How does farting work?

[Simple Linctus]

Not to be too crude - but how is it that you can fart without soiling yourself? You would think that opening the sphincter muscle in your arse would let stuff other than gas out.

Or is the truth even more horrific and it's letting solids and liquids out at the same time as the gas?

[Duckster]

Facts on Farts.

Bon Appétit!

[aldiboronti]

The answer is that you do soil yourself, it's simply that most times it's unnoticeable. As well as gas farts produce a fine spray of fecal matter.

[Chimera]

Originally Posted by Duckster

Facts on Farts.

"skatole" for the lolz.

[cmyk]

On top of the fact that fecal matter is shooting out of your anus when you fart, those who smell it, are, in a way, tasting it too; which molecules are absorbed in your olfactory bulb then become a part of you.

Keep that in mind next time you smell one.

And with that, I hereby nominate this thread to be entered into the Eternal Vaults of Posterity.

[pravnik]

F*ckin' farting! How does it work?

[cmyk]

Originally Posted by pravnik

F*ckin' farting! How does it work?

It's a miracle, yo.

[PlainJain]

I have a related question: so what makes the noise? Is it the sphincter opening and slamming shut?

[cmyk]

Originally Posted by PlainJain

I have a related question: so what makes the noise? Is it the sphincter opening and slamming shut?

Like a thin wind through the reeds, your flatus vibrates your buttcheeks at an appropriate Hertz and amplitude as to be audible.

If you desire to let one loose in silence, find an inconspicuous way to spread your buttcheeks apart. But make sure they're really apart, otherwise the frequency will raise, and it'll be a high-pitched squeak.

I speak from experience.

[digs]

Originally Posted by Simple Linctus

How does farting work?

Quite well, thank you.

[LawMonkey]

Originally Posted by cmyk

Like a thin wind through the reeds, your flatus vibrates your buttcheeks at an appropriate Hertz and amplitude as to be audible.

If you desire to let one loose in silence, find an inconspicuous way to spread your buttcheeks apart. But make sure they're really apart, otherwise the frequency will raise, and it'll be a high-pitched squeak.

I speak from experience.

Not that I'd know, but I imagine that if you needed to squat down to tie your shoe at about the same time you needed to fart, you'd be able to do it just about silently with a modicum of muscle control. Just sayin'.

[Elendil's Heir]

A previous thread that may be of interest: http://boards.straightdope.com/sdmb/...d.php?t=595744

[cmyk]

Originally Posted by LawMonkey

Not that I'd know, but I imagine that if you needed to squat down to tie your shoe at about the same time you needed to fart, you'd be able to do it just about silently with a modicum of muscle control. Just sayin'.

And, likewise, not that I'd know, but when seated one might be able to release one buttcheek from the pressure of sitting, pinning the other in place, and with a bit of finesse, concentration and precisely timed muscle control, can let slip the dogs of war unnoticed.

[cochrane]

Originally Posted by cmyk

And, likewise, not that I'd know, but when seated one might be able to release one buttcheek from the pressure of sitting, pinning the other in place, and with a bit of finesse, concentration and precisely timed muscle control, can let slip the dogs of war unnoticed.

Ah, the famous one-cheek sneak.

[AaronX]

Originally Posted by cmyk

And, likewise, not that I'd know, but when seated one might be able to release one buttcheek from the pressure of sitting, pinning the other in place, and with a bit of finesse, concentration and precisely timed muscle control, can let slip the dogs of war unnoticed.

It can be troublesome:

A family brings their elderly mother to a nursing home. The nurses bathe her and set her in a chair at a window.

After a while, she slowly starts to lean over sideways in her chair. Two attentive nurses immediately straighten her up. Again, she starts to tilt to the other side. The nurses rush back to put her upright. This goes on all morning.

Later, the family arrives and asks, "Are they treating you all right?"

"It's pretty nice," the old woman replies. "Except they won't let you fart."

[Mona Lisa Simpson]

Originally Posted by AaronX

It can be troublesome:

A family brings their elderly mother to a nursing home. The nurses bathe her and set her in a chair at a window.

