Autonomic Nervous System of the Pelvis

00:01 Now, let's return to the GI tract and have a look at the rectum and the angel canal and it's autonomic innovation.

00:10 So here, we can now start, bringing together a lot of the autonomic nerves that we've spoken about within the pelvis together.

00:17 We've mentioned things like superior hypogastric plexus.

00:21 This is a communication with the inferior mesenteric plexus that went and helped it supply the hindgut.

00:28 We can see lumbar splanchnic nerves are contributing to it.

00:31 But here we see coming away from the superior hypogastric plexus is that hypogastric nerve.

00:38 We can see it here on the left hand side.

00:40 And that's going to form the inferior hypogastric plexus.

00:43 We can see here.

00:45 We do also have continuation of sympathetic trunk all the way down into the pelvis alongside the sacrum.

00:52 We can see here.

00:53 And that also helps to give rise to sacral splanchnic nerves that are sympathetic in nature passing towards the inferior hypogastric plexus.

01:02 But remember, these aren't coming from the sacral spinal cord.

01:06 They're coming from the sacral aspect of the sympathetic chain.

01:10 They've come from T1 to L3, passed as preganglionic fibers to the sympathetic chain and then descended all the way down via the synthetic chain to the sacrum.

01:22 Then they've decided to leave and help contribute to the inferior hypogastric plexus.

01:27 Delivering sympathetic fibers to the pelvic organs.

01:31 We can also see now we have nerves coming out of the sacral plexus so the spinal nerves and they're giving rise to these pelvic splanchnic nerves that are parasympathetic in nature.

01:42 Remember the parasympathetic nerves leave the spinal cord S2 - S4 which we can see here.

01:48 And they're now also contributing to the inferior hypogastric Plexus.

01:53 So you can now hopefully appreciate how the inferior hypogastric plexus is formed via the sacral splanchnic nerves, sympathetic.

02:02 Pelvic splanchnic nerves, parasympathetic.

02:05 And also has a contribution via the superior hypogastric plexus via the hypogastric nerves.

02:11 But we now have why the inferior hypogastric plexus and autonomic hub within the pelvis and that's important as we look to see how its innovated.

02:22 The inferior hypogastric plexus is going to give rise to nerve plexuses that supply the organs in the pelvis.

02:29 So the rectum, the uterus, vagina, the prostate, and the bladder.

02:34 All of these will have their own autonomic nerve plexus, Coming from the inferior hypogastric plexus formed from the sacral sympathetic, pelvic parasympathetic, splanchnic nerves.