Your circulatory system is one of the most important systems in your body. Without the circulatory system your body would be unable to receive the nutrients it needs. It also is an important part of getting rid of any toxins or byproducts that your body makes during the day. Your body would not even be able to defend itself against viruses and other invaders that could harm you without the circulatory system. The circulatory system can be broken down into three main parts: the heart, the circulatory vessels and the blood.
The heart is the most integral part of the circulatory system. The heart is like the motor that keeps everything running. Located left of the center of your chest, the heart is am muscle that acts as a pump to move blood throughout the body. As the hearts beats, the right side of the heart siphons in blood that has been spent of oxygen and needs to be sent to the lungs. The left side of the heart pumps in the newly oxygenated blood from the lungs and sends it to the rest of the body. It sends the blood using a series of tubes called vessels.
The two main vessels of the circulatory system are arteries and veins. Their are also supporting vessels called capillaries. When the heart beats, it sends oxygen rich blood from the lungs, through the heart, and into the body through arteries. These arteries are located throughout the body and carry the oxygen rich blood to all the muscles and tissues that need it. The arteries have special walls that can respond to hormones and other chemicals that are released in the body. This allows the walls to expand or contract, controlling the pressure and flow of the blood as it passes through the system.
Branching off from these large arteries are smaller blood vessels called capillaries. The capillaries deliver the oxygen rich blood from the arteries to the actual tissues themselves. This allows oxygen and other nutrients direct access to keep the body healthy.
Once the oxygen and nutrients have been removed from the blood by the tissues, the blood is sent back to another major vessel called veins. The veins run back towards the heart sending the spent blood back into the heart. The heart then beats sending the blood back to the lungs to be re-stocked with oxygen.
The substance that flows through the circulatory system is called blood. Blood is like the car of your body. It is able to transport all types of body chemicals, nutrients, waste and cells throughout your body. In the blood are two types of blood cells, red and white. The red blood cells are responsible for haemoglobin which takes on oxygen and carries it to the tissues of the body. The white cells are more responsible for keeping your body healthy by helping to fight off infection.