OCR Text |
Show Structure & Function of the Esophagus in the American Alligator J. l>i?JEVT C Gamier. L)tL|> ultimo n=' I lining \. nfversify of I'tnh Mimrv+ K Cla i1 hUI+ ViiLTit Jj * . \ iJ i • i i i m I r :i f i u i L H »* |l tlal, S j \l I.il kt <n fl y phy^ioL^y of the gastrointjestinal system is increasing. In contrast to most itianunals, that generally eat relatively small meals at frequent intervals, many carnivorous reptiles consume exbvmely lai^e meals inftieq^iendy, Thus, the regulatory responses to feeding can be very pronounced in i^eptiles compared to mammals. Furtliermoi*h reptiles do not provoke the same level of controveisy surrounding animal research that mammals do. Recent research on the i^ptilian gastrointestinal system lias focused on responses to feeding that occur in the lower gastrointestinal tract. Relatively little recant work has examined tha upper GI tract. For thesa naasoni. wa undertook a study of esophageal structure and function in the American alligator. Five juvenile American alligators, (Alligator rnissJssippiensis) weighing 0.431 + 0.09 kg (S.E.M) were studied. Pressure was measured at 22 C along the esophagus. Peristaltic wavas had a speed of 206.815 + 4.1 (S.E.M) (by the aquation v = d/t). Furthaimona, we found a high-pressure zone of the esophagus located ceplialad to tiie stomach which indicated the presence of a lower esophaged sphincter. Histology einalyge£ of the longitudinal sectiom of the esopJiagus revealed the presence of cilia, siniilaj1 to that of the respiratory of mainmaL*, Thej^ wfi& Jio Btiiated muscle presenL t*rt we did see the expected rmjBculaj'is muoosa, a niyenteiic newe plexus, jnuais secreting goblet cells, a cuboidal epithelial la>rer and evidence of fin enteric nejvom ByBtejn. 31 |