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00:00You've probably heard that the gastrointestinal tract within your abdomen is several feet long.
00:04But have you ever wondered how these loops of intestine don't get tangled or bounce out of control when you run, jump or dance?
00:10Fortunately, many of your abdominal organs are held in place by a serous membrane called the peritoneum.
00:17Serous membranes line several body cavities where they secrete lubricating serous fluid to reduce friction from movement of muscles.
00:24And in this tutorial, we're going to talk about the peritoneum and its relation to organs in the abdomen and the pelvis.
00:31So to begin, I'm just going to give you a quick overview.
00:33And we're going to start by distinguishing the two types of peritoneum, which are the visceral peritoneum and the parietal peritoneum,
00:41and describe their interactions with organs.
00:44And we will discuss the borders and structures of the abdomen and pelvis as they relate to the peritoneum.
00:49In the abdomen, we'll look at the peritoneal reflections, the intraperitoneal structures, and the retroperitoneal structures.
00:57And in the pelvis, we're going to be looking at the organs, the muscles, the pouches, and some other structures.
01:04And finally, we'll discuss the clinical significance of the peritoneum.
01:08First, though, let's talk about the structure of the peritoneum.
01:12The peritoneum is a double layer of simple squamous serous tissue called the mesothelium.
01:18And there are two layers of peritoneum, as we mentioned before, and these two layers are known as the parietal peritoneum and the visceral peritoneum.
01:26And these two layers of peritoneum are continuous with one another and have a potential space between them filled with serous fluid.
01:33And this space allows the layers to effortlessly slide over each other, as you can see in our image.
01:38Together, both layers anchor organs and provide support for their movements.
01:42So we're going to look at both of these layers.
01:45And the first of these two layers that we'll look at in a bit more detail is the parietal peritoneum.
01:50This is a serous tissue layer adjacent to the abdominal cavity.
01:53And in this image, we can see it along the boundaries of the abdomen.
01:57The parietal peritoneum is sensitive to pressure.
02:00And pain found here is well localized, unlike pain in the second layer of peritoneum, which is, of course, the visceral peritoneum.
02:07This is also a serous tissue layer, but is in direct contact with the abdominal organs.
02:12We can see it here around the liver, and we can also see a part of the gastrointestinal tract.
02:17The movement of food through the stomach and the intestines causes those organs to stretch,
02:21and the visceral peritoneum is sensitive to this stretching.
02:24However, painful stretching of visceral peritoneum is not very well localized.
02:28So pain signals here that are felt elsewhere in the body are called referred pain.
02:33So now that we've gone over the structure of the peritoneum itself,
02:35let's go over how it is organized in the abdomen.
02:38And peritoneum may or may not completely surround an organ,
02:42so let's take a look at what they might look like.
02:44Organs that are completely surrounded by peritoneum are called intraperitoneal organs.
02:49And most intraperitoneal structures are associated with the gastrointestinal tract,
02:53as this organization allows for both support and movement.
02:56For example, the transverse colon could look something like this.
03:00The lumen that food passes through would be here.
03:02And this is the wall of the colon over here.
03:04And over here we can see the peritoneum passing completely around the colon.
03:09Retroperitoneal organs, on the other hand, are not enclosed within the peritoneal cavity.
03:14Instead, the peritoneum covers retroperitoneal organs only on their anterior surface,
03:19as you can see here.
03:20The organs then have a free surface on the posterior abdominal wall.
03:24And something important to note is that retroperitoneal organs, such as kidneys,
03:28typically exhibit less mobility than intraperitoneal organs,
03:32because their functions do not require expansion or the mixing of contents.
03:36And we're going to cover both intraperitoneal and retroperitoneal organs by their region.
03:41Let's start with the abdominal organs.
03:45The abdomen is bounded by the diaphragm, the pelvic brim,
03:50and the anterior and posterior abdominal walls.
03:53So let's start by looking at the anterior abdominal wall.
