The "full" Feeling after digestion - Physiology or Psychology??

[mooeypoo]

The thread subject might not EXACTLY be what I mean but it was the best way I see to summerize my question.

 

I've noticed that whenever someone finishes a big meal, he emmediately (or within a few minutes usually) needs to "evacuate" himself to the bathroom.

It's clear to all that the human body does not digest solid food at such a quick period of time.

 

So I had an argument with some friends of mine about the cause.

 

Is this happening so fast because of a psychological reaction (like the reaction people have to running water and the desire to pee)

OR

Is this purely physical - to "remove" the 'remains' of whatever has been digested from the last meal.

 

If it is the second one, then why is this also happening to people who are eating lunch? their previous meal was the previous NIGHT, surely the food has been digested long before they started eating the current meal...

 

Also, that "FULL" feeling you have after you eat something - is that also physical? Or is that psychological? If you eat something you really really like - will you also feel full at the same ammount of time it'll take you to feel full while eating something you don't really like eating?

 

Sorry if that sounds.. err.. gross but well, it's still a bodily function so deal.

 

hehe I'd really like a response, my friends are threatening a bet poll and although I'm not the betting type, some of them might lose some big sum of money of it

 

thanks heaps

 

~moo

[fafalone]

I know you hate brief answers... but "both"

[mooeypoo]

You're mean

 

 

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Can you pleaaaaaaase explain though? which of them is both? the feeling / the "running to the bathroom" part...?

or.. maybe direct me to a site that would save you the troubles of explaining hehe

 

~moo

[Neurocomp2003]

yeah i'd have to say both....

cuz i get munchies all the time..and my stomach sometimes tells me its full but my brain tells me to eat or munch on something.

But sometimes the stomach is hungry.

 

So your bathroom situation is probably the same, you get chemical single set to your brain when your full and you need to um do bowel movement ...but becasue of the regularity of this...sometimes your brain just tells you to do it anwyays. even if you ain't got anything to shat out

[mooeypoo]

So what controls it? The "full" feeling? And if it's physical, why isn't the stomache just SHUTS close - instinct or something - why does it allow for more and more food if it CANT really sustain it?

[Pinch Paxton]

I've noticed that whenever someone finishes a big meal, he emmediately (or within a few minutes usually) needs to "evacuate" himself to the bathroom.

 

 

If food takes 24 hours to digest, and you eat at around the same time every day then that will happen.

[Neurocomp2003]

well ...presumably the stomach(specifically the sphincter)

cannot shut permanently when you full...else what happens if it gets stuck? you won't be able to eat which i hope is anevolutionary thing. Also lots of fluid there so i doubt it could close. The place to stop the food frmo getting in is your mouth and if you can't control that your screwed.

[mooeypoo]

Pinch: Makes sense.. Though, it shoudl be happening also in the morning ('till you finish digesting last day's lunch or soemthing) .. I think O.O

 

Neuro: what you say sounds really logical but I could also say the same about the breathing system, which actually CAN be shut close....

 

And you just gave me an idea ---

 

Do eating disorders have anything to do with a physiological problem with the STOPPING to eat? It might be more than just psychological?

 

~moo

[Neurocomp2003]

There is also the thing that your physiological system is also controed partly by your brain...so its hard to define physio vs psycho

[mooeypoo]

Yeah. The main question that makes me really wonder is whether eating disorders are strictly psychological or have also a physiological part...

 

I guess its also the main difference between "mainstream" medicine and homeopathy .. or.. err.. i think.

 

anyways thanks for your answers

 

~moo

[qazibasit]

actually when you have had big meal then there is unusual increased peristalsis (movement in stomach and intestine) this activity is so high that it stimulates the local enteric nervous system of GIT which cause the internal sphincters to open causing a desire to deficate(evacuate) and hence all the rectal contents the previous ones (digested ) and the current ones that reaches the jujenum and ilium (without the nutritional absorbtion) are ejected.

[admiral_ju00]

Eating disorders are almost always psychological.

 

{edit}

 

damnit, i hate the revival of old threads. should have paid att to the date this b'4 posting. grrrrr

[mooeypoo]

hehe well it's okay, you managed to revive me in the process ;p

 

I agree that the eating disorders are psychological, but thats not what I've asked. The "full" feeling we tend to have after eating much - is that a psychological "i shouldn't eat more" or is that a PHYSIOLOGICAL "shouldn't eat or you'll feel bad" mechanism?

 

~moo

[Glider]

Arguably, any 'feeling' is psychological. The hypothalamus is responsible for the basic behaviours; 'the three Fs' as they're known: Feeding, Fighting and Reproduction. Destruction of certain areas in the hypothalamus of rats results in uncontrolled feeding (gluttony). These areas respond to input from stretch receptors in the stomach, which signal the current state of the stomach, empty, full or whatever in between, and also when physical capacity has been reached. These areas also respond to input from chemoreceptors which signal glucose levels in the body. Low levels trigger feeling of hunger, higher levels suppress apetite (usually).

 

Whilst the triggers and actions of these receptors and hypothalamic nuclei are physiological, their activity results in changes in psychological state. An empty stomach, or low blood glucose results in a psychological state involving feelings of hunger, preoccupation with possible sources of food and a strong psychological motivation to search for it.

 

There was an experiment in which hungry people and people who had recently eaten were shown large posters which contained a number of images related to food which were distributed among lots of distractor images (neutral things like trees, spanners, lamps etc.). The people were instructed to find the images relating to food as fast as they could. The hungry people located all the images significantly faster than those who had recenty eaten.

 

Subsequent research shows that we are a lot more sensitive to food related stimuli when we are hungry; colours, scents and anything else that relates to the possibility of food all become more pronounced and noticable to a hungry person than to a sated person.

 

In sated people, these states are suppressed. This is partly due to the actions of the hypothalamus which supresses the feeding behaviour and associated psychological drives, and partly due to blood being diverted from the periphery to the gut to aid digestion. The latter is responsible for the feelings of drowsiness and lethargy people often experience after eating.