Understanding the Perineum and Its Structures

Okay, the topic that we're going to start here is the perineum. It's another very, very important topic and you can certainly expect a lot of questions from the perineum part. And you know, the reason we find this topic bit, you know, bothering to most of us because the orientation in the perineum is like... It's not very good for most of the people. I mean we are not very much oriented to how exactly the structures are located, where we have the urogenital triangle, how is the anal triangle formed, how these triangles are connected to each other, is there any connection between the ischial rectal force of both sides. So in the perineum part, the important thing is the orientation. And we first will start with the boundaries of the perineum. If I say, okay, you read the perineum by yourself, you probably will not pay much attention to the boundaries. You will say, okay, pouches are very important. Let's talk about the deep pouches and superficial pouches. But remember one thing, until unless you know the exact boundaries of the perineum, you will always find it difficult to understand all the perineal pouches or be it anal triangle. So let's start with this picture where you're looking at the pelvic bone from the inferior aspect. So this basically is a lithotomy view. So guys look at this structure starting from here this is obviously is what that is pubic symphysis. We got the pubic bone that is a pubic bone. This ramus here that is a ischio-pubic ramus. This is ischio-pubic ramus. This tuberosity that is ischial tuberosity here and stretching from ischial tuberosity to the sacrum that ligament that is what sacro-tuberous ligament. I repeat again that is a pubic symphysis that is pubic bone. The ramus is what ischio-pubic ramus. We got this ischial tuberosity and stretching from the ischial tuberosity till the sacrum, the ligament is sacro-tuberous ligament. Now this is the boundary of the perineum in which we have everything, all this pelvic diaphragm, urogenital diaphragm and triangle, all we need to discuss inside. The second important thing about perineum is how we divide the perineum. Now look at my hand where I am putting it guys. If I put my hand like this. That means if a line is passing from the anterior margin of ischial tuberosity here, now that will divide the perineum in two triangles. The small triangle which is present in front, that is called as the urogenital triangle because all the urinary structures and the genital structures will be seen there. You will see the opening of the urethra, you will see opening of the vagina, the bulb of the penis, the crust of the penis, all are located in that region, so we call it urogenital triangle. Whereas this triangle behind, which is behind this level of ischial tuberosity, this is called as anal triangle. And all we have inside anal triangle is the anal canal. And both the side of anal canal you will see ischio-rectal or so called ischio-anal fossa. So that is what we are going to start with. We will start with the boundaries and we will bend up in the perineum. Before we start with this topic and go into detail of that, also remember one thing. When you start reading perineum in any of the textbooks, they have explained perineum starting from the skin and going upwards. Like they first will talk about the skin, then the superficial fascia, the colis fascia and so on. And yeah, this is how it should be. I mean, we have to dissect from inferior to superior only and that's how it is explained. But I very, very strongly feel that if you understand the perineum from superior to inferior, it is much better view, you have a better orientation of the perineum. Like, if you start from pelvic diaphragm, which is the highest layer in the perineum, or you can say it is the superior most structure in the perineum, and you keep on looking what is below that pelvic diaphragm and then below, till we reach the skin and the fascia. So that is how we are going to approach. We will start with the pelvic diaphragm, that is the first layer, and then we will come to the triangle below that is urogenital triangle and all those things. Third important thing about perineum apart from this boundary and how we'll approach it is that when you talk about perineum it is in the lithotomy. So that means you are seeing it from the inferior aspect. Now when you see it from the inferior aspect, everything that you find first, that is superficial, is actually inferior. We have to start dissecting from inferior to superior. So skin, then fascia, then that means we are going deeper. The more we go above, the more we go up, that means we are going deep. So every time I use the word superficial in the perineum, that means it has to be below. It has superficial, superficial means it is down. But when I say deep, deep layer of urogenital diaphragm, deep perineal pouch, then we are talking about something which is above, right? So superficial is below and deep is above in the perineum because the approach is from inferior to superior only. So keeping these general things in mind, the boundaries of the perineum, how we'll approach it, that is we'll approach it from superior to inferior and everything in the inferior, everything which is inferior in the perineum is what? Superficial and deep is above. Let's start with this topic. Okay, so I'll... As already we discussed the boundaries of the perineum, so if I just quickly go through it once again, that was the pubic symphysis. Here is the pubic bone. This is ischio-pubic rami, ischio-pubic ramus. This is the ischial tuberosity, sacro-tuberous ligament, and of course that is the sacrum and coccygeal vertebrae. And the important point is we said if you draw a line, imaginary line from the anterior margin of the ischial tuberosity that is dividing the perineum in these two important triangles. This is the urogenital triangle that you see in front having all the urinary and the genital structure that is urogenital triangle. And the triangle behind this is having anal canal and on either side we have ischioanal fossa. So that is called as the anal triangle. Our topic here is the perineal pouches. So we will be focusing on the urogenital triangle. So as we said, let us start with the highest layer in the perineum and then we will keep on building it downwards. So what was the highest layer? The highest layer is the pelvic diaphragm. So that is what we are going to start with. pelvic diaphragm. So I'm just going to draw the schema of what we just saw. So the boundaries are somewhat like we have this pubic symphysis and ischio-pubic ramus. Then we got this sacrum and coccygeal vertebrae present here and that is the sacro-tuberous ligament. Just drawing the boundary of the perineum. This is the East chill tuberosity. Now what is Pelvic Diaphragm? Pelvic Diaphragm is a combination of three muscles coming from three different parts of hip bone and all of them are converging to the coccygeal vertebrae. Now this here is the coccyx, this is the coccygeal vertebrae and you will see the muscles coming from three different parts and all of them are converging here. Like there is a muscle coming from the pubic bone that is called as pubococcygeus. There is a muscle coming from the ileum. or mainly from the obturator fascia that is called as iliococcygeus and similarly we have this ischio coccygeus now these are three muscles together which are called as pelvic diaphragm this is the pubococcygeus this here is iliococcygeus and then we got the ischio coccyges, ischio coccyges is simply called as coccyges also either you call it ischio coccyges or just coccyges all these three muscles together are called as what? pelvic diaphragm so pelvic diaphragm is basically the combination of these three muscles the pubo, ilio and ischio coccyges and you must have seen that pelvic diaphragm and levator anion These are the two words which are used interchangeably sometimes. But there is a slight difference guys. When you say pelvic diaphragm, you are counting all the three muscles. But when you say levator ani, then you are talking about only pubococcygeus and iliococcygeus but not ischiococcygeus. Ischiococcygeus in human, it's a kind of vestigial muscle only. Because ischiococcygeus in certain lower animals, I mean it is for the movement of the tail. So in human it is not having any functional importance. So, it is the pubococcygeus muscle and the iliococcygeus muscle which together are referred as what levator anion. These are the two muscles which are together called as levator anion. Just remember this difference here first that pelvic diaphragm is like all the three muscles together but levator and eye is just pubococcygeus and ileococcygeus. Now let us imagine this as a section of the female perineum. Now if this is a section of female perineum we will expect to have three major openings in the pelvic diaphragm one for the urethra for the vagina and for the rectum. So we got these three major opening that is for the the urethra, vagina and the rectum. And see what is the muscle which is closest to all the three openings. The muscle out of the three in the pelvic diaphragm which is closest is what? Pubic Oxygen. Therefore you will see the pubic oxygen muscle is forming the sling around all these openings. So these muscles which are acting as a functional sphincters around these major openings are basically extension of pubic oxygen. So that is one question here that what? are the modifications of pubococcyges. So, one you see it around the urethra, one you see around the vagina and the one that you see here is around the rectum. So, this is called as pubourethralis, that is pubourethralis. We got puboviginalis and this is the pupil Pupourethralis covering the urethra you can see, pubovaginalis around the vagina and the puborectalis which is maintaining that anorectal angle that is puborectalis all these three muscles are the modifications of all of them are the modification of which muscle? They are all modification of pubo. That is one important point, one important question here that what muscles are the or what are the modifications or extensions of pubococcyges. And out of all these specially this one the puborectalis, it is very very important as we said puborectalis is the muscle which maintains that anorectal angle and it is also called as muscle of continence. The muscle of the rectal continence, the puborectalis it maintains the anorectal angle and called as muscle of So, this is the first thing guys that is we started with the highest layer that is pelvic diaphragm. What are three muscles forming pelvic diaphragm and the innermost muscle is forming all these modifications. Now, as we said we will start from the superior and we will keep on going downwards. So, let us go below the pelvic diaphragm and remember what we said below means what we are going superficial. So, going below means we are going superficial. Now when you go below the pelvic diaphragm, there is another diaphragm you will see. If I just once again sketch these boundaries roughly, right? These are the boundaries. So below the pelvic diaphragm, there is another diaphragm which is present in this triangle here. Now what is this triangle guys? This triangle was urogenital triangle, right? So if this is a urogenital triangle, obviously the diaphragm will also be called as urogenital diaphragm. So please remember that we have a pelvic diaphragm. There is a pelvic diaphragm first. You are seeing it from inferior aspect. There is a pelvic diaphragm first. And below pelvic diaphragm, now we have another diaphragm that is only in the urogenital triangle. And we call it what? Urogenital diaphragm. Please remember, urogenital diaphragm is a double layered structure. we have a superior layer of urogenital diaphragm and then we have inferior layer of urogenital diaphragm. And because we are saying you are seeing it from the inferior aspect, you are seeing it from the inferior aspect. So, you are looking at which layer? Is it superior or inferior? So, you are looking