03:56This over here is the campus fascia.
03:59And it is one of two layers that make up the superficial fascia of the anterior abdominal wall.
04:04And campus fascia lies directly beneath the skin of the anterior abdomen.
04:08And it's a layer of subcutaneous fatty tissue that varies in thickness from person to person.
04:13Campus fascia is the outermost, almost superficial layer of superficial fascia of the anterior abdomen,
04:19and is continuous with the superficial fascia of the thigh and the datus fascia of the penis.
04:25The deeper layer of superficial fascia of the anterior abdominal wall is known as scarpa's fascia.
04:30And this is made up of membranous fascia that lies deep to the campus fascia we just saw.
04:35And scarpa's fascia is a thin layer of connective tissue that resembles wispy spiderweb-like fibres in humans.
04:41Scarpa's fascia is continuous with the fascia of the urogenital region.
04:45So fluid accumulated in the scrotum or labia majora could ascend the abdominal wall deep to this layer.
04:51And scarpa's fascia is sandwiched between campus fascia and the muscles of the abdominal wall.
04:56And we can see one of these muscles over here, the rectus abdominis muscle.
04:59So the rectus abdominis muscle is the most midline of the anterior abdominal wall muscles,
05:05and it's made up of two columns of muscle on either side of a thick band of dense connective tissue called the linear alba.
05:11The muscle fibres of the rectus abdominis are arranged along the superior-inferior axis,
05:16so that when this muscle contracts, the spine is flexed.
05:19The rectus abdominis also compresses the abdominal cavity,
05:23and in doing so it causes abdominal organs to push against the diaphragm and aids in exhalation.
05:28Let's just take a few minutes to look at the diaphragm right now.
05:32So the diaphragm marks the most superior extent of the abdomen,
05:37and it's comprised of skeletal muscle that inserts on a central tendon near the spine
05:40and decreases intrathoracic pressure when it contracts.
05:44The decreased pressure causes the lungs to expand, resulting in inhalation.
05:48Although it is a muscle situated between the thorax and the abdomen,
05:51the diaphragm receives its innervation from a nerve emerging in the neck, the phrenic nerve.
05:56The subphrenic recess is the space directly inferior to the diaphragm,
06:01and it overlies the liver and spleen, and can be displaced by several inches during inspiration.
06:06And some of the ligaments that stabilize the liver can be found in this area.
06:10One ligament, the falciform ligament, extends inferiorly down the front of the liver
06:14and attaches it to the anterior abdominal wall.
06:17The most distal part of it is called the round ligament of the liver.
06:20Next, let's move on to talk about the reflections of the peritoneum.
06:26So during fetal development, the migration of abdominal organs causes the peritoneum to fold over itself in some areas
06:32and creates peritoneal reflections, which divide the abdomen into two spaces,
06:37the greater sac and the lesser sac.
06:40The lesser sac, also known as the omental bursa, is bounded anteriorly by the lesser omentum,
06:46superiorly by the liver and the diaphragm,
06:48posteriorly by the peritoneum overlying the posterior abdominal wall and its organs,
06:53and inferiorly by the transverse mesocolon greater omentum.
06:57The greater omentum is actually the largest peritoneal reflection,
07:01and it hangs off the greater curvature of the stomach and transverse colon as a layer of fatty peritoneum.
07:07And part of the lesser sac rests between its two layers, as we just saw.
07:12The lesser omentum up here is a smaller peritoneal reflection
07:15that attaches to the lesser curvature of the stomach and the inferior surface of the liver.
07:20As its name suggests, it is usually less substantial than the greater omentum
07:24and lies anterior to the lesser sac here.
07:27The most superior extent of the lesser sac is called the superior recess of the omental bursa,
07:34and as you can see, it lies posterior to the liver, just below the diaphragm.
07:38The lesser sac communicates with the greater sac through the omental foramen,
07:43and it's a small opening posterior to the hepatic portal vein,
07:45the hepatic arteries, and the cystic duct.
