Question

What are the responsibilities of the region of the brain highlighted below?highlighter portion is at the bottom of the brain, forming a connection between the center of the brain and the spinal cord?

Answer 1

So basically you are talking about the brain stem or medulla oblangata , which is responsible for controlling involuntary actions like breathing, beating of heart etc. this is one of the most important part of our body and if damaged can also be fatal

Answer 2

The part of the brain is Medulla oblongata.
It helps regulate breathing, heart and blood vessel function, digestion, sneezing, and swallowing. This part of the brain is a center for respiration and circulation. 
Hope it helps you