Cineradiography of the reticular groove mechanism.

The use of cineradiographic studies in the interpretation of how sucked liquid passes to the abomasum in young sucking ruminants is described with special reference to experimental studies in lambs and calves. The work involved an examination of the movements of stainless steel wire or clips inserted via a gastrostomy into the mucosa of the caudal thoracic oesophagus, lips of the reticular groove and margins of the reticulo-omasal orifice. This assisted the interpretation of how these structures are involved in the passage into the abomasum of sucked liquid and into the reticulo-rumen of liquid or solid ingesta or saliva swallowed independently of sucking. An understanding of contributions made by the oesophagus, reticular groove and reticulo-omasal orifice to the passage of sucked liquid into the abomasum was aided by the use of the autonomic blocking agents, atropine and hexamethonium.