The hindbrain is located toward the rear and lower portion of a person’s brain. It is responsible for controlling a number of important body functions and process, including respiration and heart rate. The brain stem is an important part of the hindbrain, and it controls functions that are critical to life, such as breathing and swallowing. The cerebellum is also located here, playing a role in physical ability.
The brain stem is a structure that connects the brain to the spinal cord. Damage to this structure can be catastrophic, as it controls such things as blood pressure, heartbeat, and swallowing. It is made up of three parts: the medulla, reticular formation, and pons.
The medulla controls how and when a person’s heart beats, as well as his blood pressure, breathing, and even his ability to swallow or cough. This part of a person’s brain stem functions by itself, without relying on the person’s intentions, which is why a person’s heart beats without him making it do so. It’s also the reason people breathe even when they are focused on other things.
The reticular formation is a network of nerves important to a person’s attention or focus, as well as his response to stimuli. This part of the brain helps an individual pay attention to just one important thing, even if he’s faced with several types of stimuli at once. It blocks those less important stimuli, allowing the person to focus. For example, if a person is a potentially dangerous situation, the reticular formation blocks other stimuli, allowing him to focus solely on doing what’s needed to help him survive.
Interestingly, the reticular formation slows down when a person goes to sleep. It does not, however, stop working to block some sensory messages while allowing others through. This area of the brain is the reason many people can stay asleep despite the sounds of passing cars or creaks and groans of a house settling, yet wake to the sound of a smoke detector.
The pons is the part of the hindbrain located above the medulla. It forms a kind of bridge between the medulla and the cerebellum. This structure relays messages between the cerebellum and the cerebrum, which is part of the forebrain. It also helps control movement and plays a role in sleep.
The cerebellum is located to the rear of the brain stem. Its role involves muscle tone and posture, influences motor control, and helps a person to perform smooth, controlled movements. The cerebellum also important in coordinating the movements that people make without thinking or concentrating first, such as walking forward.