Most people believe that we have one brain and that it’s the size of a basketball. In reality, each human has 4 brains! The other 3 consist of an inner brain in the spinal column, a brain stem, and a cerebellum housed within the skull cavity. They work together to keep your body running smoothly.

The brain is a complex organ of about 100 billion nerve cells called neurons. These neurons have an axon that communicates messages to the next neuron, then the next, and so on.

The brain controls everything your body does – how you walk, talk, breathe, think, feel, and move. It even controls your heartbeat, blood pressure, and how you taste, see, hear, smell, and touch.

Your brain is divided into two halves called “hemispheres”. Each hemisphere is divided into 4 sections called lobes. These lobes are the frontal lobe (involved with decision making), parietal lobe (involved in sensing where things are in space), occipital lobe (involved in vision), and temporal lobe (involved in smell and memory).

The inner brain sits at the first vertebrae of your spine. It consists of the medulla, pons, and midbrain. This inner brain connects to all of your sensory organs – eyes, ears, nose, mouth – as well as your movement organs – arms, legs, heart, and lungs.

The brainstem is located at the top of the spinal cord. Within it are two tiny structures called the thalamus and hypothalamus. The thalamus acts as a central hub for sensory information coming into the brain from all over the body. It then feeds that information to the appropriate part of the brain for processing. The hypothalamus controls several body functions that are critical to survival. It produces hormones that control thirst, hunger, sexual drive and function, body temperature, and even breathing rate.

The cerebellum sits inside your skull cavity right behind your brain stem. This is where all incoming sensory information (sight, hearing, touch) goes to be processed. It also houses the brain’s timing center that controls how fast your heart beats and breathing rate happens.

Now you know where all of that sensory information is processed. When something goes wrong somewhere along with these three brains, problems arise in the body. For example, headaches can stem from not getting enough oxygen to the brain. If there’s not enough blood flow, this could be due to stress or anxiety. The inner brain can also suffer from a lack of blood flow, which causes dizziness and fainting spells.