at what? Inferior layer of urogenital diaphragm. There will be one more above it that is superior layer exactly like this. But this here, please note is the inferior layer of urogenital diaphragm. This is inferior layer of I am writing UGD, urogenital diaphragm, inferior layer of urogenital diaphragm which is also called as perineal membrane. Do remember this name, we will be using it very frequently in this topic. Inferior layer of urogenital diaphragm which is also called as what? Perineal membrane. So how many layers till now guys? How many layers? Three. Starting from superior to inferior, that is pelvic diaphragm. Next, we have superior layer of urogenital diaphragm. And the one that you are looking at right now here is the inferior layer of urogenital diaphragm. So till now, we talked about three layers. Now let us say this is a section of the male perineum. So what you will see here, you will see the bulb of the penis and the crust of the penis with their respective muscles around them. Bulb of the penis, we have a muscle around the bulb of the penis, that is muscle on the bulb. it's not a bipineate muscle these are two muscle meeting at the midline rapid and you also will appreciate a muscle present on the cross they are below the urogenital diaphragm of course that's why I'm drawing here because it is below and I want you guys to think about see what is what should be the name of these muscles now this here is the bulb just writing bulb because in case of female it will be like bulb of vestibule so of penis or bulb of vestibule but what is the muscle around this bulb this muscle is not only covering the bulb of penis the muscle is going forward and also covering the spongy urethra so the muscle is what this is bulbospongiosis that's very very important to remember the name here that is bulbospongiosis the muscle on the bulb of penis that is bulbospongiosis Now this is the crust of the penis and the muscle on the crust of the penis is called as ischiocavernosis. The muscle will come from the ischium, look this is the ischium here and this muscle from the ischium will go and cover the cavernous portion of the penis which is filled with the blood in the erection. So that is ischiocavernosis. That is ischiocavernosis. So we have a muscle on the bulb called as bulbospongiosis and the muscle on the crest which is called as ischiocavernosis. There also is a muscle running transversely in the perineum. Now look at this muscle guys, it is present transversely in the perineum. Now first of all it is running transversely in the perineum, so we call it transverse perineal muscle. But this transverse perineal muscle is present below the urogenital diaphragm. So it is superficial or deep? We said everything, whatever is below is what? It is superficial. So this muscle is called a superficial transverse perineal muscle. So the muscle that you are looking at here, this is Superficial Transverse Perineal Muscle, that is a Superficial Transverse Perineal Muscle, that is Superficial Transverse Perineal Muscle. Whereas if you look at the anal triangle, although we are not discussing anal triangle in this section, but if this is anal triangle, we got an anal canal and we also got a muscle around it that is external anal sphincter. That is the external anal sphincter. the muscle around the inner canal that is external inner sphincter and this point where all these or this fibromuscular node where all these muscles are converging is a major major support for the pelvic viscera called as perineal body. So this is what you are looking at till now. We started with the pelvic diaphragm. If I just quickly go through this once again guys, the pelvic diaphragm. What was below pelvic diaphragm? Let's count all the layers individually. Below pelvic diaphragm, it was superior layer of urogenital diaphragm. Then we have inferior layer of urogenital diaphragm which is also called as perineal membrane. Below perineal membrane, you can see the bulb of the penis and crust of the penis which are covered with their respective muscles. Bulbospongiosis, ischiocavernosis. we also have superficial transverse perineal muscle and finally if below these muscles I will put a fascia that is colis fascia that will complete the layer of perineum for me so starting from pelvic diaphragm till the colis fascia this is all the superficial pouches and deep pouches the one we have to discuss are present between these layers only so we start with pelvic diaphragm and the inferior most we have this colis fascia but to reach the colis fascia where the colis fascia is and how it is seen there, we need to take an important section that is a sagittal section. It's a mid-sagittal section we have to take which will go through the bulb and the shaft of the penis here. Okay, so let's take a sagittal section. Let us take a sagittal section to understand this perineum well. So when you take a sagittal section, the highest layer is the pelvic diaphragm. So let's start from here. That is a pelvic diaphragm. That is a topmost layer. Let me write this PD for the pelvic diaphragm. Below pelvic diaphragm, we got this superior layer of urogenital diaphragm. And then even below that, we got this inferior layer of urogenital diaphragm. Like this. And what you see that superior layer and the inferior layer of urogenital diaphragm, they are both fusing anteriorly and posteriorly with each other. This is the superior layer, if I may write it here. This is superior layer of urogenital diaphragm and this is the inferior layer of urogenital diaphragm which is also called as what perineal membrane. So let me write that alternative name also that is perineal membrane. Because it is a mid-sigital section, so the section will go from the crust of the penis or the bulb of the penis. It will go from the bulb and the shaft of the penis. We are taking a sigital section, mid-sigital section. So guys, let us say this here is the bulb and the shaft of the penis. And there is the urethra which is running through. So that's the urethra which is running through. The bulb obviously will be covered with a muscle around. That is the bulbospondylus. I'm not drawing that muscle. And now coming to the last layer. See, we said that... starting from pelvic diaphragm we need to reach the lowest layer that is what? Colleus fascia. So what is colleus fascia and where it is? For that I again have to start from the anterior abdominal wall. I hope you remember that anterior abdominal wall is devoid of deep fascia and we have two layers of superficial fascia only on the anterior abdominal wall namely campers fascia and scarpus fascia. So guys let us say this is the scarpus fascia Now this scarpus fascia will continue in the scrotum as the dartos muscle and fascia and that will continue posteriorly as collis fascia. So it's a scarpus fascia only which you see will continue in the scrotum as the dartos muscle and fascia. And this datus muscle and the fascia which is forming a layer of a scrotum will continue towards the perineum as what? Collis fascia. So in a way they are all same. The scarpas will form the datus and that will continue behind as what? Collis fascia. And this collis fascia will Merge with the descending layer of perineal membrane. As you can see, I drew it like this, let me put an arrow. So, it's the perineal membrane which you will see fusing with the colis fascia and closing that space behind. So, one thing that you should be able to understand from this section, that there is a space present between the superior layer and inferior layer of urogenital diaphragm, that is one. And we also have a space which is present below the perineal membrane, or you can say below the urogenital diaphragm. And these are actually the two pouches. Try to write it where I am writing it. This is the deep perennial pouch. It is above, so it is deep. So we have a deep perennial pouch. And the one which is present below, that is superficial perennial pouch. The pouch above is deep perennial pouch. And the pouch below, that is superficial perennial pouch. We got to discuss the boundaries and everything about these pouches. But this is deep and superficial perennial pouch. Let me introduce you to one more terminology here. That superior layer and inferior layer of the urogenital diaphragm, when they are fused anteriorly, at this fusion we have a ligament and that ligament is called as transverse perineal ligament. This is called as a transverse perineal ligament. The transverse perineal ligament. So guys this is one very very important subject section which will give you a good orientation about that how the deep perennial pouch is formed and how superficial perennial pouch is formed. So I will talk about the contents of the superficial and deep perennial pouch in a while. Let us first talk about the boundaries. and the effect of the injury to the urethra in those particular pouches, in the deep pouch and the superficial pouch. So using this diagram, let us first talk about the deep perineal pouch. Now, even before we write, I want all of you to look at this. screen. Guys, deep panel pouch, roof is by what? It's clearly by superior layer of urogenital diaphragm, this one. Floor is by what? Floor is by the perineal membrane. Very clear. Posterior wall, same. The fusion of the superior layer and inferior layer, they are forming the posterior wall of the deep pouch. What is there in the anterior wall? That is transverse perineal ligament is in the anterior wall. So, it's very clear from this picture that the roof, floor, anterior wall, posterior wall is by what structures? But But what about the lateral wall? In the sagittal section, you cannot see the lateral wall. What should be the lateral wall of the deep perineal pouch and also for superficial perineal pouch? Think about it. See, what triangle are we talking about? We have two triangles to be discussed. One was urogenital, one is anal triangle. Right now, we are talking about which triangle? We are talking about urogenital triangle. And what was there in the urogenital triangle? What is the lateral wall in the urogenital triangle? if I just take you back here for a second. What was there in the lateral wall? What ramus? That is ischio-pubic ramus. So, be it superficial perennial pouch or it is deep perennial pouch, the lateral wall is same. It is the ischio-pubic ramus which will be there in the lateral wall. Right, so let me write down the boundaries of the deep perennial pouch first and then we will talk about the superficial. So let us talk about the boundaries of deep perennial pouch. So look at the diagram that you drew. So we said roof is by what? Roof is by the superior layer of urogenital diaphragm. Superior layer of urogenital diaphragm. And mind it, it's superior. It's not superficial. Superior layer of urogenital diaphragm. floor is by the perineal membrane floor is by perineal membrane and the wall is by that ligament called as the transverse perineal ligament transverse perineal ligament Posterior wall is nothing but the fusion of superior as well as inferior layer of urogenital diaphragm. Both the layers are fusing posterior. So that's a posterior wall, fusion of superior and inferior layer of urogenital diaphragm. And as we said nothing to worry about the lateral wall be it superficial pouch or deep pouch. Lateral wall is what? That is ischio pubic ramus. That is ischio pubic ramus. So these are the boundaries of the deep endal pouch. Superior layer of UGD, perineal membrane or inferior layer. We got a transverse penile ligament anteriorly. Posterior wall we have the fusion and on the sides we have the ischio pubic ramus. The urethra which is running inside, in the deep perineal pouch, the urethra that you see here, that urethra is what? That is membranous urethra. We have like prostatic urethra above, this is membranous and then obviously we have spongy urethra. So guys, if the injury is to the membranous urethra, the urine can accumulate or the extra decision of urine will be in what pouch? Deep perineal pouch. And deep perineal pouch is closed from