Brain stem

The brainstem is the rear part of the brain. It has two sections: the hindbrain, which includes the pons and medula, and the midbrain.

Though the brainstem is small, it is extremely important. The motor (movement) and sensory connections from the main part of the brain to the rest of the body pass through the brain stem. Also, from the brainstem come the main motor and sensory nerves to the face and neck. These nerves are called the cranial nerves. The brainstem controls many bodily functions(called involuntary or unconscious) of which we are not normally aware, such as breathing, heart beat, and sweating. The brainstem controls functions which are unconscious, but necessary for life.

The hindbrain consists of the pons, and the medulla oblongata; which is an extension of the spinal cord. It connects the other parts of the brain (the cerebrum and cerebellum) to the spinal cord. Its neurons are the control centre of bodily functions, such as breathing and blood pressure.

Functions of the brainstem

Conduction: All information going between the body and the cerebellum and the cerebrum must go through the brainstem.
Nerves: Cranial nerves 3–12 emerge from the brainstem. There are motor neurons in the brainstem that allow movement in the face, including speech and swallowing.
Integration: It is involved in cardiovascular system control, respiratory control, pain sensitivity control, alertness, awareness, and consciousness. Thus, brainstem damage is a serious and often life-threatening problem.