Join Dr. Kushan Kara, a specialist in upper GI surgery at the Royal Derby Hospital, as he provides an insightful session on the essential clinical anatomy of the abdomen. This presentation will focus on the clinically relevant anatomy in surgical practice, discussing the boundaries, key areas, and muscular layers of the abdomen. Dr. Kara will also provide critical information on areas like the inguinal canal, umbilicus related pathologies, abdominal wall access, and muscle fiber directions that are commonly questioned in exams. Join this session to gain a detailed understanding of the nuance of abdominal anatomy, including the areas you may encounter during surgery, such as the thorax anatomy during esophagectomy and areas prone to injury during laparoscopic operations. Moreover, he will cover topics essential to specific surgeries such as incisional hernia repairs, abdominal wall closure, and inguinal hernia operations. This engaging presentation offers opportunities to interrupt and ask questions, ensuring you gain clear and direct answers to your queries.
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Catch up with our first session of our essential clinical anatomy revision series on Abdomen taught by Mr Kushan Nanayakkara  who is a specialist registrar in General Surgery based in East Midlands covering high yield content!

Learning objectives

1. Understand the clinically relevant anatomy of the abdominal wall, specifically the structure and functions of the external and internal oblique muscles and the transversus abdominis. 2. Analyze the clinical implications related to the rectus abdominis and the rectus sheath, including conditions such as divarication of recti and incisional hernia repairs. 3. Develop a mastery of the anatomical features and boundaries of the inguinal canal, and understand its relevance in surgical practice. 4. Identify the different components of the neurovascular plane in the abdominal wall and understand its clinical significance during surgical procedures such as laparoscopic procedures and local anesthesia administration. 5. Understand the importance of Jenkins rule in closing the abdomen after a laparotomy and its clinical application in surgical practice.
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Computer generated transcript

The following transcript was generated automatically from the content and has not been checked or corrected manually.

