Unsettling simulation shows exactly what happens in your body when you vomit and people are horrified

A simulation revealing what happens internally when you throw up is causing social media users to 'almost vomit' just from watching it.

We all know what it looks like when we vomit - sitting there, our head in our hands as we stare into the abyss of the toilet bowl, questioning why we said yes to that extra shot the night before or didn't pay as close attention to the sell by date on that packet of prawns.

When you're retching that last remaining bit of acid up, you may see the contents of the night before staring back at your blood shot eyes and be able to identify what's come out of you, but do you know what's actually going on inside in your body when you're puking last night's dinner up?

What happens when you vomit?

A simulation - credited to its respective owner and shared to Instagram by account @today_knowledges - reveals what happens internally before the sick spews out of your mouth and into the toilet - or on the side of the road, a bowl or hopefully just anywhere that's not a taxi.

The video depicts the small intestine, pyloric sphincter, stomach wall and oesophagus, showing a green liquid sitting low down in the stomach. Along comes another little globule of neon green through the small intestine moving up to join the larger blob, followed by another until the stomach is full.

And that's when the retching will begin to kick in, the diaphragm and abdomen shown contracting, the vagus and splanchnic nerves sending signals down to the oesophagus and then up the vomit travels and out it comes.

The science behind vomiting

Science Focus explains that when your body senses a 'threat' - i.e. toxic chemicals such as too much alcohol or 'stress hormones in the blood, swaying motions or an upset stomach' - these chemicals and hormones are 'detected by the brain's chemoreceptor trigger zone (CTZ)'.

The inner ear is reportedly more sensitive at picking up swaying motions and the vagus nerve an upset stomach and once the CTZ picks up either of these signals, a chain reaction gets underway.

First off your mouth will produce extra saliva 'to protect your mouth and teeth from incoming stomach acid'.

Next, your diaphragm will begin to 'contract in a few short pulses' essentially in a bid to pressurize the stomach and push the sick up and out.

The glottis - located around your throat area - 'closes' to 'seal the airway' so nothing gets in or out of the lungs.

Your abdominal muscles double down on the contracting motion your diaphragm has started off, increasing pressure further to really encourage the toxicity in your body up and out.

Oh and if that wasn't all delightful enough already, your 'sympathetic nervous system raises your heart rate' so you'll end up nice and sweaty too.

Joyful - as one Twitter user said: "I think I could’ve went without knowing how this happens , I can’t stand the feeling."

"I almost vomited seeing this," another added.

Sober November anyone?