all the sides. So you can note that point as well. that if the question says there is injury to membranous urethra. Now obviously membranous urethra is present where? It is present in deep adrenal pouch. So in case of injury to membranous urethra, the urine accumulation The urine accumulation will be seen in deep perineal pouch. And as I said, deep perineal pouch is closed from all the sides, so it is seen only in deep perineal pouch. So that is about the boundary of the deep panel pouch and what is the effect of the injury to the urethra in the deep pouch. Let me again take you back to this picture and first let's discuss what are the boundaries of superficial perineal pouch and then we'll again come back to the contents here. Now guys look at this picture. Now what are the boundaries here? For this superficial perineal pouch this time roof is by what? That is roof is by the perineal membrane. So roof is by the perineal membrane. Floor is by the colis fascia. Posterior wall is by the fusion of the perineal membrane and coli's fascia. You can see both are fusing posteriorly. Lateral wall doesn't change. Lateral wall is what? Ischio pubic ramus. But the big question is what is anterior wall? What is the anterior wall of superficial perineal pouch? So just think about it. Just take 5 seconds and think about what should be the anterior wall of superficial perineal pouch. Well, if you are thinking about the bulb of penis and structures like that, no, they are not the anterior wall, guys. First of all, in the superficial perineal pouch, there is no anterior wall. Anterior wall is open. And because anterior wall is open, that is why if the injury is to the spongy urethra, the urine can get accumulated in certain places like superficial pouch and scrotum. So first, let us write down the boundaries of the superficial perineal pouch and we will also talk about the extra vasogen of urine if the injury is to the spongy urethra. So for the superficial perennial pouch, boundaries. What are the boundaries? This time, we said anterior wall. That's the main thing, the anterior wall is what? It is deficient. That is the most important thing to remember here, that anterior wall is deficient. Anterior wall is deficient. Posterior wall is formed by the fusion of superior and inferior layer. Posterior wall is formed by the fusion of colis, fascia and perineal membrane. that you can check in your diagram that is fusion of collis, fascia and perineal membrane. Nothing changes in the lateral wall. Lateral wall is again the ischiopubic ramus. Lateral wall by ischiopubic ramus. This time roof is by the perineal membrane. or you can say the inferior layer of urogenital diaphragm, this time roof is by perineal membrane and floor is by colis fascia, floor is by the colis fascia, so these are the boundaries of the deep perineal, I am sorry superficial perineal pouch, anterior wall is deficient, posterior wall as you can see the fusion was there of the colis and the perineal membrane, lateral wall same ischiopubic ramus and the roof and the floor this time the perineal membrane was the floor for deep pouch but this panel membrane is the roof for superficial power so it's the perineal membrane which is present between the deep pouch and superficial pouch this this point will help you I'll tell you what But see this time it's a completely different story if we talk about the injury to the urethra. Now this urethra is a spongy urethra. If there is injury to this spongy urethra in the bulb of finesse, the urine can accumulate first clearly in where? In the superficial pedicle. perineal pouch and because superficial perineal pouch is not having the anterior wall so urine can go into what scrotum that is in the dartos layer dartos is a continuation of what scarpus fascia that means urine can continue in the anterior abdominal wall behind scarpus fascia and in extreme cases it can go till the level of clavicle and till the floor of axilla also Or urine can even go down in thigh till the scarpus fascia merges with fascia lata of the thigh. That is very much in the upper part of thigh. But yes, still it can go in the upper part of thigh as well. So what I am saying is that if the injury is to spongy urethra, but in the bulb of penis. That also is important in the bulb of penis. Injury. to spongy urethra where in the bulb of penis then urine accumulation can take place in now what could be the possible places where the urine can be seen that is obviously in the superficial perineal pouch number one No anterior wall, so you can see it can escape from the superficial perineal pouch into the scrotum inside the dartos leg. It can also go to the anterior abdominal wall till the axillary floor, that high, till the axillary floor. And it can also be seen in the upper part of thigh. it can be seen in the upper part of thigh till where? Till line called as Holden's line till line called as Holden's line what is Holden's line? Holden's line it signifies the fusion of the scarpus fascia and the facial lata that Holden's line it is a line which represents the fusion of scarpus fascia and the facial lata of the thigh that is is called as Holden's line. If you just draw up transverse line from pubic tubercle, that is Holden's line. You just look at the pubic tubercle on the radiograph and you draw a transverse line from that, that represents what? Holden's line. So till that, that means very much in the upper part of thigh, the urine can be seen. So that again is a very, very commonly asked question about the injury to the spongy urethra and where all we can have accumulation of urine, the superficial pouch, the scrotum, anterior abdominal wall, till the axillary floor and upper part of the thigh. So guys this is about the boundaries of the superficial and deep perineal pouch and about that what are the various scenario of the injuries to the membranous urethra or the spongy urethra. Now finally let's talk about the contents of the superficial perineal pouch. panel pouch and the contents of deep panel pouch and I'll tell you that one easy trick here when you read these contents in the textbook you will see there are array of structures which are written over there present in the superficial pouch and deep pouch so many nerves so many blood vessels well For the PG entrance exam point of view, you don't have to remember all of them. Because there are certain structures which are common to both the pouches. And common structures are not important. What is important is the structures which are either present in superficial pendular pouch or in the deep pendular pouch. And not shared in both of them. So keeping that in mind, let us see what structures would be there. Once again, I will take you back to this diagram here. and even before we start with the contents now look at this case if if if you look at this deep panel pouch now what is deep perennial pouch it is a potential space inside the urogenital diaphragm superior layer of or you can say the roof of the deep pouch is what? Superior layer of urogenital diaphragm. Floor is what? Inferior layer of urogenital diaphragm. That means in a way deep pineal pouch is a space inside urogenital diaphragm. So every time the question is asked on the... deep panel pouch you should actually think about they're asking about the urogenital diaphragm that that's an easy way to get the answer actually I'll tell you how so what is the content of the deep panel pouch now clearly one content inside is what that is membranous urethra now this membranous urethra will be covered by the sphincter also and that is what the sphincter urethra or the external urethral sphincter internal will be above this is external urethral sphincter that you will see here. Male gland that is Bulbo urethral gland will also be seen in the deep panel pouch. Let me just write B here that is Bulbo urethral gland. But yes the duct of the Bulbo urethral gland will pierce the perineal membrane to come down. That is Bulbo urethral gland. And one important muscle which you will see and which is quite obvious also, that is deep transverse perineal muscle. This was superficial transverse perineal muscle in the superficial pouch. Remember? Superficial transverse perineal muscle was below the perineal membrane. So you can see it below. Above the perineal membrane, that is what? Deep transverse perineal muscle. That here is a deep transverse perineal muscle. So let me write down these contents at one place and I'll show you some other pictures also to give you a better orientation. So guys we already talked about the boundaries. Let us talk about the contents. Contents of deep perennial pouch first. So what are the contents of deep panel pouch? We said first we got that is what urethra? That is membranous urethra. Then we have a sphincter around that is what? External urethral. sphincter you can also call it sphincter urethrae external urethral sphincter or sphincter urethrae. Bulbo urethral gland The male gland. Male gland is in deep perineal pouch. Female gland you will see in the superficial perineal pouch. So that is bulbo-urethral gland also called as a cowper's gland. So it is present in where? In the deep perineal pouch, the bulbo-urethral or cowper's gland. And what muscle? That was deep transverse perineal muscle. Deep transverse perineal muscle. Now trust me, if you look at the questions of the superficial and deep panel pouch, if it is a question on deep panel pouch, I can almost guarantee you the question will be like probably around these four contents only. And I'll tell you why it is around these four contents, why it is always about deep panel pouch. these four structures because majority of the nerves and vessels most of them if not all are piercing perineal membrane now if this is a perineal membrane we know perineal membrane is forming the floor of what pouch perineal membrane is a floor of which pouch? That is deep pouch. And the same perineal membrane is a roof of superficial pouch. So if any structure is piercing perineal membrane, it is content of what? Both superficial and deep pouch. So most of the blood vessels, the dorsal artery of the penis, the deep artery of the penis, duct of certain glands, urethra, artery to the bulb of the penis and artery to the urethra, so all these structures, whatever you see, membrane are the contents of deep pouch as well as superficial pouch. Well, I will put more light on it in a minute. Now, this is the content of the deep panel pouch. Now, what are the contents of superficial panel pouch? And to understand the content of superficial panel pouch, I am going to take you back to this picture here. What is this yellow colored membrane guys? The yellow color that highlighted that, what membrane is that? That is the perineal membrane. And just think about, perineal membrane is the roof of superficial pouch. That means everything that you see below perineal membrane, everything. that you see below perineal membrane, they are all contents of superficial perineal pouch. Whatever it is, bulb of penis, bulbospondyosis, crust of penis, ischiocavernosis, superficial transverse perineal muscle. And in case of female, also what gland? The female gland, that is Bartholin's gland, will also be in superficial pouch. So before I mark those, look at this comparative picture here. Look at this image guys. What is this here? This is the perineal membrane. The same thing that you do, that is perineal membrane. If this is perineal membrane, all these structures which are present below perineal membrane, everything that you have here, they are all in which pouch? Superficial pouch. So bulb and bulbous spongiosus, crust and ischiocavernosus, superficial transverse perineal muscle, and as I said in case of female, Bartholin's gland as well. So if I may write the contents of the superficial perineal pouch as well. Contents of superficial perineal pouch. We said everything below perineal membrane. Starting with bulb and bulbospongiosis. Bulb and bulbospongiosis. That is we are talking about the root of the penis. Root of the penis having