Which factor is NOT involved in the control of intestinal motility?

The physical structure of the intestine does not directly influence the control of intestinal motility in the same way that hormonal and neural control mechanisms do. While the physical structure may play a role in the overall function and effectiveness of motility, the regulation of how the intestines move is primarily governed by complex interactions involving hormones and the nervous system.

Hormonal control involves various hormones like gastrin, secretin, and cholecystokinin that provide signals to regulate activities such as smooth muscle contraction and secretion of intestinal juices, thus affecting motility. Neural control is fundamental through both the central and enteric nervous systems, where signals are sent to coordinate contractions of the intestinal muscles for effective peristalsis and segmentation.

The consistency of chyme likewise affects motility but is more of a consequence of digestive processes rather than a mechanism for controlling motility itself. For instance, thicker chyme might slow down movement while more fluid chyme may increase speed, but this is not a direct control factor. Thus, the physical structure, although relevant to the efficiency of motility, isn't a regulatory mechanism in the way hormone and nerve action is.