Or, hiatal hernia anatomy.
In a hiatus hernia the gap in the diaphragm that the oesophagus passes through also allows the stomach (and maybe more) to pass from the abdomen into the thorax. Let's look at the anatomy here, including the lower oesophageal sphincter, the phrenoesophageal membrane, have a think about the pressure differences in the thorax and abdomen, the types of hiatus hernia and possible effects.
Music by Jahzzar
Album: HiFi City Tales
Song: Bodies
https://soundcloud.com/jahzzar
