The lower part of the brain is known as the MEDULLA, which is a Latin word meaning 'MARROW' or 'CORE'. It is located at the base of the brain stem and is responsible for controlling many of the body's involuntary functions, such as breathing, heart rate, and digestion. It also plays a role in regulating blood pressure and consciousness. The MEDULLA is composed of several nuclei that are involved in the control of motor and sensory functions.