Final answer:
The understanding of how the human body operates is based on the cellular level, organ system level, and the organism level. This encompasses the study of individual cells and their functions, how sets of organs work together to perform common functions, and how all that information contributes to the functioning of the whole organism.
Step-by-step explanation:
Our understanding of how the human body works is based primarily on three levels of organization: the cellular level, the organ system level, and the organism level. At the cellular level, we study how cells function individually and interact with each other. For example, knowing how a neuron sends signals to other neurons helps us understand how the brain works.
At the organ system level, we study how a set of organs work together to perform a common function. For instance, understanding how the heart and blood vessels work together helps us understand the cardiovascular system.
Finally, at the organism level, we put all this information together to understand how whole organisms work. For example, understanding the cardiovascular system helps us understand how blood gets circulated in the entire body.
Learn more about Levels of Organization