Organ system

group of organs that work together to perform one or more functions; collection of organs joined in structural unit to serve a common function

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.

An example of a system: the nervous system
The nervous system in its place in the body

Organs and their tissue systems change

These specific systems are widely studied in anatomy. They are present in many types of animals.