07:49The greater sac is the larger part of the peritoneal cavity that houses the intestines,
07:53and it's bounded anteriorly by the anterior abdominal wall,
07:57the liver, the posterior abdominal wall, and the pelvis.
08:01Now let's have a look at some of the structures within the peritoneum.
08:06Remember that the intraperitoneal structures are those that are completely encased by peritoneum?
08:12So this is the stomach.
08:14It's a hollow J-shaped organ that receives food from the esophagus as a bolus.
08:19In this illustration, we can see the stomach from an anterior view,
08:23and the smaller part of the J is called the lesser curvature and is attached to the lesser omentum.
08:27The larger part of the J is called the greater curvature,
08:31and the stomach is made up of three layers of smooth muscle in differing orientations
08:35that churn its contents while glands in its mucosa break down proteins and other macromolecules.
08:42After being mixed and partially digested by the stomach,
08:45the food you eat next moves into the small intestines,
08:48and the first part of your small intestines is called the duodenum.
08:52The duodenum is shaped like a C with four parts,
08:55and these four parts are the first or the superior part,
08:59the descending part,
09:00the horizontal part,
09:02and the ascending part.
09:03In this illustration, the part of the duodenum that you see highlighted in green
09:06is the horizontal part of the duodenum,
09:08or the bottom part of the C.
09:11Now, all of these highlighted structures here are part of the lumen of the small intestines,
09:15and it's very convoluted,
09:17so in this image we can see it in multiple places.
09:19And as food passes through the small intestines,
09:22small microvilli absorb proteins,
09:24fats,
09:25and nutrients that were broken down in the stomach.
09:27And as you can see,
09:28the small intestine is long and folds upon itself,
09:31so it is suspended by a mesentery for support.
09:34So this is the mesentery here,
09:36and besides providing support for the intestine,
09:38the mesentery also transmits the neurovasculature,
09:40supplying the small intestines,
09:42and also some of the large intestine.
09:44And most of the arteries traveling through the mesentery
09:46arise from the artery that we'll look at next.
09:49Which is the superior mesenteric artery.
09:52The superior mesenteric artery is the second unpaired branch of the abdominal aorta,
09:57and it passes inferiorly over the duodenum,
09:59and fans out into a wheel of arteries,
10:01to reach all of the small intestines,
10:02and the first half of the large intestine.
10:05And from this perspective,
10:06we can see some of its smaller branches within the fat of the mesentery.
10:11One branch of the superior mesenteric artery,
10:13the middle colic artery,
10:15travels to the transverse colon,
10:17and we can see it here because the middle colic artery travels in the mid-sagittal plane.
10:22The transverse colon seen here is the second part of the large intestine,
10:25and it extends across the abdomen from the ascending colon at the right colic flexure,
10:30to the descending colon at the left colic flexure.
10:33Because of its proximity to the stomach,
10:36the transverse colon needs to be somewhat mobile,
10:39and it is suspended by the next structure we're going to be looking at,
10:42which is the transverse mesocolon.
10:44And although most of the large intestine is retroperitoneal,
10:47a layer of peritoneum extending from the transverse mesocolon
10:51completely surrounds the transverse colon,
10:53so it is considered an intraperitoneal organ.
10:57So now let's move on to some accessory digestive structures
11:00that we can see in our image here.
11:02So this large solid organ is the liver,
11:05and the liver sits in the superior part of the abdomen,
11:07and detoxifies the blood from your intestines.
11:10It attaches to the anterior abdominal wall by the falciform ligament,
11:14and is usually restricted to the right side of the body,
11:16but in some cases can extend to the left as well.
11:20Blood from the spleen and small and large intestines
11:22reaches the liver through the hepatic portal vein,
11:25and we can only see a small part of it here,
11:27but this vein is fairly large.