bulb and bulbospongiosis. Crus and ischiocavernosus. Which other muscle? That is superficial transverse perineal muscle. Superficial transverse perineal muscle. And we said in case of female, in case of female, the Bartholin's gland. Bartholin's gland which is also called as what? This Bartholin's gland is also called as greater vestibular gland. If you are writing Bartholin's gland is also called as greater Vestibular gland that is also a content of what? Superficial panel pouch. Four contents of deep pouch, four contents of superficial pouch. I mean this is like more than 90% chance that you will be able to get do the question just by remembering these four content from here and these four content of the deep pouch here. Now coming to the point where I said there are certain structures, there are so many other structures which are present in both the pouches but we should not bother about them. The reason is guys, let me just make you understand this and I will have a very nice picture. that to explain. Now remember if this is a deep panel pouch, let us say this is a deep panel pouch and then we have this superficial panel pouch below, right, that is deep and the superficial panel pouch. Most of the nerves and vessels in this deep pouch and superficial pouch, they will come from where? They will come from the pudendal canal. This is a different topic in the ischial rectal fossa, that is pudendal canal. So guys, let's say this is a pudendal canal. Just a schematic diagram to explain you what other contents you should be careful about. This is a pudendal canal. What is there in the pudendal canal? We have pudendal nerve, we have internal pudendal vessels also. Pudendal nerve and internal pudendal vessels. Now look guys, if pudendal nerve and its branches, they are going from pudendal canal directly into which pouch? Deep pouch. And then they are piercing the perineal membrane. to go into what pouch? superficial pouch that means all these nerves and vessels which are piercing this perineal membrane if I specifically mark it with a red color this is perineal membrane so as I said anything piercing perineal membrane will be the content of both superficial perineal pouch below and deep pouch above. And the same goes for the blood vessels also. Internal pudendal artery will give off certain branches which will pierce this perineal membrane. And that again is the content of both the pouches. So if I just write it for you, if this is internal pudendal vessels, and this is the pudendal nerve, pudendal nerve coming from S2, S3, S4. Now these structures, they go through the pudendal canal, reach the deep pouch, and then most of them, they pierce the perineal membrane and the content of superficial pouch also. So I say, you should not be bothered about these structures, because they are in both. so most of the nerves and vessels when you see them in the option they are the content of both superficial and deep pouch now what structures you should be careful about which is there in one of the pouch only and not other some nerves and vessels you will see they are not piercing are not going into deep pouch oh if I if I highlight the deep pouch for you so we need to point out certain structures which are not in the deep pouch but present in superficial like we have nerves and vessels called as posterior scrotal nerves and vessels. We got some posterior scrotal nerves and vessels which will come like this. I hope you are able to understand this. These are posterior scrotal nerves and vessels. In female obviously posterior labial nerves and vessels. So one important structure that should be careful about is posterior scrotal or so called posterior labial nerves and vessels because these contents are present only in what? Only in superficial perineal pouch. You can see they are not entering into the D pouch and coming down. They are going directly into superficial pouch. And one content that you will see only in the deep pouch and not in superficial, that is a nerve called as dorsal nerve of the penis. Dorsal nerve of the penis or so called dorsal nerve of the clitoris. This is one structure that you should remember is present. only in deep perineal pouch rest everything is common so just don't worry whatever the deep artery the dorsal artery of the penis you know artery to the bulb they're all piercing perineal membrane and they are contents of pouches the only nerves and vessels just be bit careful about is a posterior scrotal and labial nerves and vessels and similarly dorsal now of the penis or so called dorsal now of the clitoris which is only in what out deep pouch right so the four important contents in the deep for important contents of superficial pouch plus these structures that we are writing which are specific to the superficial and deep pouch. If you remember them, I am pretty sure you will be able to tackle any question asked on the perennial pouches here. In fact, before going to the questions, I want to just discuss it on the picture, something that we already saw, the contents which are only in the superficial or only in the deep pouch. Now, just please get oriented to this image here. I need to enlarge it. it a bit for you. Look here guys, the first thing, this is the pelvic diaphragm, right, that is the highest layer, the pelvic diaphragm. Followed by, this is the superior layer of urogenital diaphragm. Just look at the pointer very carefully, this is the superior layer of urogenital diaphragm. And this here is the perineal membrane or the inferior layer of urogenital diaphragm, this one. So obviously what pouch is that? That is the deep perineal pouch. And if this is deep perineal pouch, this pouch here below, this one, is what? Superficial perineal pouch. Now, if you look at this image here, you can see all these nerves and vessels, look at these blood vessels and all they are piercing the perineal membrane, so they are content of both pouches. But as I said, the structures we need to be careful about, nerve is not shown in this image. nerve of the penis will go through the deep perineal pouch and will go directly on the dorsal aspect of the penis so it is only the content of what pouch? Deep perineal pouch but look at these nerves and vessels can you can you not the nerve at least vessel we can see here these are the posterior scrotal vessels that you see which is coming behind the perineal membrane and then going directly into what pouch? Superficial perineal pouch so that's what we said that posterior scrotal and labial norms and vessels only content of soup superficial pouch, dorsal nerve of the penis is the content of only deep perineal pouch. Let us discuss some questions on the perineum. And these are the standard questions which are usually asked in the exam. And as I said, it's a very important topic, especially for the Central Institute. So make sure you try out as many questions as possible. as you can on this now see the question says that urogenital diaphragm is made up of the following except and see what I told you that when you see urogenital diaphragm think of what which pouch deep pedal pouch deep deep pendular pouch is between superior layer and inferior layer of urogenital diaphragm. So, if you think of the deep pendular pouch, that which of these have nothing to do with the deep pendular pouch, you will get the answer. And which of the following structure is not related to the deep pendular pouch, that is the colis fascia. Colis fascia was forming what? It was forming the floor of the superficial pendular pouch. So, obviously it has nothing to do with the deep pouch or you can say in other words to the urogenital diaphragm. Another question here, it says injury to the male urethra in the bulb of penis, we discussed that, causes the urine to accumulate in all except. Now, we already know that urine can get accumulated in the superficial pendulum. pouch which is in the option it's there urine can be accumulated in what it can go into the anterior abdominal wall it is there and it can also go into the upper part of the thigh it will not go into the space of resus what a space of reason it's a retro pubic space in front of the bladder just behind pubic symphysis but in front of the urinary bladder that space is called a space of rhesus so you cannot have accumulation of urine in the space of rhesus if the injury is to the urethra that is a space of rhesus is the answer to this question Another question which was asked twice that all are the contents of deep pedal pouch except. See, now we can use that technique here. All are the contents of deep pedal pouch except. Now, what is not the content? Now, first of all, look at this option, guys. It says dorsal. nerve of the penis. We said dorsal nerve of the penis is the content of the deep panel pouch. Not in the superficial but it is there in the deep panel pouch. So it cannot be the answer. Sphincter urethrae also called as external urethral sphincter. Again external urethral sphincter. external urethral sphincter is a content of deep mandible pouch covering the membranous urethra. Bulbourethral gland that is a male gland, male gland is in deep pouch, female gland is superficial pouch. So obviously what is the answer? That is the bulb. bulb or the root of the penis, bulbous, spongiosus, ischiocavernosus, all those structures are present below the pendular membrane and they are the content of superficial pouch and that is what the question is asking, it is asking about accept. And then we got this another question which says, injury to which of the following deep part of the perineal body can lead to the rectocele, cystocele and the urinary incontinence? Now, which part of the perineal body? There are so many muscles which are contributing to perineal body. All those bulbous spongiosus and transverse perineal muscle and then we have external sphincter. also to the perineal body. But he said which component of the perineal body? That which means muscle. Now what was the muscle of pelvic diaphragm which was closest to all the opening, to the urethra, to the vagina, to the rectum and forming all those muscular cells? slings around them and that was what? Pubococcygeus. So pubococcygeus muscle which forms these modifications called as puborectalis, pubovaginalis, pubourethralis. So it's this muscle, it is this component of the perineal body or you can say it is this component of the pelvic diaphragm injury to which can lead to what? The rectocele, the cystocele and the urinary incontinence. And one more question which I want to discuss here that is the vaginal sphincter this also is the question asked in the aims that vaginal sphincter is formed by all except well when you see vaginal sphincter is formed by all except look at the bulbous pondous muscle it is also covering the bulb of the vestibule so it is covering forming the bulb of the vestibule so it is forming the part of the vaginal sphincter also pubovaginalis the name suggests pubovaginalis it is obviously the modification of the pubococcygeus muscle and circling the vagina it's also there So, answer is in between external and internal urethral sphincter. Well, there should be no confusion in this because females do not have internal urethral sphincter. Females do not have internal urethral sphincter. Internal urethral sphincter in male is to prevent the sperm from going back into the bladder. It prevents the retrograde ejaculation. That's why it is there. So during ejaculation, the internal urethral sphincter... will close and it will allow the sperm only to go down into the spongy urethra but not back into the bladder. So please note that internal urethral sphincter is absent in female and that is obviously not contributing to the part of the vaginal system. sphincter. So that is about the perineal pouches. I hope you understood the boundaries and the contents and how to deal with especially so many nerves and vessels are there. So only few nerves and vessels that you need to remember in the perineal pouches and I am sure you will be able to do probably every single question on this topic.

