Medulla Oblongata

What is the medulla oblongata?

Your medulla oblongata is a part of your brainstem, which connects your brain to your spinal cord. That makes your medulla a major connection point in your nervous system. It also manages many of the most important functions of your body.

What does the medulla oblongata do?

Your medulla oblongata (med-oo-la ob-long-ah-ta), often just called the medulla, is a key part of your nervous system. It’s key not only because of its location but also because of what it controls. Some of its jobs include:

• Manages heart, circulation and breathing. Your medulla is where your cardiovascular and respiratory systems link together into a united system that controls your heart rate, breathing, blood pressure and more.
• Manages other automatic processes. These are things that your body often does without you having to think about them. Some examples include coughing, sneezing, swallowing, vomiting and maintaining your balance.
• Nerve connections. The vast majority of major nerves converge at your spine, carrying signals to and from your brain. That means those signals must pass through your medulla. Four of your 12 cranial nerves (which connect areas of your throat and tongue directly to your brain) pass through your medulla.
• Crossover point. your medulla is the location of a region called “the pyramids,” where most of the movement-related nerves in your body crisscross. That crossover is why one side of your brain almost always controls parts on the opposite side of your body.

The medulla and cranial nerves

Your cranial nerves (which come in pairs and use Roman numerals to set them apart) that pass through your medulla include the following:

• Cranial Nerve (CN) IX: Your ninth cranial nerve handles many of the functions of your mouth. These include activating the glands that make saliva (spit) and your ability to taste and feel things inside of your mouth. It also controls your gag reflex, which keeps you from accidentally choking on objects.
• CN X: Your 10th cranial nerve, known as the vagus nerve, is one of the most important nerves in your body. It connects to all the major organs from your neck to the top part of your colon, transmitting signals for your autonomic nervous system. These are signals you don’t think about, and they manage your heart rate, intestinal movements and more. This nerve also carries signals for muscles of your larynx (voice box) and the muscles you use to swallow.
• CN XI: Your 11th cranial nerve controls muscles on your neck and upper back. These muscles help you turn your head or shrug your shoulders.
• CN XII: Your 12th cranial nerve controls the muscles that you use to stick out your tongue. That makes this nerve vital for your ability to speak and swallow.

Where is the medulla?

Your medulla is the bottom-most part of your brain, connecting to your spinal cord through the foramen magnum, an opening at the bottom of your skull. Just above your medulla is your pons, which is just below the central structures in your brain.

Your medulla also separates the nerves that control muscle movement, which are on the left side, and the nerves that control certain sensations like touch, temperature or pain, which are on the right side.

What does it look like?

Your medulla is generally tube- or funnel-shaped. It’s widest at the top, where it connects to your pons.

What color is it?

Your medulla is beige or off-white with a slight pink tint.

How big is it?

Your medulla is an incredibly important structure, but it’s also very small. It’s only about 1.1 inches (3 centimeters) long, and its widest diameter is just over 0.78 inches (2 centimeters) across.

How much does it weigh?

The average adult human brain is between 2.6 and 3.1 pounds, of which your medulla accounts for about 0.5%. That means your medulla weighs between 2 ounces and 2.5 ounces (59grams to 72 grams).

What is it made of?

Like all other brain tissue, various types of white and gray brain matter and nerve cells make up your medulla. The tissue of your brain is roughly:

• 77% water.
• 11% lipids (fats).
• 8% proteins.
• 4% other.

What are the common conditions and disorders that affect the medulla?

• Aneurysms.
• Cancer.
• Concussion and traumatic brain injuries.
• Strokes or transient ischemic attacks (TIAs).
• Other rare conditions include Moebius syndrome, multiple system atrophy and progressive supranuclear palsy.

There are also a few conditions with specific names because of a stroke near your brainstem. These include:

• Wallenberg syndrome. Also known as lateral medullary syndrome, this happens with an interruption in blood flow to a side area of your medulla that damages that area. This is the most common type of stroke that affects your medulla.
• Dejerine syndrome. Also known as medial medullary syndrome, this happens when a stroke cuts off blood flow to the middle of your medulla, affecting the pyramids region where nerves crisscross.
• Bilateral medial medullary syndrome. This is an uncommon condition that combines the effects of Dejerine syndrome and Wallenberg syndrome, affecting both sides of your body.
• Reinhold syndrome. This condition, also known as hemimedullary syndrome, is extremely rare. It includes symptoms of both Wallenberg and Dejerine syndromes, but the Wallenberg syndrome is only on one side.
• Babinski-Nageotte and Cestan-Chenais syndrome. These are incredibly rare conditions that combine some of the effects of one-sided Wallenberg syndrome and Reinhold syndrome.

What are the common signs or symptoms of medulla conditions?

The symptoms of conditions affecting your medulla are most likely to look like symptoms that affect parts of your body with nerves that run through your medulla. A key difference is that with a stroke affecting your medulla, you’ll often have certain symptoms on one side of your body and others on the other side.

Some of the most likely symptoms include:

• Stroke symptoms.
• Clumsiness or lack of coordination (symptoms of ataxia).
• Headaches.
• Hoarseness (dysphonia).
• Inability to feel temperature or pain in part of your body or face.
• Jerky or uncontrolled eye movements (nystagmus).
• Nausea and vomiting.
• Paralysis (in various parts of your face or body).
• Trouble swallowing (dysphagia).
• Vision problems.

What are the common tests to check the health of the medulla?

Many tests can help diagnose conditions that affect your brain, including your medulla. Common tests include:

• Blood tests (such as those that look for immune system problems or genetic disorders).
• Computerized tomography (CT) scan.
• Electroencephalogram (EEG).
• Electromyogram.
• Magnetic resonance imaging (MRI).
• Positron emission tomography (PET) scan.
• Spinal tap (lumbar puncture).

What are the common treatments for the medulla?

Some of the treatments for conditions in your medulla are specific, as this part of your brain is so specialized. Your medulla’s location also means that surgery can be difficult or even impossible because of the risk of damaging nearby parts of your brain or spinal cord.

How can I take care of my medulla?

You can do several things to help prevent damage to your medulla or avoid conditions that affect it.

• Eat a balanced diet. Certain vitamin deficiencies, especially vitamin B12, can affect your brain, including your medulla, and cause major issues.
• Stay physically active and maintain a healthy weight. Circulatory and heart problems affect your brain, too. Stroke is an example of this, often happening because of problems in your heart. Staying active and maintaining a healthy weight can help reduce your risk.
• Wear safety equipment as needed. Injuries to your head can affect your brain seriously, causing concussions or traumatic brain injuries. Wearing safety equipment during work and play activities can protect your brain from these types of injuries.

Does the medulla control aggressive behavior?

No, your medulla doesn’t control aggressive behavior, anger or similar emotions. Those emotions rely on two other areas of your brain, particularly, your limbic system. Your medulla’s only role in aggression is how it manages your heart rate, breathing and other autonomic processes.

A note from Cleveland Clinic

Your medulla oblongata is a tiny part of your brain that’s vital to life. It acts as a relay station and helps direct nerve signals to and from various parts of your body. Without it, you couldn’t do things as simple as saying your name or as complicated as throwing or catching a ball. Knowing about your medulla oblongata can help you better understand your own body, and it can also help you take better care of your brain and nervous system health.