[MUSIC] Okay, so lets look at the neuroanatomy of the control of voiding. The, the boss in this situation is the pontine micturition center. Micturition is a medical term for, urination. Same thing. But, physicians would call micturition instead of urination. So this is the pontine micturition center, and. Voiding depends on signals that come from the pontine micturition center, from the pons, down to the sacral cord where these parasympathetic neurons are that innervate the, the bladder muscle. And also, also the, the voluntary motor neurons are. That innervate the external urethral sphincter. So that means that, the sacral cord is sitting very vulnerable, very long way away, and any damage in this entire zone of the spinal cord has the potential. So leave these sacral cord neurons on their own. So spinal cord damage anywhere between the start of the spinal cord and mid sacral levels has the potential to prevent, any voluntary voiding. Now, contrast that with breathing which is, depends on motor neurons in c3-c4. And so you can see that breathing there's a much smaller area of the spinal cord. Where you're going to get damage that's going to affect breathing, then the area of the spinal cord where you can get damage that affects the ability to void. So, what happens when the sacral cord is left on its own? Let's say we had a, a spinal cord injury that cut the cord. Well, in this situation, what happens is that these. These movements become reflexive. They're left on their own, they become reflexive. And the bladder contracts every, excuse me, every time the volume increases. The bladder contracts. But the external urinary sphincter is a voluntary muscle. And so it will not relax. And so this is contracting and this is tight. It's very tight. Nothing's happening. And this dyssynergia or this discoordination between the two muscles is probably the most common initial complication of spinal cord injury that has to be taken care of right away and there are no treatments that solve this, and basically this is typically solved by cathe, catheterizing the person. And I should mention that not everyone with spinal cord injury has this because some people have an incomplete spinal cord injury that doesn't actually cut the pathway from the pons down to the sacral cord. Now I said before hand that, it took even more than just the, the movements of these two muscles to, to for us and for dogs and cats to void and the signal that it's okay to void comes from the prefrontal cortex. From the cerebral cortex and it's an area in here that says okay,. This is a safe area. This is a, an appropriate time and place in which to void, and the, then engages the pontine micturition center. And what's, what's very interesting is that strokes in this area, which do happen, Not extremely commonly but they do happen, can leave this system intact but incorrectly triggered so people will void in inappropriate places or times and in some situations they will be actually, they won't care that they have voided, they have no. They have no social embarrassment about it. other, other, other strokes in this legion will lead to enuresis which means voiding at night time. So, serve a pattern that goes back to babyhood. But will have intact voiding during the day. So there are places all along here where avoiding is controlled and it'll produce very different types of effects. From the, the very disturbing, these are, these are not happy. Symptoms for people to, to deal with or for the loved ones of, of the afflicted to deal with. To just simply, got to take care of it, because it's not going to work. These spinal cord injuries. Okay. So that is what, what we're going to cover with respect to voiding and now we're going to move on. To the final segment on sleep and wake. [MUSIC]
