The brain connects to the spine and is part of the central nervous system (CNS). The various parts of the brain are responsible for personality, movement, breathing, and other crucial processes that keep people alive.

An average adult brain weighs 3 pounds and is composed of 60% fat, with water, protein, carbohydrates, and salt accounting for the other 40%. The brain is an organ made up of neural tissue. It is not a muscle.

The brain is made up of three main parts, which are the cerebrum, cerebellum, and brain stem. Each of these has a unique function and is made up of several parts as well.

Keep reading to learn more about the different parts of the brain, the processes they control, and how they all work together. This article also looks at some ways of maintaining a healthy brain.

Cross-section of the brain.Share on Pinterest
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The brain is the command center that controls the nervous system. When people damage different parts of the brain, they may notice changes in their personality, movement, vision, sleep, and other important bodily functions.

A traumatic brain injury or stroke are some conditions that cause brain death. A person can technically be alive after brain death, but they will never regain consciousness. To sustain life, doctors place the person on artificial life support to keep the heart and lungs working. The heart has a separate electrical system from the brain, which is why it still beats for a short while after brain activity stops.

Doctors will carry out many tests before reaching a diagnosis of brain death. Brain death is a traumatic experience for everyone involved. It can be particularly difficult to come to terms with the diagnosis, especially if a person can see their loved one breathing and showing signs of life.

The brain is composed of three main structures, the cerebrum, cerebellum, and brain stem.

The brain sends chemical and electrical signals throughout the body to regulate different biological functions and sense environmental changes. The brain communicates with the majority of the body through the spinal cord. To do this, it uses billions of nerve cells throughout the CNS.

Click on the BodyMap above to interact with a 3D model of the brain.

The cerebrum is the front part of the brain and includes the cerebral cortex.

This part of the brain is responsible for many processes, including:

  • initiating and controlling movement
  • thinking
  • emotion
  • problem-solving
  • learning

The cerebrum is responsible for personality. If a person experiences trauma to the cerebrum, in particular the frontal lobe, their friends and family may notice changes in their demeanor, mood, and emotions.

Learn more about the cerebrum here.

Cerebral cortex

The cerebral cortex covers the cerebrum and has many folds. Due to its large surface area, the cerebral cortex accounts for 50% of the brain’s total weight.

The cerebral cortex has four lobes:

  • Frontal lobe: This area is responsible for language, motor function, memory, personality, and other cognitive functions.
  • Temporal lobe: The temporal lobe contains the Wernicke area, which is responsible for understanding language. It also processes memories and emotions and plays a major part in hearing and visual perception.
  • Parietal lobe: The parietal lobe processes what a person sees and hears. It also interprets other sensory information.
  • Occipital lobe: The occipital lobe interprets visual information and contains the visual cortex.

The cerebral cortex is made of grey matter, which is where the brain processes information. It also has ridges (gyri) and folds (sulci). The folds and ridges accommodated the rapid brain growth humans experienced over years of evolution.

The right side of the cerebral cortex, or hemisphere, controls the left side of the body, and the left hemisphere controls the right side of the body. Each hemisphere communicates with the other through the corpus callosum, which is a bridge of white matter.

The cerebellum, or “little brain,” is tucked underneath the cerebrum at the back of the head. It regulates balance and learned movements, such as walking and fastening buttons, but it cannot initiate movement.

Because the cerebellum is sensitive to alcohol, people will experience problems with balance and walking when they consume too much. Recent research suggests the cerebellum may also play a role in learning and decision-making.

The cerebellum is an ancient part of the brain, and the cerebral cortex grew on top of it as humans evolved.

Learn more about the cerebellum here.

The brainstem is made up of the midbrain, pons, and medulla. It connects the cerebrum to the spinal cord.


The midbrain is responsible for several important functions that include hearing and movement. It also helps formulate responses to environmental changes, which include potential threats.


The pons enables a range of bodily functions, such as the production of tears, blinking, focusing vision, balance, and facial expressions. 10 cranial nerves arise from the pons. These connect to the face, neck, and trunk.


The medulla regulates biological functions that are essential for survival, such as heart rhythm, blood flow, and breathing. This part of the brain also detects changes in blood oxygen and carbon dioxide levels. Reflexive responses such as vomiting, swallowing, and coughing also originate from the medulla.

Brain health is just as important as physical health. Keeping the brain healthy could offset memory loss and also help prevent other chronic conditions such as diabetes.

Actions a person can take to improve their brain health include:

  • stopping smoking
  • preventing or managing high blood pressure
  • maintaining a healthy weight
  • keeping cholesterol levels within a healthy range
  • getting enough sleep
  • staying socially active
  • managing blood sugar levels
  • reducing alcohol consumption

Learn about the best foods for maintaining brain health here.

The brain is the most complex structure in the body. It is made up of three major areas: the cerebrum, cerebellum, and brain stem.

It controls critical biological processes that are crucial for survival, such as breathing and temperature regulation.

Maintaining a healthy brain not only offsets memory loss as people age, but also helps protect against chronic conditions such as diabetes.