Which part of the brain is responsible for unconscious activities?

The medulla oblongata plays a crucial role in regulating several vital functions that occur without conscious thought. It is part of the brainstem and is responsible for controlling autonomic functions such as heart rate, blood pressure, and the rhythm of breathing. These functions are essential for survival and are managed automatically, without the need for conscious input, allowing the body to maintain homeostasis.

The medulla oblongata also serves as a pathway for communication between different parts of the brain and the spinal cord. It integrates sensory and motor signals, facilitating reflex actions such as coughing, swallowing, and vomiting, which again occur without conscious awareness. This makes it the correct answer for the part of the brain responsible for unconscious activities.