The human body is composed of cells, tissues and organs that work together in complex systems. It is a highly developed structure made up of these basic units that function well despite their complexity. Cells group together to form tissues, tissues group to form organs, and organs work in systems to perform important tasks that keep the body functioning.

1. STRUCTURE OF THE HUMAN BODY
Cells, Tissues and Organs
The human body is a complex and highly developed
structure, which works extremely well most of the time
despite its complexity. It is composed of cells, tissues
and organs. A system is a group of organs that work
together to perform certain tasks.