It's not very good for most of the people. I mean we are not very much oriented to how exactly the structures are located, where we have the urogenital triangle, how is the anal triangle formed, how these triangles are connected to each other, is there any connection between the ischial rectal force of both sides. So in the perineum part, the important thing is the orientation. And we first will start with the boundaries of the perineum. If I say, okay, you read the perineum by yourself, you probably will not pay much attention to the boundaries.

You will say, okay, pouches are very important. Let's talk about the deep pouches and superficial pouches. But remember one thing, until unless you know the exact boundaries of the perineum, you will always find it difficult to understand all the perineal pouches or be it anal triangle.

So let's start with this picture where you're looking at the pelvic bone from the inferior aspect. So this basically is a lithotomy view. So guys look at this structure starting from here this is obviously is what that is pubic symphysis. We got the pubic bone that is a pubic bone. This ramus here that is a ischio-pubic ramus.

This is ischio-pubic ramus. This tuberosity that is ischial tuberosity here and stretching from ischial tuberosity to the sacrum that ligament that is what sacro-tuberous ligament. I repeat again that is a pubic symphysis that is pubic bone. The ramus is what ischio-pubic ramus.

We got this ischial tuberosity and stretching from the ischial tuberosity till the sacrum, the ligament is sacro-tuberous ligament. Now this is the boundary of the perineum in which we have everything, all this pelvic diaphragm, urogenital diaphragm and triangle, all we need to discuss inside. The second important thing about perineum is how we divide the perineum.

Now look at my hand where I am putting it guys. If I put my hand like this. That means if a line is passing from the anterior margin of ischial tuberosity here, now that will divide the perineum in two triangles.

The small triangle which is present in front, that is called as the urogenital triangle because all the urinary structures and the genital structures will be seen there. You will see the opening of the urethra, you will see opening of the vagina, the bulb of the penis, the crust of the penis, all are located in that region, so we call it urogenital triangle. Whereas this triangle behind, which is behind this level of ischial tuberosity, this is called as anal triangle. And all we have inside anal triangle is the anal canal. And both the side of anal canal you will see ischio-rectal or so called ischio-anal fossa.

So that is what we are going to start with. We will start with the boundaries and we will bend up in the perineum. Before we start with this topic and go into detail of that, also remember one thing. When you start reading perineum in any of the textbooks, they have explained perineum starting from the skin and going upwards.

Like they first will talk about the skin, then the superficial fascia, the colis fascia and so on. And yeah, this is how it should be. I mean, we have to dissect from inferior to superior only and that's how it is explained. But I very, very strongly feel that if you understand the perineum from superior to inferior, it is much better view, you have a better orientation of the perineum. Like, if you start from pelvic diaphragm, which is the highest layer in the perineum, or you can say it is the superior most structure in the perineum, and you keep on looking what is below that pelvic diaphragm and then below, till we reach the skin and the fascia.

So that is how we are going to approach. We will start with the pelvic diaphragm, that is the first layer, and then we will come to the triangle below that is urogenital triangle and all those things. Third important thing about perineum apart from this boundary and how we'll approach it is that when you talk about perineum it is in the lithotomy.

So that means you are seeing it from the inferior aspect. Now when you see it from the inferior aspect, everything that you find first, that is superficial, is actually inferior. We have to start dissecting from inferior to superior. So skin, then fascia, then that means we are going deeper.

The more we go above, the more we go up, that means we are going deep. So every time I use the word superficial in the perineum, that means it has to be below. It has superficial, superficial means it is down. But when I say deep, deep layer of urogenital diaphragm, deep perineal pouch, then we are talking about something which is above, right?

So superficial is below and deep is above in the perineum because the approach is from inferior to superior only. So keeping these general things in mind, the boundaries of the perineum, how we'll approach it, that is we'll approach it from superior to inferior and everything in the inferior, everything which is inferior in the perineum is what? Superficial and deep is above.

Let's start with this topic. Okay, so I'll... As already we discussed the boundaries of the perineum, so if I just quickly go through it once again, that was the pubic symphysis. Here is the pubic bone.

This is ischio-pubic rami, ischio-pubic ramus. This is the ischial tuberosity, sacro-tuberous ligament, and of course that is the sacrum and coccygeal vertebrae. And the important point is we said if you draw a line, imaginary line from the anterior margin of the ischial tuberosity that is dividing the perineum in these two important triangles.

This is the urogenital triangle that you see in front having all the urinary and the genital structure that is urogenital triangle. And the triangle behind this is having anal canal and on either side we have ischioanal fossa. So that is called as the anal triangle.

Our topic here is the perineal pouches. So we will be focusing on the urogenital triangle. So as we said, let us start with the highest layer in the perineum and then we will keep on building it downwards.

So what was the highest layer? The highest layer is the pelvic diaphragm. So that is what we are going to start with.

pelvic diaphragm. So I'm just going to draw the schema of what we just saw. So the boundaries are somewhat like we have this pubic symphysis and ischio-pubic ramus.

Then we got this sacrum and coccygeal vertebrae present here and that is the sacro-tuberous ligament. Just drawing the boundary of the perineum. This is the East chill tuberosity.

Now what is Pelvic Diaphragm? Pelvic Diaphragm is a combination of three muscles coming from three different parts of hip bone and all of them are converging to the coccygeal vertebrae. Now this here is the coccyx, this is the coccygeal vertebrae and you will see the muscles coming from three different parts and all of them are converging here. Like there is a muscle coming from the pubic bone that is called as pubococcygeus.

There is a muscle coming from the ileum. or mainly from the obturator fascia that is called as iliococcygeus and similarly we have this ischio coccygeus now these are three muscles together which are called as pelvic diaphragm this is the pubococcygeus this here is iliococcygeus and then we got the ischio coccyges, ischio coccyges is simply called as coccyges also either you call it ischio coccyges or just coccyges all these three muscles together are called as what? pelvic diaphragm so pelvic diaphragm is basically the combination of these three muscles the pubo, ilio and ischio coccyges and you must have seen that pelvic diaphragm and levator anion These are the two words which are used interchangeably sometimes. But there is a slight difference guys.

When you say pelvic diaphragm, you are counting all the three muscles. But when you say levator ani, then you are talking about only pubococcygeus and iliococcygeus but not ischiococcygeus. Ischiococcygeus in human, it's a kind of vestigial muscle only. Because ischiococcygeus in certain lower animals, I mean it is for the movement of the tail. So in human it is not having any functional importance.

So, it is the pubococcygeus muscle and the iliococcygeus muscle which together are referred as what levator anion. These are the two muscles which are together called as levator anion. Just remember this difference here first that pelvic diaphragm is like all the three muscles together but levator and eye is just pubococcygeus and ileococcygeus.

Now let us imagine this as a section of the female perineum. Now if this is a section of female perineum we will expect to have three major openings in the pelvic diaphragm one for the urethra for the vagina and for the rectum. So we got these three major opening that is for the the urethra, vagina and the rectum.

And see what is the muscle which is closest to all the three openings. The muscle out of the three in the pelvic diaphragm which is closest is what? Pubic Oxygen.

Therefore you will see the pubic oxygen muscle is forming the sling around all these openings. So these muscles which are acting as a functional sphincters around these major openings are basically extension of pubic oxygen. So that is one question here that what? are the modifications of pubococcyges. So, one you see it around the urethra, one you see around the vagina and the one that you see here is around the rectum.

So, this is called as pubourethralis, that is pubourethralis. We got puboviginalis and this is the pupil Pupourethralis covering the urethra you can see, pubovaginalis around the vagina and the puborectalis which is maintaining that anorectal angle that is puborectalis all these three muscles are the modifications of all of them are the modification of which muscle? They are all modification of pubo. That is one important point, one important question here that what muscles are the or what are the modifications or extensions of pubococcyges. And out of all these specially this one the puborectalis, it is very very important as we said puborectalis is the muscle which maintains that anorectal angle and it is also called as muscle of continence.

The muscle of the rectal continence, the puborectalis it maintains the anorectal angle and called as muscle of So, this is the first thing guys that is we started with the highest layer that is pelvic diaphragm. What are three muscles forming pelvic diaphragm and the innermost muscle is forming all these modifications. Now, as we said we will start from the superior and we will keep on going downwards. So, let us go below the pelvic diaphragm and remember what we said below means what we are going superficial.

So, going below means we are going superficial. Now when you go below the pelvic diaphragm, there is another diaphragm you will see. If I just once again sketch these boundaries roughly, right?

These are the boundaries. So below the pelvic diaphragm, there is another diaphragm which is present in this triangle here. Now what is this triangle guys? This triangle was urogenital triangle, right?

So if this is a urogenital triangle, obviously the diaphragm will also be called as urogenital diaphragm. So please remember that we have a pelvic diaphragm. There is a pelvic diaphragm first. You are seeing it from inferior aspect. There is a pelvic diaphragm first.

And below pelvic diaphragm, now we have another diaphragm that is only in the urogenital triangle. And we call it what? Urogenital diaphragm.

Please remember, urogenital diaphragm is a double layered structure. we have a superior layer of urogenital diaphragm and then we have inferior layer of urogenital diaphragm. And because we are saying you are seeing it from the inferior aspect, you are seeing it from the inferior aspect.

So, you are looking at which layer? Is it superior or inferior? So, you are looking at what? Inferior layer of urogenital diaphragm.

There will be one more above it that is superior layer exactly like this. But this here, please note is the inferior layer of urogenital diaphragm. This is inferior layer of I am writing UGD, urogenital diaphragm, inferior layer of urogenital diaphragm which is also called as perineal membrane.

