Which part of the brain controls the most basic functions of the body?

The brain stem is responsible for controlling the most basic and vital functions necessary for survival, such as heart rate, breathing, blood pressure, and the swallowing reflex. It serves as a critical pathway for information traveling between the brain and the spinal cord. This part of the brain, which includes structures such as the medulla oblongata, pons, and midbrain, operates largely at an unconscious level, regulating autonomic functions without conscious thought.

In contrast, the cerebrum is involved in higher brain functions such as reasoning, problem-solving, and sensory perception, while the cerebellum plays a key role in coordination and balance. The cerebral cortex is responsible for higher-order functions, including cognition, emotion, and sensory processing. Thus, while all these structures are essential to overall brain function, the brain stem specifically governs the fundamental life-sustaining processes.