always remains patent (open). source; http://en.wikipedia.org/wiki/Nasopharynx source: http://helmizakariah.blogspot.com/2008_03_01_archive.html The esophagus (or oesophagus ; see spelling differences ), sometimes known as the gullet , is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach . During swallowing food passes from the