Do remember this name, we will be using it very frequently in this topic. Inferior layer of urogenital diaphragm which is also called as what? Perineal membrane.

So how many layers till now guys? How many layers? Three.

Starting from superior to inferior, that is pelvic diaphragm. Next, we have superior layer of urogenital diaphragm. And the one that you are looking at right now here is the inferior layer of urogenital diaphragm.

So till now, we talked about three layers. Now let us say this is a section of the male perineum. So what you will see here, you will see the bulb of the penis and the crust of the penis with their respective muscles around them. Bulb of the penis, we have a muscle around the bulb of the penis, that is muscle on the bulb.

it's not a bipineate muscle these are two muscle meeting at the midline rapid and you also will appreciate a muscle present on the cross they are below the urogenital diaphragm of course that's why I'm drawing here because it is below and I want you guys to think about see what is what should be the name of these muscles now this here is the bulb just writing bulb because in case of female it will be like bulb of vestibule so of penis or bulb of vestibule but what is the muscle around this bulb this muscle is not only covering the bulb of penis the muscle is going forward and also covering the spongy urethra so the muscle is what this is bulbospongiosis that's very very important to remember the name here that is bulbospongiosis the muscle on the bulb of penis that is bulbospongiosis Now this is the crust of the penis and the muscle on the crust of the penis is called as ischiocavernosis. The muscle will come from the ischium, look this is the ischium here and this muscle from the ischium will go and cover the cavernous portion of the penis which is filled with the blood in the erection. So that is ischiocavernosis. That is ischiocavernosis.

So we have a muscle on the bulb called as bulbospongiosis and the muscle on the crest which is called as ischiocavernosis. There also is a muscle running transversely in the perineum. Now look at this muscle guys, it is present transversely in the perineum.

Now first of all it is running transversely in the perineum, so we call it transverse perineal muscle. But this transverse perineal muscle is present below the urogenital diaphragm. So it is superficial or deep? We said everything, whatever is below is what? It is superficial.

So this muscle is called a superficial transverse perineal muscle. So the muscle that you are looking at here, this is Superficial Transverse Perineal Muscle, that is a Superficial Transverse Perineal Muscle, that is Superficial Transverse Perineal Muscle. Whereas if you look at the anal triangle, although we are not discussing anal triangle in this section, but if this is anal triangle, we got an anal canal and we also got a muscle around it that is external anal sphincter. That is the external anal sphincter.

the muscle around the inner canal that is external inner sphincter and this point where all these or this fibromuscular node where all these muscles are converging is a major major support for the pelvic viscera called as perineal body. So this is what you are looking at till now. We started with the pelvic diaphragm.

If I just quickly go through this once again guys, the pelvic diaphragm. What was below pelvic diaphragm? Let's count all the layers individually.

Below pelvic diaphragm, it was superior layer of urogenital diaphragm. Then we have inferior layer of urogenital diaphragm which is also called as perineal membrane. Below perineal membrane, you can see the bulb of the penis and crust of the penis which are covered with their respective muscles. Bulbospongiosis, ischiocavernosis. we also have superficial transverse perineal muscle and finally if below these muscles I will put a fascia that is colis fascia that will complete the layer of perineum for me so starting from pelvic diaphragm till the colis fascia this is all the superficial pouches and deep pouches the one we have to discuss are present between these layers only so we start with pelvic diaphragm and the inferior most we have this colis fascia but to reach the colis fascia where the colis fascia is and how it is seen there, we need to take an important section that is a sagittal section.

It's a mid-sagittal section we have to take which will go through the bulb and the shaft of the penis here. Okay, so let's take a sagittal section. Let us take a sagittal section to understand this perineum well.

So when you take a sagittal section, the highest layer is the pelvic diaphragm. So let's start from here. That is a pelvic diaphragm. That is a topmost layer. Let me write this PD for the pelvic diaphragm.

Below pelvic diaphragm, we got this superior layer of urogenital diaphragm. And then even below that, we got this inferior layer of urogenital diaphragm. Like this. And what you see that superior layer and the inferior layer of urogenital diaphragm, they are both fusing anteriorly and posteriorly with each other. This is the superior layer, if I may write it here.

This is superior layer of urogenital diaphragm and this is the inferior layer of urogenital diaphragm which is also called as what perineal membrane. So let me write that alternative name also that is perineal membrane. Because it is a mid-sigital section, so the section will go from the crust of the penis or the bulb of the penis.

It will go from the bulb and the shaft of the penis. We are taking a sigital section, mid-sigital section. So guys, let us say this here is the bulb and the shaft of the penis.

And there is the urethra which is running through. So that's the urethra which is running through. The bulb obviously will be covered with a muscle around. That is the bulbospondylus. I'm not drawing that muscle.

And now coming to the last layer. See, we said that... starting from pelvic diaphragm we need to reach the lowest layer that is what?

Colleus fascia. So what is colleus fascia and where it is? For that I again have to start from the anterior abdominal wall. I hope you remember that anterior abdominal wall is devoid of deep fascia and we have two layers of superficial fascia only on the anterior abdominal wall namely campers fascia and scarpus fascia. So guys let us say this is the scarpus fascia Now this scarpus fascia will continue in the scrotum as the dartos muscle and fascia and that will continue posteriorly as collis fascia.

So it's a scarpus fascia only which you see will continue in the scrotum as the dartos muscle and fascia. And this datus muscle and the fascia which is forming a layer of a scrotum will continue towards the perineum as what? Collis fascia.

So in a way they are all same. The scarpas will form the datus and that will continue behind as what? Collis fascia. And this collis fascia will Merge with the descending layer of perineal membrane.

As you can see, I drew it like this, let me put an arrow. So, it's the perineal membrane which you will see fusing with the colis fascia and closing that space behind. So, one thing that you should be able to understand from this section, that there is a space present between the superior layer and inferior layer of urogenital diaphragm, that is one. And we also have a space which is present below the perineal membrane, or you can say below the urogenital diaphragm. And these are actually the two pouches.

Try to write it where I am writing it. This is the deep perennial pouch. It is above, so it is deep. So we have a deep perennial pouch.

And the one which is present below, that is superficial perennial pouch. The pouch above is deep perennial pouch. And the pouch below, that is superficial perennial pouch. We got to discuss the boundaries and everything about these pouches. But this is deep and superficial perennial pouch.

Let me introduce you to one more terminology here. That superior layer and inferior layer of the urogenital diaphragm, when they are fused anteriorly, at this fusion we have a ligament and that ligament is called as transverse perineal ligament. This is called as a transverse perineal ligament.

The transverse perineal ligament. So guys this is one very very important subject section which will give you a good orientation about that how the deep perennial pouch is formed and how superficial perennial pouch is formed. So I will talk about the contents of the superficial and deep perennial pouch in a while.

Let us first talk about the boundaries. and the effect of the injury to the urethra in those particular pouches, in the deep pouch and the superficial pouch. So using this diagram, let us first talk about the deep perineal pouch. Now, even before we write, I want all of you to look at this. screen.

Guys, deep panel pouch, roof is by what? It's clearly by superior layer of urogenital diaphragm, this one. Floor is by what?

Floor is by the perineal membrane. Very clear. Posterior wall, same.

The fusion of the superior layer and inferior layer, they are forming the posterior wall of the deep pouch. What is there in the anterior wall? That is transverse perineal ligament is in the anterior wall.

So, it's very clear from this picture that the roof, floor, anterior wall, posterior wall is by what structures? But But what about the lateral wall? In the sagittal section, you cannot see the lateral wall.

What should be the lateral wall of the deep perineal pouch and also for superficial perineal pouch? Think about it. See, what triangle are we talking about? We have two triangles to be discussed.

One was urogenital, one is anal triangle. Right now, we are talking about which triangle? We are talking about urogenital triangle. And what was there in the urogenital triangle? What is the lateral wall in the urogenital triangle?

if I just take you back here for a second. What was there in the lateral wall? What ramus?

That is ischio-pubic ramus. So, be it superficial perennial pouch or it is deep perennial pouch, the lateral wall is same. It is the ischio-pubic ramus which will be there in the lateral wall. Right, so let me write down the boundaries of the deep perennial pouch first and then we will talk about the superficial.

So let us talk about the boundaries of deep perennial pouch. So look at the diagram that you drew. So we said roof is by what?

Roof is by the superior layer of urogenital diaphragm. Superior layer of urogenital diaphragm. And mind it, it's superior. It's not superficial. Superior layer of urogenital diaphragm.

floor is by the perineal membrane floor is by perineal membrane and the wall is by that ligament called as the transverse perineal ligament transverse perineal ligament Posterior wall is nothing but the fusion of superior as well as inferior layer of urogenital diaphragm. Both the layers are fusing posterior. So that's a posterior wall, fusion of superior and inferior layer of urogenital diaphragm.

And as we said nothing to worry about the lateral wall be it superficial pouch or deep pouch. Lateral wall is what? That is ischio pubic ramus. That is ischio pubic ramus. So these are the boundaries of the deep endal pouch.

Superior layer of UGD, perineal membrane or inferior layer. We got a transverse penile ligament anteriorly. Posterior wall we have the fusion and on the sides we have the ischio pubic ramus. The urethra which is running inside, in the deep perineal pouch, the urethra that you see here, that urethra is what? That is membranous urethra.

We have like prostatic urethra above, this is membranous and then obviously we have spongy urethra. So guys, if the injury is to the membranous urethra, the urine can accumulate or the extra decision of urine will be in what pouch? Deep perineal pouch.

And deep perineal pouch is closed from all the sides. So you can note that point as well. that if the question says there is injury to membranous urethra.

