When a group of organs work together to carry out a common task, they form an organ system. Organ systems are highly complex and are at the highest level or organization in animals. The main job of organ systems is to keep the body in a stable condition. In order to do this, organ systems often work with other organ systems in the body.
All mammals contain 11 major organ systems. The 22 internal organs of the human body are a part of these organ systems. Some organs are a part of more than one organ system.
Even though the major organ systems are present in all mammals, the organs associated with each system may vary among different species. In other cases, the same organ might be present in an organ system but carries on different functions.
All organ systems are essential to live but the nervous system is probably the most important. The nervous system consists of the brain, spinal cord, and many nerves. These structures work together so that you may do everything. The nervous system tells the rest of the body what to do. The nervous system is responsible for helping you read and comprehend the information you are reading right now.