Although your text talks about brain centers and structures that are involved in different aspects of behavior, the best way to think of the brain is as a(n):

The answer to this question is integrated system.
Integrated system refers to a system that consist of several parts with different functions that work together as one.
Our brain consist of several parts with different function (such as memory, perception, analytical, creativity, etc) and these functions integrated with another and creating your current operating ability.