Why is the medulla oblongata considered part of the 'reptilian brain'?

The medulla oblongata is considered part of the 'reptilian brain' due to its role in controlling instinctual behaviors and basic life-sustaining functions. This area of the brain is involved in autonomic functions such as breathing, heart rate, and blood pressure—the fundamental processes necessary for survival.

The term 'reptilian brain' often refers to the most primitive part of the brain that is thought to govern the survival instincts and basic drives, much as they might in reptiles. This includes not only these vital autonomic functions but also instinctive responses to threats or the drive for food and reproduction. Therefore, the medulla's association with instinctual and reflexive actions aligns with the concept of the reptilian brain.

In contrast, the other options delve into functions characteristic of more advanced brain regions. Higher cognitive functions typically involve areas like the cerebral cortex, emotional responses are related to the limbic system, and motor coordination is managed by the cerebellum and other motor areas. Thus, the medulla oblongata's functions align perfectly with the concept of primal, instinctual behavior, which is why it is categorized within the 'reptilian brain.'