Now obviously membranous urethra is present where? It is present in deep adrenal pouch. So in case of injury to membranous urethra, the urine accumulation The urine accumulation will be seen in deep perineal pouch. And as I said, deep perineal pouch is closed from all the sides, so it is seen only in deep perineal pouch. So that is about the boundary of the deep panel pouch and what is the effect of the injury to the urethra in the deep pouch.

Let me again take you back to this picture and first let's discuss what are the boundaries of superficial perineal pouch and then we'll again come back to the contents here. Now guys look at this picture. Now what are the boundaries here? For this superficial perineal pouch this time roof is by what?

That is roof is by the perineal membrane. So roof is by the perineal membrane. Floor is by the colis fascia.

Posterior wall is by the fusion of the perineal membrane and coli's fascia. You can see both are fusing posteriorly. Lateral wall doesn't change.

Lateral wall is what? Ischio pubic ramus. But the big question is what is anterior wall? What is the anterior wall of superficial perineal pouch? So just think about it.

Just take 5 seconds and think about what should be the anterior wall of superficial perineal pouch. Well, if you are thinking about the bulb of penis and structures like that, no, they are not the anterior wall, guys. First of all, in the superficial perineal pouch, there is no anterior wall. Anterior wall is open.

And because anterior wall is open, that is why if the injury is to the spongy urethra, the urine can get accumulated in certain places like superficial pouch and scrotum. So first, let us write down the boundaries of the superficial perineal pouch and we will also talk about the extra vasogen of urine if the injury is to the spongy urethra. So for the superficial perennial pouch, boundaries. What are the boundaries? This time, we said anterior wall.

That's the main thing, the anterior wall is what? It is deficient. That is the most important thing to remember here, that anterior wall is deficient. Anterior wall is deficient.

Posterior wall is formed by the fusion of superior and inferior layer. Posterior wall is formed by the fusion of colis, fascia and perineal membrane. that you can check in your diagram that is fusion of collis, fascia and perineal membrane. Nothing changes in the lateral wall. Lateral wall is again the ischiopubic ramus.

Lateral wall by ischiopubic ramus. This time roof is by the perineal membrane. or you can say the inferior layer of urogenital diaphragm, this time roof is by perineal membrane and floor is by colis fascia, floor is by the colis fascia, so these are the boundaries of the deep perineal, I am sorry superficial perineal pouch, anterior wall is deficient, posterior wall as you can see the fusion was there of the colis and the perineal membrane, lateral wall same ischiopubic ramus and the roof and the floor this time the perineal membrane was the floor for deep pouch but this panel membrane is the roof for superficial power so it's the perineal membrane which is present between the deep pouch and superficial pouch this this point will help you I'll tell you what But see this time it's a completely different story if we talk about the injury to the urethra. Now this urethra is a spongy urethra.

If there is injury to this spongy urethra in the bulb of finesse, the urine can accumulate first clearly in where? In the superficial pedicle. perineal pouch and because superficial perineal pouch is not having the anterior wall so urine can go into what scrotum that is in the dartos layer dartos is a continuation of what scarpus fascia that means urine can continue in the anterior abdominal wall behind scarpus fascia and in extreme cases it can go till the level of clavicle and till the floor of axilla also Or urine can even go down in thigh till the scarpus fascia merges with fascia lata of the thigh. That is very much in the upper part of thigh. But yes, still it can go in the upper part of thigh as well.

So what I am saying is that if the injury is to spongy urethra, but in the bulb of penis. That also is important in the bulb of penis. Injury. to spongy urethra where in the bulb of penis then urine accumulation can take place in now what could be the possible places where the urine can be seen that is obviously in the superficial perineal pouch number one No anterior wall, so you can see it can escape from the superficial perineal pouch into the scrotum inside the dartos leg.

It can also go to the anterior abdominal wall till the axillary floor, that high, till the axillary floor. And it can also be seen in the upper part of thigh. it can be seen in the upper part of thigh till where? Till line called as Holden's line till line called as Holden's line what is Holden's line? Holden's line it signifies the fusion of the scarpus fascia and the facial lata that Holden's line it is a line which represents the fusion of scarpus fascia and the facial lata of the thigh that is is called as Holden's line.

If you just draw up transverse line from pubic tubercle, that is Holden's line. You just look at the pubic tubercle on the radiograph and you draw a transverse line from that, that represents what? Holden's line.

So till that, that means very much in the upper part of thigh, the urine can be seen. So that again is a very, very commonly asked question about the injury to the spongy urethra and where all we can have accumulation of urine, the superficial pouch, the scrotum, anterior abdominal wall, till the axillary floor and upper part of the thigh. So guys this is about the boundaries of the superficial and deep perineal pouch and about that what are the various scenario of the injuries to the membranous urethra or the spongy urethra. Now finally let's talk about the contents of the superficial perineal pouch. panel pouch and the contents of deep panel pouch and I'll tell you that one easy trick here when you read these contents in the textbook you will see there are array of structures which are written over there present in the superficial pouch and deep pouch so many nerves so many blood vessels well For the PG entrance exam point of view, you don't have to remember all of them.

Because there are certain structures which are common to both the pouches. And common structures are not important. What is important is the structures which are either present in superficial pendular pouch or in the deep pendular pouch. And not shared in both of them.

So keeping that in mind, let us see what structures would be there. Once again, I will take you back to this diagram here. and even before we start with the contents now look at this case if if if you look at this deep panel pouch now what is deep perennial pouch it is a potential space inside the urogenital diaphragm superior layer of or you can say the roof of the deep pouch is what? Superior layer of urogenital diaphragm. Floor is what?

Inferior layer of urogenital diaphragm. That means in a way deep pineal pouch is a space inside urogenital diaphragm. So every time the question is asked on the... deep panel pouch you should actually think about they're asking about the urogenital diaphragm that that's an easy way to get the answer actually I'll tell you how so what is the content of the deep panel pouch now clearly one content inside is what that is membranous urethra now this membranous urethra will be covered by the sphincter also and that is what the sphincter urethra or the external urethral sphincter internal will be above this is external urethral sphincter that you will see here. Male gland that is Bulbo urethral gland will also be seen in the deep panel pouch.

Let me just write B here that is Bulbo urethral gland. But yes the duct of the Bulbo urethral gland will pierce the perineal membrane to come down. That is Bulbo urethral gland. And one important muscle which you will see and which is quite obvious also, that is deep transverse perineal muscle. This was superficial transverse perineal muscle in the superficial pouch.

Remember? Superficial transverse perineal muscle was below the perineal membrane. So you can see it below. Above the perineal membrane, that is what?

Deep transverse perineal muscle. That here is a deep transverse perineal muscle. So let me write down these contents at one place and I'll show you some other pictures also to give you a better orientation. So guys we already talked about the boundaries.

Let us talk about the contents. Contents of deep perennial pouch first. So what are the contents of deep panel pouch? We said first we got that is what urethra? That is membranous urethra.

Then we have a sphincter around that is what? External urethral. sphincter you can also call it sphincter urethrae external urethral sphincter or sphincter urethrae.

Bulbo urethral gland The male gland. Male gland is in deep perineal pouch. Female gland you will see in the superficial perineal pouch.

So that is bulbo-urethral gland also called as a cowper's gland. So it is present in where? In the deep perineal pouch, the bulbo-urethral or cowper's gland. And what muscle? That was deep transverse perineal muscle.

Deep transverse perineal muscle. Now trust me, if you look at the questions of the superficial and deep panel pouch, if it is a question on deep panel pouch, I can almost guarantee you the question will be like probably around these four contents only. And I'll tell you why it is around these four contents, why it is always about deep panel pouch.

these four structures because majority of the nerves and vessels most of them if not all are piercing perineal membrane now if this is a perineal membrane we know perineal membrane is forming the floor of what pouch perineal membrane is a floor of which pouch? That is deep pouch. And the same perineal membrane is a roof of superficial pouch. So if any structure is piercing perineal membrane, it is content of what?

Both superficial and deep pouch. So most of the blood vessels, the dorsal artery of the penis, the deep artery of the penis, duct of certain glands, urethra, artery to the bulb of the penis and artery to the urethra, so all these structures, whatever you see, membrane are the contents of deep pouch as well as superficial pouch. Well, I will put more light on it in a minute. Now, this is the content of the deep panel pouch. Now, what are the contents of superficial panel pouch?

And to understand the content of superficial panel pouch, I am going to take you back to this picture here. What is this yellow colored membrane guys? The yellow color that highlighted that, what membrane is that? That is the perineal membrane.

And just think about, perineal membrane is the roof of superficial pouch. That means everything that you see below perineal membrane, everything. that you see below perineal membrane, they are all contents of superficial perineal pouch.

Whatever it is, bulb of penis, bulbospondyosis, crust of penis, ischiocavernosis, superficial transverse perineal muscle. And in case of female, also what gland? The female gland, that is Bartholin's gland, will also be in superficial pouch.

So before I mark those, look at this comparative picture here. Look at this image guys. What is this here? This is the perineal membrane.

The same thing that you do, that is perineal membrane. If this is perineal membrane, all these structures which are present below perineal membrane, everything that you have here, they are all in which pouch? Superficial pouch.

So bulb and bulbous spongiosus, crust and ischiocavernosus, superficial transverse perineal muscle, and as I said in case of female, Bartholin's gland as well. So if I may write the contents of the superficial perineal pouch as well. Contents of superficial perineal pouch. We said everything below perineal membrane. Starting with bulb and bulbospongiosis.

