Which structure in the brain is responsible for involuntary control of heart rate and breathing?

The brainstem is the structure responsible for the involuntary control of essential functions such as heart rate and breathing. It consists of three main parts: the midbrain, pons, and medulla oblongata. The medulla oblongata, in particular, plays a critical role in autonomic functions, including regulating heart rate and the rhythm of breathing. It contains vital centers that receive input from various sensors in the body to maintain homeostasis and properly respond to changes.

In contrast, while the cerebellum is involved in the coordination of voluntary movements and balance, it does not control involuntary functions like heart rate and breathing. The cerebrum is primarily responsible for higher brain functions such as thought, action, and sensory processing, whereas the thalamus acts as a relay station for sensory impulses but does not control autonomic functions directly. Thus, the brainstem is correctly identified as the region of the brain that oversees these critical involuntary functions.