Brain Stem

Brain Stem

The brain stem is a central part of the human brain that connects the cerebrum with the spinal cord. It is responsible for controlling many of the body's automatic functions, such as heart rate, breathing, and blood pressure.

Anatomy

The brain stem is composed of three main structures: the midbrain, the pons, and the medulla oblongata.

Midbrain

The midbrain, also known as the mesencephalon, is the uppermost part of the brain stem. It is involved in functions such as vision, hearing, eye movement, and body movement. The anterior part of the midbrain contains the cerebral peduncles, which contain ascending and descending fibers that carry signals from the cerebrum to the rest of the body.

Pons

The pons is located below the midbrain and above the medulla oblongata. It serves as a message station between several areas of the brain, helping relay messages from the cortex and the cerebellum. Pons also plays a key role in sleep and dreaming.

Medulla Oblongata

The medulla oblongata is the lowest part of the brain stem. It acts as the control center for the function of the heart and lungs. It helps regulate many important functions, including breathing, sneezing, and swallowing.

Functions

The brain stem controls a variety of functions including:

• Breathing
• Heart rate
• Blood pressure
• Swallowing
• Digestion
• Sensation

It also plays a role in the body's sleep-wake cycle and consciousness.

Clinical Significance

Damage to the brain stem can have serious consequences because it controls functions vital to life. Brain stem stroke, tumors, and trauma can affect the brain stem, leading to conditions such as locked-in syndrome, coma, or brain death.

See Also

• Cerebellum
• Cerebrum
• Spinal cord