[Origin of the secondary peristalsis of the esophagus in sheep]

Manometric and electromyographic methods were used for investigating oesophageal motor activity in conscious sheep. A contraction wave, the so-called "secondary peristalsis", was readily evoked by means of the fast inflation of a rubber balloon distending the oesophagus. This peristaltic wave travels onto the cardia at the same speed as the primary deglutitive peristalsis (28 m X sec-1, approximately). In that particular species, whose oesophageal muscular coat is all along entirely made of striated fibers, secondary peristalsis is always initiated at the origin of the cervical oesophagus, whatever the site, cervical or thoracic, of the distension.