Bulb and bulbospongiosis. That is we are talking about the root of the penis. Root of the penis having bulb and bulbospongiosis. Crus and ischiocavernosus.

Which other muscle? That is superficial transverse perineal muscle. Superficial transverse perineal muscle.

And we said in case of female, in case of female, the Bartholin's gland. Bartholin's gland which is also called as what? This Bartholin's gland is also called as greater vestibular gland.

If you are writing Bartholin's gland is also called as greater Vestibular gland that is also a content of what? Superficial panel pouch. Four contents of deep pouch, four contents of superficial pouch.

I mean this is like more than 90% chance that you will be able to get do the question just by remembering these four content from here and these four content of the deep pouch here. Now coming to the point where I said there are certain structures, there are so many other structures which are present in both the pouches but we should not bother about them. The reason is guys, let me just make you understand this and I will have a very nice picture.

that to explain. Now remember if this is a deep panel pouch, let us say this is a deep panel pouch and then we have this superficial panel pouch below, right, that is deep and the superficial panel pouch. Most of the nerves and vessels in this deep pouch and superficial pouch, they will come from where? They will come from the pudendal canal. This is a different topic in the ischial rectal fossa, that is pudendal canal.

So guys, let's say this is a pudendal canal. Just a schematic diagram to explain you what other contents you should be careful about. This is a pudendal canal.

What is there in the pudendal canal? We have pudendal nerve, we have internal pudendal vessels also. Pudendal nerve and internal pudendal vessels. Now look guys, if pudendal nerve and its branches, they are going from pudendal canal directly into which pouch?

Deep pouch. And then they are piercing the perineal membrane. to go into what pouch? superficial pouch that means all these nerves and vessels which are piercing this perineal membrane if I specifically mark it with a red color this is perineal membrane so as I said anything piercing perineal membrane will be the content of both superficial perineal pouch below and deep pouch above.

And the same goes for the blood vessels also. Internal pudendal artery will give off certain branches which will pierce this perineal membrane. And that again is the content of both the pouches.

So if I just write it for you, if this is internal pudendal vessels, and this is the pudendal nerve, pudendal nerve coming from S2, S3, S4. Now these structures, they go through the pudendal canal, reach the deep pouch, and then most of them, they pierce the perineal membrane and the content of superficial pouch also. So I say, you should not be bothered about these structures, because they are in both. so most of the nerves and vessels when you see them in the option they are the content of both superficial and deep pouch now what structures you should be careful about which is there in one of the pouch only and not other some nerves and vessels you will see they are not piercing are not going into deep pouch oh if I if I highlight the deep pouch for you so we need to point out certain structures which are not in the deep pouch but present in superficial like we have nerves and vessels called as posterior scrotal nerves and vessels.

We got some posterior scrotal nerves and vessels which will come like this. I hope you are able to understand this. These are posterior scrotal nerves and vessels. In female obviously posterior labial nerves and vessels.

So one important structure that should be careful about is posterior scrotal or so called posterior labial nerves and vessels because these contents are present only in what? Only in superficial perineal pouch. You can see they are not entering into the D pouch and coming down.

They are going directly into superficial pouch. And one content that you will see only in the deep pouch and not in superficial, that is a nerve called as dorsal nerve of the penis. Dorsal nerve of the penis or so called dorsal nerve of the clitoris. This is one structure that you should remember is present. only in deep perineal pouch rest everything is common so just don't worry whatever the deep artery the dorsal artery of the penis you know artery to the bulb they're all piercing perineal membrane and they are contents of pouches the only nerves and vessels just be bit careful about is a posterior scrotal and labial nerves and vessels and similarly dorsal now of the penis or so called dorsal now of the clitoris which is only in what out deep pouch right so the four important contents in the deep for important contents of superficial pouch plus these structures that we are writing which are specific to the superficial and deep pouch.

If you remember them, I am pretty sure you will be able to tackle any question asked on the perennial pouches here. In fact, before going to the questions, I want to just discuss it on the picture, something that we already saw, the contents which are only in the superficial or only in the deep pouch. Now, just please get oriented to this image here.

I need to enlarge it. it a bit for you. Look here guys, the first thing, this is the pelvic diaphragm, right, that is the highest layer, the pelvic diaphragm. Followed by, this is the superior layer of urogenital diaphragm. Just look at the pointer very carefully, this is the superior layer of urogenital diaphragm.

And this here is the perineal membrane or the inferior layer of urogenital diaphragm, this one. So obviously what pouch is that? That is the deep perineal pouch. And if this is deep perineal pouch, this pouch here below, this one, is what?

Superficial perineal pouch. Now, if you look at this image here, you can see all these nerves and vessels, look at these blood vessels and all they are piercing the perineal membrane, so they are content of both pouches. But as I said, the structures we need to be careful about, nerve is not shown in this image.

nerve of the penis will go through the deep perineal pouch and will go directly on the dorsal aspect of the penis so it is only the content of what pouch? Deep perineal pouch but look at these nerves and vessels can you can you not the nerve at least vessel we can see here these are the posterior scrotal vessels that you see which is coming behind the perineal membrane and then going directly into what pouch? Superficial perineal pouch so that's what we said that posterior scrotal and labial norms and vessels only content of soup superficial pouch, dorsal nerve of the penis is the content of only deep perineal pouch. Let us discuss some questions on the perineum. And these are the standard questions which are usually asked in the exam.

And as I said, it's a very important topic, especially for the Central Institute. So make sure you try out as many questions as possible. as you can on this now see the question says that urogenital diaphragm is made up of the following except and see what I told you that when you see urogenital diaphragm think of what which pouch deep pedal pouch deep deep pendular pouch is between superior layer and inferior layer of urogenital diaphragm.

So, if you think of the deep pendular pouch, that which of these have nothing to do with the deep pendular pouch, you will get the answer. And which of the following structure is not related to the deep pendular pouch, that is the colis fascia. Colis fascia was forming what? It was forming the floor of the superficial pendular pouch.

So, obviously it has nothing to do with the deep pouch or you can say in other words to the urogenital diaphragm. Another question here, it says injury to the male urethra in the bulb of penis, we discussed that, causes the urine to accumulate in all except. Now, we already know that urine can get accumulated in the superficial pendulum.

pouch which is in the option it's there urine can be accumulated in what it can go into the anterior abdominal wall it is there and it can also go into the upper part of the thigh it will not go into the space of resus what a space of reason it's a retro pubic space in front of the bladder just behind pubic symphysis but in front of the urinary bladder that space is called a space of rhesus so you cannot have accumulation of urine in the space of rhesus if the injury is to the urethra that is a space of rhesus is the answer to this question Another question which was asked twice that all are the contents of deep pedal pouch except. See, now we can use that technique here. All are the contents of deep pedal pouch except. Now, what is not the content?

Now, first of all, look at this option, guys. It says dorsal. nerve of the penis.

We said dorsal nerve of the penis is the content of the deep panel pouch. Not in the superficial but it is there in the deep panel pouch. So it cannot be the answer. Sphincter urethrae also called as external urethral sphincter.

Again external urethral sphincter. external urethral sphincter is a content of deep mandible pouch covering the membranous urethra. Bulbourethral gland that is a male gland, male gland is in deep pouch, female gland is superficial pouch. So obviously what is the answer? That is the bulb.

bulb or the root of the penis, bulbous, spongiosus, ischiocavernosus, all those structures are present below the pendular membrane and they are the content of superficial pouch and that is what the question is asking, it is asking about accept. And then we got this another question which says, injury to which of the following deep part of the perineal body can lead to the rectocele, cystocele and the urinary incontinence? Now, which part of the perineal body?

There are so many muscles which are contributing to perineal body. All those bulbous spongiosus and transverse perineal muscle and then we have external sphincter. also to the perineal body.

But he said which component of the perineal body? That which means muscle. Now what was the muscle of pelvic diaphragm which was closest to all the opening, to the urethra, to the vagina, to the rectum and forming all those muscular cells? slings around them and that was what?

Pubococcygeus. So pubococcygeus muscle which forms these modifications called as puborectalis, pubovaginalis, pubourethralis. So it's this muscle, it is this component of the perineal body or you can say it is this component of the pelvic diaphragm injury to which can lead to what?

The rectocele, the cystocele and the urinary incontinence. And one more question which I want to discuss here that is the vaginal sphincter this also is the question asked in the aims that vaginal sphincter is formed by all except well when you see vaginal sphincter is formed by all except look at the bulbous pondous muscle it is also covering the bulb of the vestibule so it is covering forming the bulb of the vestibule so it is forming the part of the vaginal sphincter also pubovaginalis the name suggests pubovaginalis it is obviously the modification of the pubococcygeus muscle and circling the vagina it's also there So, answer is in between external and internal urethral sphincter. Well, there should be no confusion in this because females do not have internal urethral sphincter.

Females do not have internal urethral sphincter. Internal urethral sphincter in male is to prevent the sperm from going back into the bladder. It prevents the retrograde ejaculation. That's why it is there. So during ejaculation, the internal urethral sphincter...

will close and it will allow the sperm only to go down into the spongy urethra but not back into the bladder. So please note that internal urethral sphincter is absent in female and that is obviously not contributing to the part of the vaginal system. sphincter. So that is about the perineal pouches. I hope you understood the boundaries and the contents and how to deal with especially so many nerves and vessels are there.

So only few nerves and vessels that you need to remember in the perineal pouches and I am sure you will be able to do probably every single question on this topic.

Transcript for:Understanding the Perineum and Its Structures

Transcript for:
Understanding the Perineum and Its Structures