An example of a system: the nervous systemThe nervous system in its place in the body
In biology, an organ system is a group of organs that work together to perform one or more functions. Each does a particular job in the body, and is made up of certain tissues.
Organs and their tissue systems
These specific systems are widely studied in anatomy. They are present in many types of animals.
Immune system: protects the organism from outside Organisms like bacteria, viruses, fungi, and toxins (chemicals made by toxic cells) with proteins called antibodies.