11:30It's formed by the merging of the superior mesenteric vein
11:33and the splenic vein.
11:35And about 75% of the blood supply to the liver
11:37passes through the portal vein.
11:40The rest of the blood supply to the liver
11:41comes from the proper hepatic artery, which is over here.
11:45And when it reaches the liver,
11:46the proper hepatic artery splits into two smaller arteries
11:49called the left and right hepatic arteries.
11:53The proper hepatic artery is a continuation of another artery
11:56coming from the celiac trunk.
11:58The celiac trunk arises directly off the abdominal aorta
12:01as the first unpaired branch of the abdominal aorta.
12:04It's a short artery with three main branches
12:07that provide the blood supply to the foregut
12:09and to the accessory digestive organs.
12:12And there are several branches of the celiac trunk,
12:14and these are the left gastric artery,
12:16the common hepatic artery,
12:18and the splenic artery.
12:20From this perspective,
12:21we can only see the common hepatic artery
12:23and the splenic artery,
12:24so we'll just take a quick look at these.
12:27The splenic artery is a large convoluted artery
12:31that courses towards the spleen on the left side of the body.
12:34And it's partially embedded in the pancreas
12:36and provides some of the blood supply to this organ as well.
12:40The pancreas is here,
12:42and it's an endocrine organ that secretes insulin
12:45from the islets of Langerhans
12:46and glucagon from alpha cells.
12:48And together, these hormones maintain
12:50a healthy level of glucose within the blood.
12:53And over here, we have the splenic vein.
12:55And this vein receives blood from the spleen,
12:58the pancreas, and the inferior mesenteric vein.
13:01Rather than running through the pancreas
13:02like the splenic artery,
13:04the splenic vein passes posterior to the pancreas
13:06and is not as convoluted.
13:09Now let's move on to talk about
13:10some of the retroperitoneal structures in the abdomen.
13:13So remember that the retroperitoneal organs
13:16are those with one side covered by peritoneum
13:18and one side against the posterior abdominal wall.
13:21And the first structure we're going to be talking about
13:23that has these characteristics,
13:25is the esophagus.
13:27And you can see this highlighted in green on our image.
13:30It's a hollow structure
13:31and is an organ of the foregut
13:32that transmits food from the pharynx to the stomach.
13:35And it also empties into the stomach
13:37at the esophagogastric junction.
13:40This large blood vessel over here
13:42is the abdominal aorta.
13:43And the aorta is the largest artery in the body.
13:46It arises immediately from the heart
13:48and features many paired and unpaired branches
13:50like the celiac trunk that we saw earlier.
13:54The renal artery is another branch of the aorta.
13:58This paired artery supplies the kidneys
13:59and adrenal glands with oxygenated blood.
14:03This is the accompanying renal vein.
14:05The renal veins drain deoxygenated blood
14:07from the kidneys and adrenal veins
14:10into the inferior vena cava.
14:12The left renal vein also receives blood
14:14from the left gonadal vein,
14:16which drains blood from either the ovaries or the testes.
14:21All right, so now that we've covered the intraperitoneal
14:24and retroperitoneal organs of the abdomen,
14:26let's have a look at the structures in the pelvis.
14:31So pelvic structures are subperitoneal,
14:34which means that they are inferior
14:35to the peritoneum of the abdomen.
14:37And we've been looking at the male pelvis for a little while,
14:39so we're going to cover the shared organs of the pelvis
14:42and the structures of the male reproductive system.
14:46So let's start with the urinary bladder.
14:48This organ is, of course, found in both the male and female pelvis,
14:52but it varies in its location slightly
14:54to compensate for the differing reproductive organs.
14:57So the bladder is lined internally
14:59by a special kind of epithelial cell called urethelium,
15:03and the multiple layers of smooth muscle
15:04making up the wall of the bladder
15:06are collectively called the detrusor muscle.
15:09The bladder receives urine production by the kidneys
15:11and holds it until urination.
