what are principles of organisation in the human body?

Cells are the basic building blocks of all living organisms. A tissue is a group of cells with a similar structure and function. Organs are aggregations of tissues performing specific functions. Organs are organised into organ systems, which work together to form organisms. The digestive system is an example of an organ system in which several organs (with their different types of cells and tissues) work together to digest and absorb food. All the organ system in the body (circulatory, lymphatic etc.) form a human