Electrical Activity of Gastrointestinal Smooth Muscle. The GI smooth muscle acts as a functional syncytium. Characteristic features of the basic electrical activity of GIT & its relation to smooth muscle contractile activity under physiologic conditions.
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Characteristic features of the basic electrical activity of GIT & its relation to smooth muscle contractile activity under physiologic conditions
Each time the peaks of the slow waves temporarily become more positive than -40 millivolts, spike potentials appear on these peaks
The higher the slow wave potential rises, the greater the frequency of the spike potentials, usually ranging between 1 and 10 spikes per second.
Figure 62-3; Guyton & Hall
Important factors that make the membrane potential more negative—hyperpolarize the membrane and make the muscle fibers less excitable—
- postganglionic - short, entirely in ENS
Synapse with ENS neurons (mainly)
Reflexes from the gut to the spinal cord or brain stem and then back to the gastrointestinal tract