Researchers study the parts of the brain and what each part does in order to understand where functions of the brain occur. Discoveries about brain anatomy assist medical professionals in diagnosing and treating brain disorders and tumors. There are three main divisions of the brain: the cerebrum, cerebellum and brain stem.

The cerebrum is the largest portion of the brain. It is covered in a thick layer of gray tissue called the cerebral cortex. Interior to the gray matter of the cerebral cortex is the white matter portion of the cerebrum. The white color comes from the layer of insulation called myelin that is on the neurons in this part of the brain.

The cerebrum is divided into two hemispheres that are joined by a band of nerves which allow communication between the two halves. The left hemisphere controls the right side of the body and the right hemisphere controls the left side of the body.

Each hemisphere of the cerebrum is divided into four lobes: frontal, temporal, occipital and parietal. The frontal lobes are the largest sections of the brain and make up the front portion of the cerebrum. The frontal lobes are the main thought processing center and control reasoning, problem solving, decision making, language and personality traits.

The temporal lobes are found on the sides of the brain, just above the ears. This part of the brain is responsible for short-term memory, understanding speech and recognizing sounds. Together with the frontal lobes, they identify and process smells.

The back portion of the cerebrum are the occipital lobes, which control vision. Lying interior to the frontal, temporal and occipital lobes are the parietal lobes. The parietals are the sensory processing center of the brain and are responsible for spoken language and learning.

The innermost area of the brain situated between the cerebrum and the brain stem is called the midbrain. The hypothalamus, thalamus and hippocampus reside here. This region of the brain controls emotions, and is responsible for emotional responses such as anger, happiness and sadness as well as hormones that dictate a variety of body functions.

The thalamus serves as the gateway that controls the passage of neurological information between the spinal cord and the cerebral cortex. It is also the part of the brain that keeps the body awake and alert.

The tiny hypothalamus controls body regulation functions, such as sleep, metabolism and homeostasis. It also controls the endocrine system by signaling hormone secretion via the pituitary gland, which controls growth and development. The hippocampus processes memories and helps to recall them when needed.

The brain stem is part of the hindbrain along with the cerebellum and extends down toward the spinal cord. The brain stem relays sensory information between the spinal cord and the parietal lobe, such as temperature, pain and spatial awareness. The brain stem also controls involuntary body functions.

Two structures that are part of the brain stem are the pons and the medulla. The pons controls involuntary eye functions such as blinking and tearing. Basic involuntary life functions are controlled by the medulla, including:

• breathing
• blood pressure
• heartbeat
• swallowing    

The cerebellum is part of the hindbrain and is located in the back portion of the brain behind the cerebrum. Its wrinkled, striated surface resembles a ball of yarn. This area of the brain controls balance, voluntary movements and coordination, such as learned physical skills and purposeful movements as well as fine motor activity.