After a while, she slowly starts to lean over sideways in her chair. Two attentive nurses immediately straighten her up. Again, she starts to tilt to the other side. The nurses rush back to put her upright. This goes on all morning.

Later, the family arrives and asks, "Are they treating you all right?"

"It's pretty nice," the old woman replies. "Except they won't let you fart."

Sorry, my apologies. We will let your Grandma lean next time. We thought it was the Seroquel.

[si_blakely]

Originally Posted by cmyk

On top of the fact that fecal matter is shooting out of your anus when you fart, those who smell it, are, in a way, tasting it too; which molecules are absorbed in your olfactory bulb then become a part of you.

Keep that in mind next time you smell one.

What your nose detects are some of the volatile compounds (at very low concentrations, especially sulphides) that have evaporated off the surface of the material in question and diffused around the room. The aroma of something is not the same as the thing itself - just ask anyone who manages to eat durian.

When you expel flatus, mostly you are getting rid of ordinary air containing volatiles from the fecal matter it has passed over and through. Yes, there may be a small spray of some fecal matter, but underclothes capture that.

Si

[Colophon]

One aspect that hasn't been touched on but I think is key is that what we in polite circles refer to as the rusty sheriff's badge, balloon knot or brown tea-towel holder actually has two sphincters, the inner and the outer.

You can release the outer door, as it were, but as long as the inner one stays closed there will be no mass exodus of poop. Think of it like an airlock.

[lieu]

Originally Posted by cmyk

If you desire to let one loose in silence, find an inconspicuous way to spread your buttcheeks apart. But make sure they're really apart, otherwise the frequency will raise, and it'll be a high-pitched squeak.

I tried that once. First there was just the rush of wind, then it cried out "Mama." It sounded just like when Nova dropped that doll in the cave in Planet of the Apes.

[toofs]

I love a good fart. They are quite literally a universal source of amusement on this little planet of ours. What I am curious about is the difference in scent that occurs depending upon what you eat. I have on a few well planned occasions consumed carefully selected foods with the intention of destroying my buddies. Two scoops of whey protein powder, a few eggs and a can of chili all washed down with a few beers and let me tell you, I possess an evil so putrid it should be registered somewhere. Other times, I have huge 'air' farts that are all bark, no bite.

What gives?

[Shark Sandwich]

Originally Posted by cmyk

Like a thin wind through the reeds, your flatus vibrates your buttcheeks at an appropriate Hertz and amplitude as to be audible.

This was almost...poetic.

[Slow Moving Vehicle]

Slight hijack, but I thought the OP's question was neatly answered by the title of the very next thread: "A question of dog responsibility". Always works for me.

[kayaker]

Originally Posted by Simple Linctus

Not to be too crude - but how is it that you can fart without soiling yourself?

You can? Dammit!

[Jake]

Originally Posted by cmyk

Like a thin wind through the reeds, your flatus vibrates your buttcheeks at an appropriate Hertz and amplitude as to be audible.

If you desire to let one loose in silence, find an inconspicuous way to spread your buttcheeks apart. But make sure they're really apart, otherwise the frequency will raise, and it'll be a high-pitched squeak.

I speak from experience.

It's not your buttcheeks that vibrate, it's your anus. Or butthole if you will.

[Jake]

Also, farts smell so deaf people can appreciate them too!

[Michael63129]

Originally Posted by toofs

I love a good fart. They are quite literally a universal source of amusement on this little planet of ours. What I am curious about is the difference in scent that occurs depending upon what you eat. I have on a few well planned occasions consumed carefully selected foods with the intention of destroying my buddies. Two scoops of whey protein powder, a few eggs and a can of chili all washed down with a few beers and let me tell you, I possess an evil so putrid it should be registered somewhere. Other times, I have huge 'air' farts that are all bark, no bite.

What gives?

