger.

All arteries except for the pulmonary artery carries oxygenated blood and always pumps blood away from the heart.

All veins except from the pulmonary vein carries deoxygenated blood and always pumps towards the heart.

All arteries excluding the pulmonary arteries carry oxygenated blood.

All veins excluding the pulmonary vein carry deoxygenated blood. 

There is also another tube that carries blood and that is the extremely small and thin capillary, Capillaries are 1mm long and is one cell thick. Capillaries is where the blood changes from oxygenated to deoxygenated blood because capillaries are found inside the organs and muscles and so it releases all the oxygen in the blood and gives it to the cell then it takes all the waste and carries it back into the veins.

Deoxygenated blood only turns into oxygenated blood in one place the capillaries in the lungs here the exact same thing happens only the capillaries loose all the waste in the blood and take in all the oxygen to make it oxygenated blood.