The esophagus is more than just a "food tube."  It is a complex muscle that propels food from the mouth into the stomach.  Reflex muscle movements move in a coordinated fashion to push food through the esophagus.  This is why you can swallow while standing on your head (although this is not recommended!).  Food moves from the back of the mouth into the top of esophagus quickly as the swallowing process begins.  This accomplished by backward movement of the tongue and muscle movements in the back of the throat.  Breathing is temporarily stopped as the epiglottis closes the opening to the trachea.  The epiglottis looks somewhat like a toilet seat cover, however in this instance the toilet moves upward and under the lid cover, instead of the lid dropping over the toilet!  Food slides over the epiglottis into the esophagus. The esophagus is about 25cm long in young child and has an upper and lower sphincter (a muscular band valve that opens and closes).  A wave of muscular contraction (peristalsis) pushes food into the stomach.  These waves travel at a speed of 2-4cm per second, and the total travel time of food in the esophagus is about 9 seconds or less.