Visceral receptors and their afferents in the caudal mesenteric nerve of the duck.
1. The behaviour and reactivities of visceral receptors to different mechanical and chemical stimuli in simple unit preparations from the caudal mesenteric nerve of adult ducks were studied to examine the physiological roles of such receptors. 2. In total, 83 single unit activities were recorded from the caudal mesenteric nerve. 3. Receptors were grouped according to their locations in different layers of the rectum as (i) over the branching points of the blood vessel or in the serosal layer, (ii) in the muscle layer or (iii) in the mucous membrane of the rectum. 4. All the receptors, both spontaneous and non-spontaneous, responded to mechanical probing. Receptors of the muscle layer responded to distension also and showed a slowly-adapting nature. Most of the receptors of the other two groups were of the rapidly-adapting type. 5. Conduction velocity ranged from 0.76 to 34.6 m/s. 6. Sympathetic afferent fibres from the hind gut ascend along the intestinal nerve and join the caudal mesenteric nerve via the colonic ganglion.
D000818:Animals; D004372:Ducks / Q000033:anatomy & histology*; D007413:Intestinal Mucosa / Q000294:innervation; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology; D008643:Mesentery / Q000294:innervation*; D009475:Neurons, Afferent / Q000502:physiology; D012007:Rectum / Q000294:innervation*; D011984:Sensory Receptor Cells / Q000502:physiology*