October 6, 2011

Vomiting Centre

Vomit Centre is perhaps the coolest name of any part of the human body.

It is located in the stem of your brain, in an area called the medulla oblongata. The medulla oblongata is old, meaning it is also found in the brains of other critters not so closely related to humans, such as fish. Old parts of the brain tend to do the really important stuff that animals with brains have been doing for millions of years, such as breathing and maintaining a beating heart.

The Vomiting Centre collects information from across the body and when this part of the brain becomes excited (in the neurological sense, not the 'I can't wait for the next episode of True Blood' sense) people vomit.

Signals INTO the Vomiting Centre

From other parts of the brain: You know these parts are talking to the Vomiting Centre when you want to vomit because you see someone else vomit. Or when my Nanna smells really ripe bananas and her stomach tries to empty itself.

From organs: You know organs are talking to the Vomiting Centre when you eat so much that your stomach expands and you throw up. Or when you have an intestinal blockage and you vomit.

From the inner ear: You know when your balance system is talking to the Vomiting Centre when you get get off a roller coaster feeling very dizzy, and vom.

From chemoreceptor trigger zones: These trigger zones are also in the medulla oblongata. They detect chemical abnormalities and poisons throughout the body, meaning it's chuck time.

Signals OUT OF the Vomiting Centre

Regardless of how the Vomiting Centre becomes excited (spending too long on a roller coaster, blocked intestine, being vomited on) the final action is the same: vomition.

Why does chemo = nausea and vomiting?

The way chemotherapy drugs make the body vomit isn't as straight forward as you might think. The next blog post will explain why chemotherapy makes the body vomit.

And it doesn't involve the stomach (well, not at first, as we all know the act of vomiting is ALL stomach).


  1. How interesting! looking forward to the next post explaining why it doesn't involve the stomach. i love this blog Benjiman, explains everything really well. xxx

  2. Facinating stuff Ben! I hope your vomitting centre hasn't been getting too over-excited of late....take care xo
    Sal P

  3. I think there is also vomiting receptors in the blood right?


  4. The chemoreceptor trigger zones are outside the blood-brain barrier, so they can respond to changes in the blood. The two small roads leading to vomit town for chemotherapy patients involve the chemoreceptor trigger zones detecting either increased serotonin or the actual chemotherapy drug in the blood stream.

    Is that what you meant?

  5. kind of...what I learnt is that there are three ways to trigger vomiting and that there are three major places where vomiting receptors are located, blood, intestine and one thing else, which I can't remember but know it would be on the exam. The interesting thing is, stomach does not have lots of vomiting receptors because it got lots of foreign things in it. It is what survived the strong acid environment that are considered "threat"


  6. why do the chemotherapy get side effect as an vomiting and what its mechanism

    1. Hi, I have tried to explain it as best I can in this post: http://benbbrave.blogspot.com/2011/10/chemo-vom.html