The human body is an incredibly complex organism that carries out the life processes common to living things and has a highly developed ability to make decisions and to carry out actions. No other living thing has developed to the same extent, as humans. The human body has a number of body systems that help the body to maintain itself, grow, develop and reproduce. There are also a number of organs that are key to the health and maintenance of the body.

At birth the human brain consists of in the region of 1,000 billion nerve cells and is a key part of the central nervous system.
- The brain stem and cerebellum ensures the body function such as circulation and breathing are maintained.
- The cerebrum is much larger and processes information received via the senses via the nervous system.
The heart is part of the circulatory system and and is a large muscle that pumps blood around the body. The heart is effectively two pumps working together: one pumping blood from the body to the lungs; the other pumping blood from the lungs and around the body.

The lungs are part of the respiratory system and allow the body to breathe in air to take from it the oxygen that the body needs. They then allow us to exhale the waste gases that are produced during the actual process of cellular respiration.

The liver is linked to the digestive system and produces bile, a green liquid used in the process of digestion. It also stores glucose, vitamins and minerals as well as removing poisons that are in the blood.
The kidneys are the main cleaning system within the body and are responsible for filtering the blood and removing waste substances. They also remove water from the digestive system.