 Dr. Sanjay Sanyal, Professor Department Chair. This is going to be a demonstration of the platter. So this is supine cadaver. I'm on the right side. Camera person is on the left side. We have completely dissected all the structures in the pelvis and this structure that we see in front of us This is the urinary platter. This is the apex of the platter and we can see this ligament arising from the apex This is the median umbilical ligament, which is the remnant of the urex which is derived from the alan toy and this goes and gets attached to the umbilicus on the inner surface of the anti-abdominal wall. We see these two ligaments on either side. These are the medial umbilical ligaments which are the obliterated distal portions of the umbilical artery, which is a branch from the anterior division of the internal iliac. This also goes to the umbilicus. In life, these structures are located on the inner surface of the anti-abdominal wall and there's a depression on either side of the median umbilical ligament here and here. These are called the supravisnical fossa, which can be a potential site of herniation. To continue, we have opened out the space between the bladder and the pubic symphysis. This is known as the pre-vecycle space. This is filled with endopelvic fascia. This space is also referred to as the cave of redsias. In life, this is filled with vesicle venous plexus, which becomes continuous with the prostitic venous plexus. Normally the bladder is below the level of the pubic bone, intra-pelvic organ, but when the bladder gets distended and for some reason we cannot pass a catheter through the urinary passage, we have to do what is known as a suprapubic systostomy and we do the suprapubic systostomy through this root, where my instrument is pointing. To continue with the parts of the bladder, this surface of the bladder was covered by peritoneum and this is the dome of the bladder. And this peritoneum, which we have removed, continues and gets reflected onto the rectum, which is this structure here. The place where the peritoneum gets reflected from the bladder to the rectum. That is known as the recto-vecycle pouch. In females, uterus is lying on the dome of the bladder, so therefore there will be a vesicle uterine pouch. Any portion after that is extra peritoneum and we will come to that in a little while. We will pick up the bladder to show you this portion now. This portion is known as the fundus. It is extra peritoneum. The fundus of the bladder is also called the base of the bladder because it is opposite the apex. It is also the posterior surface of the bladder. This is the structure, which is in relation to the rectum, separated by the recto-vecycle septum. And it contains three structures in the male. And we can see the two structures here. One of them is the ductus difference, which is going inside. And then we have the ureter, which is also going. And there will be a structure which is not visible, but further lower down. And that will be the seminal vesicle. So these are the three structures which are separating the posterior surface or the base of the bladder from the rectum and the recto-vecycle septum. And to show it more clearly, I will lift up the bladder and we can see. This is the ductus difference here on this side and the ductus difference on this side. And we can see the ductus difference here becomes a little dilated. This is known as the ampule of the ductus difference, which will then unite with the duct from the seminal gland and form the common ejaculatory duct, which will go through the prostate and open as the common ejaculatory duct into the prostate ureter. This is a post-operative case. So therefore, this whole area was highly fibrous. But we can see a few of the blood vessels which are coming to the bladder from the proximal portion of the umbilical artery. And these are the superior vesicle arteries on this side. And these are some remnants of the superior vesicle artery on this side. They are the ones which supply the dome of the bladder. The ductus difference gets supplied by branch from the inferior vesicle artery. And these are known as differential arteries. The inferior vesicle artery is also a branch from the anterior division of the internal iliac. Now let's take a look at the interior of the bladder. And for that, we have sliced open the bladder on its anterior surface. And I have tilted the bladder back and we have opened the bladder. This is the interior of the bladder. We can see first of all the bladder mucosa. It is thrown into slight folds. After that, this is the thickness of the bladder wall. This contains a smooth muscle which is referred to as the detrusor muscle. This detrusor muscle is under parasympathetic control. Parasympathetic causes contraction and sympathetic causes relaxation of the bladder. And if we look very closely here, we can see a triangular shaped structure here. This is the trigone of the bladder. This trigone is located in the floor of the bladder. What are the components of this trigone? We can see this structure, which I have lifted up here. And when I pull, we can see it is exerting traction on the ureter on this side. Similarly, when I pull here, we can see it is exerting traction on the ureter on this side. So these are the openings of the two ureters. The ureters, when they enter the bladder, they enter in a beveled fashion. The purpose being to prevent vesico uretric reflux in normal circumstances. Therefore, it acts as a valvular mechanism. When this valvular mechanism fails, then we get what I mentioned as the vesico uretric reflux. For the same reason, this ureter vesicle junction is also a potential site of uretric constriction, where a small stone more than 0.5 centimeters can get impacted. In which case, there will be hydrouritor and hydronephrosis. This is an axial CT scan at the level of the hip joint to show a right UVJ calculus and right hydrouritor. If we look further closely, we will see a ridge joining the two openings of the ureters. This is referred to as the interuritric bar. Lower down, we can see yet another opening here. That is the opening of the urethra. That is the internal urethral meatus, which is also encircled by a smooth muscle, which is the internal urethral sphincter. This is relaxed by this parasympathetic and contracted by the sympathetic. So therefore, parasympathetic is for a mixturation purpose. This trigone of the bladder is derived separately from the rest of the bladder. The bladder is derived from the endoderm of the urogenital sinus, while the trigone is derived from the misodermal wolfian duct. Mucosa of this trigone is very sensitive. When we are doing a uroscopy examination of the bladder and we reach the internal urethral meatus, at that position we cannot see normally the two openings of the ureter. However, when we advance the uroscope even further, then we can see these two openings. That is the normal situation. However, when the patient has got benign hypertrophy of the prostate, then the internal urethral orifice is pushed up by means of the median lobe of the prostate and that is referred to as the uvula of the bladder, and in which case we get a condition known as marioncine positive. What is this marioncine positive? It means that in the same cysto uroscopic view, we can see all the three orifices hemogenously. So, when a patient has got enlarged prostate, the median lobe is enlarged, there is a depression behind the median lobe of the prostate and that is known as the post-prostatic pouch. Whenever the patient lies down, there is irritation of the post-prostatic pouch, the trigone of the bladder by means of residual urine and that is what produces nocturia and frequency in a patient with benign hypertrophy of the prostate. I have again come to the posterior surface or the base of the bladder to show the unique relationship of the ductus difference and the ureter. So, I have pulled it up to show you the normal relationship and we can see that the ureters are crossed over by the ductus difference on either side. This is because during embryonic life, the testis descends down and the kidneys ascend up and so therefore, this is the place where the ductus difference crosses the ureter. This can rarely be a site of constriction of the ureter where again a stone can get impacted. So, these are the points that I wanted to mention to you about the bladder and the related structures in the pelvis. Thank you very much for watching Dr. Sanjay Sanyam signing out. Mr. Kendall Cumberbatch is the camera person. If you have any questions or comments, please put them in the comment section below. Have a nice day.