D.  ESOPHAGUS ANSWERS:

     1.  NOTE --- root PHAG means to   E A T   as in the words MacroPHAGe
            or   PHAGocytosis

     2.  P E R I S T A L S I S   moves food to the stomach

     3.  A ring of circular muscle called a  S P H I N C T E R  controls the flow
          of food into the stomach

Cardiac  S P H I N C T E R  between esophagus and stomach.   ...
       This circular valve has nothing at all to do with the human  H E A R T. 
It just happens to be near-bye.