The brain is made up of many different parts, each responsible for maintaining certain processes in the body or mind. The medulla oblongata is a small area of the brain stem. Though it may be little, it’s incredibly important.
What Is the Medulla Oblongata?
The medulla oblongata is a part of your brainstem. Your brainstem is the part of your brain that connects to your spinal cord, a band of tissue that connects your brain through to your lower back.
The brainstem is one of three parts of your brain. It’s responsible for sending messages from your brain throughout your body. These messages help regulate:
- Blood pressure
- Heart rhythm
- Breathing
- Swallowing
- Hearing
- Balance
- The sleep/wake cycle
- Facial sensations
There are 12 different cranial nerves, or nerves that start in your brain. These control things like taste, facial movement, and facial sensations. The brainstem contains 10 of those 12 cranial nerves.
Where Is the Medulla Oblongata Located?
The brainstem consists of three parts: the midbrain, pons, and medulla oblongata. The midbrain is the top part of the brainstem. The pons is the middle portion. At the bottom, connecting to the spinal cord, is the medulla oblongata. Due to its location, the medulla oblongata plays a major part in your nervous system.
Despite its importance, the medulla oblongata is relatively small, only about an inch long. It’s widest at the top, where it connects to the pons, but that width is still only about 0.78 inches across.
What Does the Medulla Oblongata Do?
Each part of the brain stem has its own role. The midbrain is responsible for regulating your eye movement. The pons controls facial movements, balance, and hearing.
Medulla oblongata function includes a wide range of responsibilities, like:
- Linking together your cardiovascular system, the system that controls the heart, and your respiratory system, the system that controls breathing. Together they control your heart rate, breathing, and blood pressure.
- Managing nerve connections, as four of your 12 cranial nerves go through the medulla oblongata.
- Managing the place where your movement-related nerves crisscross.
- Managing other automatic processes such as balance, coughing, sneezing, swallowing, and vomiting.
Despite the small size of the medulla oblongata, there's a lot going on inside. The medulla oblongata parts and systems include:
- Area postrema. The area postrema detects hormones that control blood pressure, hunger, thirst, and nausea and vomiting.
- Cuneate nucleus and gracile nucleus. These nuclei receive input from sensory neurons in your body. The cuneate nucleus carries information from the upper body, not including the face, while the gracile nucleus processes information from the lower torso and lower limbs.
- Inferior olivary nuclei. The job of the inferior bolivar nuclei is to pass on signals from the spinal cord that involve learning and motor coordination. It also releases enzymes necessary for the production of certain hormones.
- Medial lemniscus. The medial lemniscus is the place where the fibers composed of the cuneate nucleus and gracile nucleus cross.
- Pyramidal decussation of the motor pathway. Also called the pyramidal tracts, this area helps control body movements including swallowing, speaking, and facial expressions.
- Reticular formation. The reticular formation is a netlike system that stretches across all three zones of the brainstem. The part within the medulla oblongata helps regulate blood pressure, heart rate, and respiration.
- Rostral ventral lateral medulla and caudal ventrolateral medulla. These two areas have different responsibilities but together create the place where your cardiovascular system and respiratory system unite.
- Solitary nucleus. Also called the nucleus of the solitary tract, this is a group of nerve cell clusters that process information from the nervous system, regulate respiration, and process taste.
- Spinal trigeminal nucleus. The spinal trigeminal nucleus processes sensations from the ipsilateral — meaning on the same side — face, like temperature, pain, and touch.
- Spinothalamic tract. The spinothalamic tract carries information about pain, temperature, or uncomfortable touch or sensations.
The four cranial nerves that pass through the medulla oblongata are cranial nerves IX, X, XI, and XII. Each has a different responsibility.
Cranial nerve IX. The ninth cranial nerve is responsible for many functions of the mouth, including:
- Activating the glands that make saliva
- Controlling your gag reflex
- Feeling things inside your mouth
- Tasting things
Cranial nerve X. Also known as the vagus nerve, the 10th cranial nerve is one of the most important parts of your nervous system. It contains the nerves of your parasympathetic nervous system, the system that relaxes your body after times of stress and danger. The jobs of the vagus nerve include:
- Transmitting signals from the autonomic nervous system, the system that controls unconscious body activities like heart rate and digestion, to the internal organs
- Carrying signals for the voice box
- Carrying signals to the muscles you use to swallow
Cranial nerve XI. The 11th cranial nerve controls your neck and upper back muscles, allowing you to shrug your shoulders or turn your head.
Cranial nerve XII. The 12th cranial nerve controls the mouth muscles that work your tongue. This allows you to speak and swallow.
Medulla Oblongata Disorders and Conditions
There are several things that can cause medulla oblongata damage and impairment. These may have serious consequences due to how valuable the medulla oblongata is to your brain function.
Stroke. A stroke occurs when the blood supply to a part of your brain is cut off. This prevents that area of the brain from getting the nutrients and oxygen it needs and leads to brain cell death. The most common type of medulla oblongata stroke is Wallenberg syndrome, a type of stroke that affects one side of the medulla oblongata. Strokes are typically treated with medication or surgery.
Brain aneurysm. A brain aneurysm is a bulge in one of the blood vessels of your brain. This bulge can rupture, causing brain bleeding and stroke. Surgery is usually needed to repair a brain aneurysm.
Brain tumors and brain cancer. There are numerous types of brain tumors. Some are cancerous and some are noncancerous, or benign. But just because a tumor is benign doesn’t mean it’s harmless. Depending on the location, a tumor can damage vital parts of your brain. Brain tumors may require surgery, radiation, and chemotherapy.
Traumatic brain injuries (TBIs) and concussions. Traumatic brain injuries, including concussions, occur when some type of impact causes your brain to smash against the inside of your skull. They’re often caused by falls or car accidents but may also be caused by impact sports. TBIs can cause many complications, including brain bleeds and seizures. Surgery may be required to fix brain bleeds.