Motor and Sensory Function

Studies of small intestinal motor and colonic motor activity in man have been limited by the relative inaccessibility of both organs and by issues related to the presence of stool in the colon. Nevertheless, considerable progress has been learned from animal and human tissues of the basic morphology and physiology of the small intestine and colon and the primary patterns of motor activity in both organs have been described in normal man. The role of the gut as a sensory organ is increasingly recognized and the various neural elements involved in conveying sensory information to the central nervous system as well as the areas in the brain activated by such input identified. In all of this, the importance of the intrinsic electrophysiological properties of gut smooth muscle cells, the primacy of interstitial cells of Cajal as pacemakers and the ability of the enteric nervous system to generate and coordinate much of the motor activity of the gut the regions have emerged as essential factors in gut motility and sensation.