brainstem

The brainstem is one of the most ancient parts of the brain, evolutionarily speaking—it developed very early and is found in all vertebrates, not just humans. Located at the base of your brain and connecting it to the spinal cord, it is responsible for the most fundamental functions necessary for life. It is composed of three main parts: the midbrain, the pons, and the medulla oblongata, each with specific roles but all working together seamlessly.

The brainstem does not handle complex thought or conscious decision-making; instead, it controls automatic processes like breathing, heart rate, blood pressure, digestion, sleep-wake cycles, swallowing, and even blinking. It is the part of your brain that keeps you alive without you having to think about it!

It also acts as a major relay station for most nerve signals traveling between the brain and the body. Information from many senses (such as sight, sound, and touch) passes through the brainstem before being sent to other parts of the brain for processing. Similarly, motor commands from the brain travel down through the brainstem to reach muscles throughout the body.

Because it is so vital, damage to the brainstem—whether from injury or disease—can have devastating consequences, potentially leading to paralysis, coma, or death. Doctors often assess brainstem function in patients with severe head injuries to determine the extent of damage and the prognosis. So, while you might not consciously think about your brainstem, it is working tirelessly behind the scenes to keep you functioning every single moment of your life.