Why can you not breathe when you swallow?

Breathing – you are not able to breathe when you swallow because your respiratory (breathing) system is closely linked to your alimentary (nourishing) system. In fact, both the air you breathe and the food you eat travel down the pharynx, a wide muscular tube situated behind the nose and mouth. The air must reach the larynx or voice box on its way to the trachea (principal air passage) and the lungs, while the food has to go by way of the oesophagus (gullet) and stomach. Obviously some kind of device must be used to prevent the two from becoming mixed up. Swallowing temporarily interrupts breathing by closing the air passages while food is propelled from the mouth to the gullet and stomach. If a particle of food goes the wrong way the lungs respond immediately by trying to expel the food with a cough. Also some air does find its way to the stomach and can if excessive cause flatulence or “wind”.