The brain, an organ the size of a small head of cauliflower, resides in the skull and is the control center of the body. The brain is the most vital organ to everyday life functioning and, together with the spinal cord and peripheral nerves, makes up the central nervous system, which directs, coordinates, and regulates voluntary (conscious) and involuntary (unconscious) processes. Sensory nerves throughout the body constantly gather information from the environment and send it to the brain via the spinal cord. The brain rapidly interprets the data and responds by sending messages with motor neurons to the rest of the body.
Scientists have found that certain parts of the brain perform certain functions. The frontal lobe, where the limbic system is located, helps regulate emotions and trauma, assists with reasoning, planning, and problem solving, and is involved with some language skills. The parietal lobe aids with recognition and interpreting data, orientation, and movement. The occipital lobe is connected to visual processing, and the temporal lobe supports perception, auditory processing, memory, and speech.
Due to its important role in managing and directing all organs, systems, and body processes, the brain has several layers of protection including the skull, the meninges (thin membranes), and cerebrospinal fluid. The brain also has what has come to be called the “blood-brain barrier,” which keeps cells of the nervous system separate from cells throughout the vascular system (the rest of the body).