Description: The medulla oblongata is the lower portion of the human brain stem. The
medulla is involved in autonomic functions such as heart rate, respiration,
blood pressure, swallowing, vomiting, and defecation.
Description: The midbrain of the human brain stem is the middle portion of the stem. It
is closely associated with the motor system pathways. Components of the
midbrain include the substantia nigra, cerebral aqueduct, and red nucleus.
Description: The pons is the upper part of the human brain stem where the cerebellum is
attached. The structure relays information between the cerebellum and
cerebrum. It has also been associated with the control of arousal and aids
in respiratory control.
