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What is the Medulla Oblongata?

The medulla oblongata controls vital body functions such as respiration.
A human brain. The medulla oblongata is part of the brain stem, in dark purple at the bottom.
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  • Written By: Mary McMahon
  • Edited By: O. Wallace
  • Last Modified Date: 27 March 2014
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The medulla oblongata is a structure found in the brains of vertebrate animals, including humans. This structure controls a number of autonomic functions, including respiration and blood pressure, making it a very critical part of the brain. Damage to the medulla oblongata can be fatal, as the patient will be unable to breathe, swallow, or perform other basic motor functions without assistance. This structure is also believed to be the key to how general anesthesia works, as the anesthetics depress the medulla oblongata so that it cannot function as it normally would.

This region of the brain is located at the bottom of the brainstem, the structure which connects the brain and spinal cord. The medulla oblongata sits directly on top of the spinal cord, below the area of the brainstem known as the pons. In cross section, this region can be seen as a small bulge in the brain stem which is designed to accommodate a number of important nerves.

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In addition to regulating breathing and blood pressure, the medulla oblongata is also involved with cardiac function, various bodily secretions, swallowing, and reflexes. The functions regulated by the medulla oblongata take place at all hours of the day without any need for input from the rest of the brain. The medulla oblongata is also involved in the response to certain stimuli, creating reflexive responses which are designed to keep the body functioning. The ability to respond automatically to certain stimuli is critical to survival, as is the independent regulation of necessary functions like breathing and swallowing.

People who experience brain damage can still have functioning bodies, as long as the medulla oblongata is working. Damage to the medulla oblongata can result in the need for a ventilator or other supportive equipment to keep the body working. Depending on the nature of the damage, it may be possible to recover, or the patient may be considered to be brain dead or in a persistent vegetative state from which there is no possibility of recovery. When life support is withdrawn, the body will cease to function.

A variety of drugs and medications can cause changes in the function of the medulla oblongata, which can sometimes result in physical states which resemble death. Opiates and alcohol can both cause dysfunction until the body is able to express these substances, and in cases of overdose, it is possible to die because this area of the brain is not able to function normally. Sedatives can cause similar effects, as can hypothermia and coma.

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Discuss this Article

anon355506
Post 10
KoiwiGal
Post 9

One of the interesting things about this part of the brain is that it's present is basically all vertebrates, from crocodiles, to fish, to humans.

For this reason it's often referred to as the "reptilian brain" and apparently many reptiles do have a much larger medulla oblongata than other vertebrates do.

croydon
Post 8

@anon319394 - It's very difficult to tell how much brain damage a person has, or how much they have recovered, particularly if a patient isn't at a hospital with the latest in brain imaging software.

There have been plenty of cases where someone has been taken off life support and continued breathing and it might be that the brain damage wasn't as bad as the doctors originally thought, or it might be that the brain recovered slightly or adjusted, or it might be that the medulla is damaged enough to not work properly, but still works a little bit.

I think it can be quite sad in these cases where the medulla oblongata still functions, because most of the time the patient is still basically brain dead and will never open their eyes, but they will linger for days or longer and their loved ones will suffer for it.

Mor
Post 7

This is one of the reasons that anesthesiologists are paid so much and considered to be such an important part of the operating theater, when it appears that they don't really do all that much. If you are given too much anesthetic you could die or suffer permanent damage to the medulla oblongata. Because even though they often hook people up to a respirator during surgery, they only put you on a heart-lung machine (which can keep your circulation going when your heart stops) if they are going to deliberately operate on your heart. But, if your medulla oblongata is depressed too much, your heart will stop and it would be very difficult to get it going again.

Being able to monitor and prevent injury to the medulla oblongata is one of the many things an anesthesiologist must do during an operation.

anon319394
Post 6

But how does the medulla continue in the rare instances when a person survives being unplugged from the respirator?

Gallimaufry
Post 2

Given the importance of the medulla oblongata, it is of course vital that it have a sufficient supply of oxygenated blood. The anterior spinal artery, posterior inferior cerebellar artery, and branches of the vertebral artery supply this blood.

jwal33
Post 1

Heroin is an especially dangerous threat to the medulla oblongata. When someone overdoses on this drug, the slowing activity of the heroin in the brainstem respiratory center causes breathing to stop and can result in death. If left without respiration for too long, the brain's activity is ceased to the point of a vegetative state.

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