Search Result for "physiological sphincter":
Wordnet 3.0

NOUN (1)

1. a sphincter that is not recognizable at autopsy because its resting arrangement cannot be distinguished from adjacent tissue; 



WordNet (r) 3.0 (2006):

physiological sphincter
    n 1: a sphincter that is not recognizable at autopsy because its
         resting arrangement cannot be distinguished from adjacent
         tissue