15:14When the bladder is full, the detrusor muscle contracts
15:16and urine is expelled through the urethra.
15:19And this action is, of course,
15:20the same for both males and females.
15:23Moving upwards, there is a thin cord of connective tissue
15:26stabilizing the bladder on the anterior abdominal wall,
15:29known as the urecus.
15:30And in humans, it is covered by a layer of parietal peritoneum
15:34called the median umbilical fold.
15:36The urecus is a remnant of the allantois,
15:40which is a structure that drains the fetal urinary bladder.
15:44Our next structure is the prostate.
15:46And the prostate is a male reproductive organ,
15:49so it's obviously not found in the female pelvis.
15:52The prostate produces a milky secretion
15:54that protects sperm from the acidity of the vaginal wall.
15:57And it also contains the first part of the male urethra,
16:00which is known as the prostatic urethra.
16:02Posterior to the urinary bladder and prostate,
16:06in males, lies the rectum,
16:08which is the final part of the large intestines.
16:11And on this image, we're looking at a cross-section
16:12so we can see the transverse rectal folds inside it.
16:16The rectum receives contents from the descending colon
16:19and will hold them until defecation occurs.
16:21And in the female pelvis,
16:23the rectum lies posterior to the uterus
16:25rather than the bladder.
16:26So the position of structures within the pelvic cavity
16:30creates pouches between organs.
16:32And these pouches are named for the organs that border them.
16:35So let's take a look at the pouches found in a male pelvis.
16:40So this is the retropubic space.
16:42And it's found just deep to the pubic bones
16:45and the pubic symphysis.
16:47The retropubic space is usually filled with connective tissue
16:50and is bordered posteriorly by the urinary bladder.
16:52In males, there's another space between the urinary bladder
16:56and the rectum called the rectovesical pouch.
17:00And the word recto refers to the rectum
17:02while the word vesical means bladder.
17:04And the male pelvis only contains one pouch.
17:07In the female pelvis, however,
17:09the presence of a uterus creates two spaces.
17:13So over here we have a female pelvis without peritoneum
17:16covering the muscles or the organs.
17:18And this is the bladder.
17:20And over here is the rectum.
17:22Firstly, we have a vesico-uterine pouch
17:25between the urinary bladder and the uterus.
17:28And over here we have a recto-uterine pouch
17:30between the uterus and the rectum.
17:33All three pouches contain loops of small intestines
17:35and any fluids that may accumulate in the peritoneal cavity.
17:40All right, now let's have a look at some structures
17:42of the male reproductive system.
17:45So let's begin by looking at some structures
17:47associated with the penis.
17:49The penis is a male reproductive organ
17:51and the sponges body in green here
17:53is also known as the corpus spongiosum.
17:56And it's the more ventral body of the penis
17:58and it contains the spongy urethra.
18:01The cavernous bodies, also known as the corpa cavernosa,
18:05are the more dorsal bodies.
18:06And although we can only see one here,
18:08there are two cavernous bodies on either side of a dorsal vein.
18:11And they contain a network of blood vessels
18:13that make up the erectile tissue of the penis.
18:16This small piece of connective tissue
18:19is the suspensory ligament of the penis
18:21and it attaches to the pubic symphysis
18:24as well as the dorsal surface of the penis
18:26to hold the penis close to the pubic bone.
18:30This very small structure is the bulbo urethral gland,
18:34also called cowper's gland.
18:35And it is a paired gland just posterior to the bulb of the penis.
18:39The bulbo urethral glands secrete mucoproteins
18:42that lubricate the urethra during ejaculation.
18:45Homologous gland does exist in females,
18:47although it has a different name.
18:49And this is the greater vestibular gland
18:51and it lubricates the vagina rather than the urethra.
18:55All right, now that we've seen the organs in the pelvis,
18:58let's have a look at some muscles.
19:00The external anal sphinctus surrounds the,
19:03you guessed it, the anus.
