Which brain region is known as part of the "reptilian brain" responsible for fundamental life functions?

The brain stem is indeed known as part of the "reptilian brain" and plays a crucial role in managing fundamental life functions. This includes automatic and involuntary processes such as breathing, heart rate, and blood pressure regulation. The term "reptilian brain" refers to the most primitive part of the brain in evolutionary terms, which oversees basic survival functions that are essential for life.

The cerebral cortex, while highly advanced in terms of processing information, specializes in higher cognitive functions such as reasoning, planning, and problem-solving but does not directly manage these basic life-sustaining processes. The cerebellum is primarily involved in coordinating voluntary movements and balance, rather than the fundamental life functions. The thalamus acts as a relay station for sensory information but does not govern the vital autonomic processes that keep us alive. Hence, the brain stem correctly represents the area responsible for those essential life functions within the "reptilian brain."