Colonic Motility in the Cat

Abstract

Abstract R ostad Colonic motility in the cat. 11. Extrinsic nervous control. Acta physiol. scand. 1973. 89. 91–103. Experiments were performed on cats lightly anesthetized with pentobarbital sodium and a neuromuscular blocking agent, pancuronium bromide, in order to study the distribution of the extrinsic colonic nerves and their influence on the motility of various parts of the colon. The motility was recorded in its proximal, middle and distal part with sensitive extraluminal strain gage transducers and arterial blood pressure and respiratory movements were recorded using pressure transducers. The influence of the extrinsic nerves on the colonic motility was investigated both by sectioning of the nerves and by electrical stimulation of the peripheral ends of the cut nerves. There was no marked functional differences between the proximal and distal portions of the colon. The vagal and splanchnic nerves, containing pure motor and inhibitory fibres, respectively, have their functional distribution throughout the greater part of the colon, although most marked in the proximal part. The parasympathetic pelvic, nerves supply the whole colon with motor fibres. At just suprathreshold stimulation of these nerves the responses in the proximal part of the colon were of lower amplitude and longer latency than in the remaining portions. The sympathetic lumbar colonic nerves distribute to all parts of the colon with mainly inhibitory fibres, but have some excitatory fibres as well.