The smell is produced from compounds in food, or compounds created by bacteria and digestion, especially nitrogen and sulfur compounds; thus protein-rich foods are notorious for smelly farts, as are sulfur-rich foods (not always though; beans are high in protein but don't make smelly farts):

The odor of farts comes from small amounts of hydrogen sulfide gas and mercaptans in the mixture. These compounds contain sulfur. Nitrogen-rich compounds such as skatole and indole also add to the stench of farts. The more sulfur-rich your diet, the more sulfides and mercaptans will be produced by the bacteria in your guts, and the more your farts will stink. Foods such as cauliflower, eggs and meat are notorious for producing smelly farts, whereas beans produce large amounts of not particularly stinky farts.

[Machine Elf]

Originally Posted by Jake

It's not your buttcheeks that vibrate, it's your anus. Or butthole if you will.

Oh, I will.

[KarlGauss]

The Anal Sphincter.

[KneadToKnow]

Originally Posted by Mona Lisa Simpson

We thought it was the Seroquel.

More likely the Taco Bell.

[Lukeinva]

Originally Posted by Jake

Also, farts smell so deaf people can appreciate them too!

He who smelt it dealt it.

[cochrane]

Originally Posted by Lukeinva

He who smelt it dealt it.

He who denied it, supplied it.

[ArmenE]

Originally Posted by cmyk

On top of the fact that fecal matter is shooting out of your anus when you fart, those who smell it, are, in a way, tasting it too; which molecules are absorbed in your olfactory bulb then become a part of you.

Keep that in mind next time you smell one.

This is inaccurate. It's absorbed into mucus, that's true, but then, after interacting with olfactory receptor neurons in the olfactory epithelium (not the olfactory bulb), and inducing a temporary configurational change in olfactory receptor proteins, the odorants are let go and cleared out (probably down your throat and eventually, out the backside)

[cmyk]

Originally Posted by Machine Elf

Oh, I will.

Me too.

[cmyk]

Originally Posted by ArmenE

This is inaccurate. It's absorbed into mucus, that's true, but then, after interacting with olfactory receptor neurons in the olfactory epithelium (not the olfactory bulb), and inducing a temporary configurational change in olfactory receptor proteins, the odorants are let go and cleared out (probably down your throat and eventually, out the backside)

Oh, you fardantics.

But still, ewww gross! All I know is that someone's fart molecules are entering my face, and proceeding through my head. Perhaps to even find a home there.

[Arrendajo]

Originally Posted by Jake

It's not your buttcheeks that vibrate, it's your anus. Or butthole if you will.

I question this, but I will not ask for a cite. I question it because one time I shaved my ass, and the only disconcerting thing about having a shaved ass was that I could no longer sneak out farts like I used to. It seems I removed the little bit of material from between my cheeks that gave a bit of breathing room to vented gases, and it was definitely my cheeks that were vibrating; I can neither confirm nor deny at this point whether my anus was also vibrating.

[Leo Bloom]

Originally Posted by ArmenE

This is inaccurate. It's absorbed into mucus, that's true, but then, after interacting with olfactory receptor neurons in the olfactory epithelium (not the olfactory bulb), and inducing a temporary configurational change in olfactory receptor proteins, the odorants are let go and cleared out (probably down your throat and eventually, out the backside)

Wait, I'm farting someone else's farts?

[ArmenE]

Originally Posted by Leo Bloom

Wait, I'm farting someone else's farts?

That's right. It's turtles all the way down.

[born too late]

Originally Posted by ArmenE

That's right. It's turtles all the way down.

Turdles?

[si_blakely]

Well, when you think about it, some of your fart has been produced by gut bioflora farting out gases, so...

[kayaker]

I call it a sling blade.

[Hyperelastic]

Originally Posted by cmyk

On top of the fact that fecal matter is shooting out of your anus when you fart, those who smell it, are, in a way, tasting it too; which molecules are absorbed in your olfactory bulb then become a part of you.

As my old college roommate once said, smelling a fart means that someone's "shit molecules" are entering your snoot.

[Reebevoli]

Mrs Reeb read that people fart on average, 30 times a day. Since then her first of the day is announced as 'one'. After I get home from work, 8 hours later, her very next flatus is followed by 'two'. It still creases me up.