19:05It is a band of circular skeletal muscle
19:07that contracts to prevent leaking of contents from the rectum
19:10and it is tonically contracted but relaxes during defecation.
19:14Over here is another circular band of skeletal muscle
19:17known as the external urethral sphincter.
19:20And it surrounds the urethra
19:21and contracts to prevent the leaking of urine.
19:24In males, the urethral sphincter muscles are fairly simple
19:27and only surround the urethra.
19:30However, the presence of the vagina in females
19:32makes the urethral sphincter muscle a bit more complicated.
19:36And in women, it is made up of three parts,
19:38a sphincter urethra muscle around the urethra,
19:41a urethral vaginal muscle that surrounds the urethra and the vagina,
19:45and a compressor urethra muscle that surrounds the anterior urethra
19:49and pushes it against the vagina.
19:52This muscle over here is the bulbospongiosis.
19:56This skeletal muscle originates from a midline raphe
19:59and fans out like a quill of an arrow.
20:01It covers the bulb of the penis
20:02and is thought to contribute to erection.
20:05And finally, let's have a look at a few more connective tissue structures in the pelvis
20:09and then discuss the significance of the peritoneum.
20:12So the pubic symphysis is a fibrocartilaginous joint
20:16between the two pubic bones in the front of the pelvis.
20:19And here you can see the pubic symphysis from an anterior view.
20:22This joint allows for some mobility of the pelvis,
20:25which is particularly important for childbirth.
20:27The rectoprostatic fascia is a thin layer of connective tissue
20:31between the rectum and the prostate,
20:33and it is found just inferior to the rectovesical pouch.
20:37And finally, this over here is the urogenital diaphragm,
20:41and it's a collection of muscles and connective tissue
20:43that prevents the pelvic floor from collapsing.
20:46The external urethral sphincter that we saw earlier
20:48is a part of the urogenital diaphragm,
20:51along with the levator ani muscles,
20:53the perineal fascias,
20:54and several other urogenital muscles.
20:58All right, thanks for sticking with me throughout the tutorial so far.
21:01Before we get to our summary,
21:03let's just have a quick look at some clinical notes
21:05that are relevant to the peritoneum.
21:07So we've included this image of the greater omentum
21:10just to give you another perspective on its location.
21:13And although it is a fold of fatty connective tissue,
21:16the greater omentum plays an active role in immune defense.
21:20The omentum contains milky spots full of lymphoid aggregates
21:23that provide protection by gathering antigens,
21:25pathogens, and particulates from the peritoneal cavity.
21:29And they can even promote inflammation and fibrosis.
21:33Now we've reached the end,
21:34let's quickly go over what we've learned.
21:36So in this tutorial,
21:37we discuss the peritoneum and its relation to organs
21:40in the abdomen and in the pelvis.
21:42First, we distinguish the two types of peritoneum,
21:45and these were the visceral peritoneum,
21:47covering the organs directly on their surface,
21:49and the parietal peritoneum,
21:51adjacent to the abdominal cavity.
21:54Then we described the organization of peritoneum
21:56in relation to the other structures,
21:58intraperitoneal structures that are completely surrounded by peritoneum,
22:01and retroperitoneal structures,
22:03that have a free surface on the posterior abdominal wall.
22:07Then we looked at muscles, organs,
22:08and some other structures in the abdomen and pelvis.
22:11And we started with some components of the anterior abdominal wall,
22:15which included the campus fascia,
22:17scarpa fascia,
22:19and the rectus abdominis.
22:21And some components of the superior boundary of the abdomen.
22:24The diaphragm is the major respiratory muscle,
22:26and the subphrenic recess is a space just inferior to it.
22:31After going over the boundaries of the abdomen,
22:33we named some areas where the peritoneum reflects upon itself
22:36and creates spaces, and these included the greater omentum,
22:40which is a large peritoneal reflection,
22:42hanging off the greater curvature of the stomach,
22:45and the lesser omentum,
22:46which is a smaller peritoneal reflection,
22:48attached to the lesser curvature of the stomach.
