The |medulla| oblongata is the lowest part of the brainstem and serves as the site of connection between the |brain| and the |spinal cord|. Located just above the |foramen magnum| in the |skull| and in front of the |cerebellum|, the |medulla| oblongata contains a number of ~nerve~ centers which are responsible for controlling involuntary processes such as the heartbeat, breathing, and body temperature regulation. It is only about an inch (2 1/2 centimeters) wide and comprises less than one percent of the wight of the central nervous system. In spite of its small size, though, it is integral in the transmission of ~nerve~ impulses between the |spinal cord| and the higher |brain|. Many of the |nerve fibers| which pass through the |medulla| oblongata cross over, so that many impulses from the right side of the |brain| control functions on the left side of the body and vice-versa.