Topographic photograph in newborn guinea pig shows (A): The esophagus(E), stomach(S), small Intestine(Si),large Intestine(Li), esophagus cervical section (Ce), esophagus thoracic section (Th), esophagus abdominal section (Ab), esophageal hiatus (H), diaphragm (D), esophageal sphincter muscle (Sm). (B1_PS): stomach parietal surface: gastroesophageal junction (Gj), pyloric antrum (Pa), lesser curvature (Lc), greater curvature (Gc). (B2_VS): stomach visceral surface: stomach cardiac region (Ca), stomach fundic region (Fu), stomach pyloric region (Py), esophagus sphincter muscle (Es), cardiac opening (Co), pyloric opening (Po), rugae (R).