Search

The conservative or nonsurgical treatment of voiding dysfunction has improved significantly, due predominantly to an improved understanding of the basic neurophysiologic mechanisms regulating the function of the bladder and urethra. Although still far from satisfactory, further research will undoubtedly open new avenues of treatment.

The circulation of blood through the colon has received little attention as compared to that of skeletal muscle or even the small intestine. One obvious reason for this neglect is the relative inaccessibility of the organ, even though qualitative information has been gained from studies of human colostomies. Our ignorance is reflected in the fact that not until a few years ago was any quantitative information available concerning blood flow in the human colon. This review attempts to summarize our knowledge in this field, but in some instances analogous conclusions from observation made on the small intestine have been made, due to the scarcity of data pertaining to the large bowel. Furthermore, the review is almost exclusively based on observations made on carnivorous animals, where the cecum is small or absent.

Dense networks of enkephalin containing nerve terminals have been identified in mammalian sympathetic and parasympathetic ganglia (1, 12, 20–22, 25, 35). Evidence from various sources indicates that enkephalins are contained in, and released by axons that arise from neurons extrinsic to the ganglia, and that enkephalins have an inhibitory effect on ganglionic transmission (2, 12, 23, 25, 26, 30, 36, 39).