Answer: Brainstem
Step-by-step explanation:
The brain stem controls the flow of messages between the brain and rest of the body. There is no requirement of conscious mind for the basic functions of the body.
These functions are breathing, swallowing, heat rate, blood pressure. It takes place even when the person is sleepy, there is need to be awake.
These are the basic functions of the body which is required for the survival of organism.