How Do the Parts of Your Brain Function?

Recall that the nervous system has two main divisions (see Figure 2.1): the peripheral nervous system (PNS) and the central nervous system (CNS). The CNS consists of the brain and the spinal cord. Our basic biological processes—such as heartbeat, breathing, and reflexes—all depend on the spinal cord. But everything we are and do depends on the brain. To truly understand how we see, hear, remember, interact with others, and sometimes experience psychological disorders, we need to understand the main structures of the brain. Table 2.2 summarizes how the major regions of the brain are organized and the important structure(s) in each part. This table is your road map to the content in this section; use it to help you remember and review this information.