In this chapter, human brains are treated as preeminent complex systems with consciousness assumed to emerge from dynamic interactions within and between brain subsystems. Given this basic premise, the chapter first focuses on general brain features underlying such complexity and, by implication, the emergence of consciousness. Next, it outlines some of the basic anatomy and physiology that must underpin brain dynamic behavior, thereby providing background material. The chapter illustrates three main parts of the human brain: brainstem, cerebellum, and cerebrum. It provides a tentative, but physiologically based theoretical framework for experimental observations of brain dynamics with emphasis on the large-scale (centimeter) extra cranial electric field recorded with electroencephalography (EEG). Statistical mechanics of neocortical interactions (SMNI) for human neocortex has been developed, building from synaptic interactions to minicolumnar, macrocolumnar, and regional interactions in neocortex.