The cardiovascular system consists of the heart, blood vessels and blood. The blood vessels transport around the body. It is also responsible for transporting oxygen, nutrients, hormones and cellular waste throughout the body.
The heart is a four-chambered pump. It takes deoxygenated blood through the veins and delivers it to the lungs for oxygenation before pumping it to various arteries.
The blood enters the heart via the right atrium and is then pumped into the right ventricle. When the ventricle contracts the blood is pumped to the lungs for the exchange of oxygen and the removal of carbon dioxide.
Once this process is complete, the oxygenated blood returns to the heart via the left atrium and is then pumped into the left ventricle. When the ventricles contract the blood is pumped back into the body via the aorta (the largest artery in the body).