Hello everyone,

 

 

From this pic it looks like air can go to oesophagus if you breathe from nose, but this is not happening. Is their some sphincter for this, or what? Thanks

When you breath in through your nose or mouth the air is traveling to a region of lower pressure. Pressure is lowered in the lungs by movements of the ribs and diaphragm. In my experience most little 6 to 8 year old boys learn how to lower the pressure in their stomach in order to inhale gas for making rude burbs, especially when their parents are having a visit from their adult friends or relatives. SM

The digestive tract has several sphincters, including the upper esophageal sphincter, which helps prevent air from being drawn into stomach (except for 6 to 8 year old boys ^—Brruuup!! ).

Surely the action of the lungs expanding draws air into them whereas the stomach doesn't alter in size in the same way? The stomach does not provide a partial vacuum to suck in air. (imo)The sphincters asociated with the oesophagus are probably there mainly to allow food in and prevent it coming back out.

A LOT AIR CAN BE SWALLOWED DURING EATING HURRIEDLY AND PASSED OUT IN THE FORM OF BURPS AND GAS (FLATUS)

A LOT AIR CAN BE SWALLOWED DURING EATING HURRIEDLY AND PASSED OUT IN THE FORM OF BURPS AND GAS (FLATUS)

 

Yes it gets pushed down with the food as you gulp. You can, if you so wish, gulp air into the stomach without eating but (imo) its not a very natural thing to do. Normally I would not expect air to be travelling through the nose unless the lungs were expanding and contracting. If the top sphincter is not a perfect seal I can imagine a small amount of air being sucked OUT of the oesophagus as you breath IN and a similar small amount of exhaled breath being forced INTO it when you breath OUT. I wonder if this is how some tabacco smokers develop stomach cancer.

Thanks everyone I totally forgot about the pressure difference.

I think that the sphincters that keep food from flowing out of the stomach will also prevent air from flowing in. And there isn't really a low pressure zone in the stomach to draw air in -- if you want something to go into your stomach you have to push it in by swallowing.