Although we think of the brain as a single organ that floats in our skull all day, in reality the brain is made up of several distinct structures that have specialized jobs and that develop somewhat independently. As brain cells proliferate, they also become specialized for their future jobs as the place for making decisions in the brain. This is the process of cell differentiation. As cells become differentiated, they also must be located in the correct area: this is the process of cell migration. Once cells are in their specific area they become embedded in the physical structure as well as the functional structure of those areas (Berninger & Richards, 2002).

The image below highlights the primary structures of the brain which are needed for full functioning: the spinal cord, the medulla oblongata, the cerebellum, the midbrain, and the cerebrum.

Spinal Cord

The spinal cord connects the brain to the rest of the body.

Medulla Oblongata

This part of the brain is primarily responsible for life functions, including breathing, digestion, heart and blood vessel functioning, and swallowing. The medulla oblongata controls most of the involuntary actions that keep us alive, and damage to this part of the brain can be catastrophic.

From its position at the top of the brainstem, the medulla oblongata helps connect the automatic portion of the central nervous system to the parts of the brain that process sensory, emotional, and memory input (Berninger & Richards, 2002).

Cerebellum

The cerebellum, sometimes called the “little brain”, may be one of the smaller parts of the brain, but it contains the most neurons and plays an important role in how we interact with the world! It is a dense, butterfly-shaped organ at the base of the brain. If you place your hand on the back of your head and feel the area where your skull curves into your cervical spine, you are running your hand over your cerebellum.

While the medulla oblongata controls involuntary functions, the cerebellum coordinates voluntary functions throughout your body, particularly motor functions. It takes in sensory information from the spinal cord and uses that to manage gross and fine motor control. Your cerebellum helps to keep you standing upright and helps you coordinate your motor skills in space and time. It is essential for walking and talking, and its health plays a significant role in how well children develop coordination as they grow (Berninger & Richards, 2002; Santrock, 2013).

Normally, a cerebellum is considered essential to living a normal life; people who damage their cerebellum often experience dramatic declines in their coordination, balance, and ability to time their movements appropriately. It can be like losing control over all of your voluntary motor functions and always feeling uncoordinated. However, there have been cases reported of people who live completely normal lives without a cerebellum – if they are born that way! (Thomson, 2014)

Pons

Between the upper and lower parts of the brain is the Pons – a small area of brain that is responsible for relaying messages between the cerebellum and the cerebrum. Given what you have already learned about the function of the cerebellum, it should be no surprise that the pons is responsible for relaying information related to the voluntary functions that the cerebellum controls, as well as information about involuntary actions like sleep and respiration.

Midbrain

Sitting atop the pons is the midbrain, which is also a small area that plays an important role in relaying information around the brain, and ensuring proper functioning and communication.

Cerebrum

First, it is important to understand that the cerebrum is made up of two distinct hemispheres that mirror each other. The two hemispheres – right and left – process information from and exert control over opposite sides of the body. Your right hemisphere talks to the left side of your body, and vice versa. The main lobes of the brain are duplicated on each side, such that both the right and left hemisphere have the same areas (vision, sensory information, information processing, and speech) but the sides are complementary, not exact copies, meaning they do the same jobs but with different types of information.