22:50These folds create a peritoneal cavity,
22:52separated into two sacs,
22:54the greater sac,
22:55encompassing a larger part of the peritoneal cavity,
22:58and the lesser sac,
22:59near the accessory digestive organs.
23:01And these communicate through the omental foramen,
23:04near the accessory digestive organs,
23:06that communicates through the omental foramen,
23:08posterior to the hepatic portal vein.
23:10Within the peritoneal cavity,
23:12the superior recess of the omental bursa,
23:15represents the most superior part of the lesser sac.
23:18Once we went over the reflections and spaces in the abdomen,
23:21we then began looking at the structures within them,
23:23starting with the intraperitoneal structures.
23:26The stomach is a hollow digestive organ,
23:28that receives food from the esophagus,
23:30and it passes its contents to the duodenum,
23:33which is the first part of the small intestine.
23:35The contents of the duodenum continue into the next part of the small intestine,
23:38that is suspended from the posterior abdominal wall by a mesentery,
23:42and the mesentery transmits neurovasculature to the small intestine,
23:45and some of the large intestine.
23:48The transverse colon is the second part of the large intestine,
23:50and it's suspended by the transverse mesocolon,
23:53to provide it with some mobility.
23:55The pancreas is an endocrine organ,
23:57lying posterior and slightly inferior to the transverse colon,
24:00and the liver is a large organ,
24:03outlateral to the right of both of these.
24:05Before moving on to the pelvis,
24:07we also looked at some retroperitoneal structures,
24:09which include the esophagus,
24:11which is a foregut organ that transmits food from the pharynx to the stomach,
24:15the aorta,
24:16which is the largest artery in the body,
24:17and it features many branches,
24:19including the renal arteries,
24:20that supply the kidneys and the adrenal glands.
24:22The renal arteries are accompanied by renal veins,
24:26draining the same structures.
24:27After going over the structures of the abdomen,
24:29we next moved into the pelvis,
24:31beginning with some organs and spaces that they create.
24:34The urinary bladder,
24:35which contains urine until it is ready to be expelled,
24:38and it's held in place by the urecus,
24:40a remnant of the allantois.
24:42The prostate is a male reproductive organ,
24:44just inferior to the urinary bladder,
24:46and interior to the rectum,
24:48which is the final part of the large intestine.
24:51Within the pelvis, these organs create the retropubic space,
24:54between the pubic bone and the urinary bladder,
24:56and the rectovesical space,
24:58between the urinary bladder and the rectum.
25:00Just inferior to the rectovesical space
25:02is a thin line of fascia called the rectoprostatic fascia.
25:06Then we went over some of the parts of the male reproductive system,
25:09which included the cavernous body of the penis,
25:12which contains erectile tissue,
25:14the spongious body of the penis,
25:16which contains the spongy urethra,
25:18The suspensory ligament holds the penis close to the pubic bones,
25:22and the bulbo-urethral glands secrete a fluid
25:24to neutralise acid in the urethra.
25:27And finally, the bulbo-spongiosis muscle
25:29covers the bulb of the penis.
25:31Next, we looked at some other muscles
25:33and connective tissue structures of the pelvis.
25:35The external anal sphincter
25:37prevents contents from the rectum from leaking,
25:39and the external urethral sphincter
25:41prevents contents from the urinary bladder from leaking.
25:43The pubic symphysis is a fibrocastilaginous joint
25:46between the two pubic bones,
25:48and the urogenital diaphragm
25:50is a collection of muscles and connective tissue
25:52that prevents the pelvic floor from collapsing.
25:55And there we go!
25:56Now we've finished the end of our tutorial.
25:57Thanks for watching.
25:58Happy studying.
25:59See you next time!
26:13Bye!
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