Which part of the brain relays information between other brain areas and regulates autonomic functions?

The medulla oblongata is an essential part of the brain that plays a critical role in relaying information between various brain areas and regulating autonomic functions, such as heart rate, blood pressure, and respiratory rhythms. Located in the brainstem, the medulla connects the brain to the spinal cord and contains several important nuclei that are involved in involuntary processes.

It serves as a major conduit for signals traveling to and from the brain, facilitating communication between higher brain centers and the body. This includes nerve pathways that control basic life functions essential for survival. Therefore, the medulla's functions are vital for maintaining homeostasis and responding to changes in the internal and external environment.

In contrast, the cerebellum primarily coordinates voluntary muscle movements and balance rather than directly regulating autonomic functions or serving as a relay hub. The pons, while also located in the brainstem and playing a role in regulating sleep and relaying signals to the cerebellum, is not as directly involved in autonomic regulation as the medulla. The cortex is responsible for higher-level functions such as cognition, sensory processing, and voluntary motor control, rather than regulating autonomic functions. Hence, the medulla is the most appropriate answer in this context.