They. Yeah, brilliant. All right. Uh So my name is Kushan Kara. I'm uh one of the uh specialty doctors in upper gi surgery uh working at the Royal Derby Hospital. So I have been uh invited to uh uh talk to you about uh the clinical essential clinical anatomy related to the abdomen. So it's a vast area. I'll try to do my best. Uh And uh first of all, thank you for the invitation and uh please do interrupt at any point if you have any questions because I won't be able to see the chat option on my uh screen. So uh you can interrupt and uh ask me questions. OK. OK. So, uh I will, I'm gonna start uh with the abdominal wall. So this is uh uh area which is always been asked in your uh exams. Uh I'm going to just highlight the key areas and then uh uh because all of you uh will refer the textbooks and you will uh come across all these, the basic anatomy. I'm gonna talk about only the clinically relevant anatomy uh in surgical practice. So, in terms of boundaries of the anatomy, um you know, so anterior abdominal wall extending from uh the costal margins at the upper end and then the sternum and then it extends downwards. Uh in the lower end, you got the iliac crest and then the pubic symphysis and the pubis on either side, it continues with the posterior abdominal wall and uh then even further paravertebral muscles. So, the important areas uh in terms of the anterior abdominal wall, uh one thing is the inguinal canal, it's been always asked and then the umbilicus related pathologies. And then in, in general, uh the abdominal wall access. So uh mainly uh there are a few layers of muscle, you will see the external oblique, which is the most outer layer. And then we got the internal oblique and the transversus abdominis. Uh I'm not going to talk about uh the insertions and origin, but remember the external oblique muscle, these fiber directions are really important because they always tend to ask questions on these. Uh because it happens uh uh you, you will see those fibers directions and everything during the abdominal entry. So therefore, it is important to uh know about them because then you know which layer of muscles you are dealing with. So the external oblique uh uh muscles, uh the the muscle fibers are running mainly downwards and also towards the medial direction. OK. Uh And you uh see this is external oblique, aponeurosis is mainly uh the large part of it uh where it inserts and in midline, the internal area, sorry, the line elbow on either side, it usually especially the top bit it uh um uh digitate with the certus anterior muscle and also the latissimus dorsi. So those are important, especially uh when somebody discuss you about the thorax, thorax anatomy, uh this is an important element when they get into the uh thoracic entry, uh especially during the esophagectomy, you will encounter all these muscle layers and the important uh uh clinical relevant questions in external oblique muscle is the posterior border of the external abl uh oblique muscle is free and uh there is a small uh area you will see here which is known as a lumbar triangle of pit. It is an area which usually give rise to uh ra hernia called the lumbar hernia. So the margins of the uh the borders of the lumbar triangle is important. You will see anterior, it is a posterior margin of the external lobeli. Then you see the anterior margin of the latissimus dorsi and then the iliac crest. So this is important landmark. Remember that uh famous MCQ in terms of uh external oblique. Once you taken out the uh sorry, internal oblique, you will see the fiber direction completely opposite, it is perpendicular to the uh external oblique, it goes downward and backward direction. OK. And uh um the origin and the insertion, please uh go through it. And uh the important clinical bit is if you look at the, the uh origin of the internal oblique muscle. It originating from the, the uh anterior to third of the iliac crest and also then the uh lateral to third of the inguinal ligament. So these fibers are arching over the uh the inferior margin of the inferior oblique is arching over and then it inserting into the pubic crest. So this is the important uh uh part of the inguinal canal, inguinal roof. So I will uh explain there. But that is the in inferior free border of the internal oblique muscle, transversus abdominis muscle. Again, uh the fibers are running um in the transverse fashion as the name implies. And then the origins and the insertion is documented there. The key factor in this uh muscle is muscle layer is you can see as I demonstrated in this image neurovascular plane in the abdominal uh anterior abdominal wall is in between the transversus abdominis muscle and the internal oblique, both nerves and the arteries and the veins runs in this tissue plane. So this is very important when, when we are giving an uh uh the block uh especially if you are going to do an uh uh inguinal hernia under local anesthesia. This is the area we need to give the anesthesia. OK. It's important. Uh This is the conjoined tendon. So, as I said earlier, the uh the fibers, the origin of the uh internal Loli coming from the lateral to third of the inguinal ligament and the transversus abdomen is coming from the lateral one third. So both of these uh muscles together, they're forming something called the conjoined tendon, which is very important uh especially form in the posterior wall of the inguinal canal. Ok. So this image will show you what does it exactly meaning by the conjoined tendon? Ok. So, the neurovascular plane, as I described earlier, you can see both nerves and also the blood vessels are running in that plane. And always remember these two vessels, the superior epigastric and the inferior epigastric, especially their course. And their anatomy is very important, especially this is one of the commonest blood vessels to get injured during the laparoscopic protein session. So therefore, we need to be accurately aware of these uh blood vessels and it is important in inguinal hernia surgery as well. And uh remember from where it comes and which plane it runs. So that is important. Rectus abdominis again, uh important. So, um which is um a straight muscle, however, a strong and this uh the clinically important bits are there are three tendinous intersections. You can see one at the umbilical level, another at the uh very higher up that is at the sternum level and one usually in between those two, but occasionally there may be some, some uh intersections just below the uh umbilical level, but it is infrequent. Uh and uh these tendinous intersections are only stick to the anterior part of the muscle So, if you see the posterior part of the muscle, you won't be able to see any tendinous intersections. Therefore, the there is a very clear gap between the muscle and the posterior rectus sheath. But anteriorly, you can't separate the rectus sheath with muscle because it is firmly adhered with these intersections. It is important in incisional hernia repairs. When we do, usually we tend to lay down the mesh, uh rectal rectus, that means behind the rectus muscle because there is plenty of space we can go but anterior, it is almost impossible. And um uh the other important uh uh clinical relevance point is the uh what is called the divarication of recti. So, uh what happened is usually in the midline, both rectus muscle fuse together uh at the linear elbow. However, in certain people, because of some reason, uh they are anterior abdominal wall, uh become a bit weaker and the ga will be in a gap appears between this rectus muscle. It is not a true hernia, all abdominal molecule. Uh abdominal wall musculature remains as it is. However, it is a weak point. So therefore, when a patient is lifting their head up, then you will see there is a bulging coming out, however, it is not a true hernia. So, remember that is called the divarication of recti. And uh in terms of the rectus sheath, this is very important uh anterior rectus sheath and the posterior rectus sheath. What are the layers and how does it form? And what are the borders? So these all are important because uh they are especially relevant in uh incisional hernia, repairs and the abdominal wall closure. So in this diagram, you will be able to see uh above umbilicus and below umbilicus, how these muscle layers form the vector sheath? Uh remember the anterior rector sheath above the umbilicus uh formed by the external oblique and the anterior leaf of the internal oblique, posteriorly. It got the posterior leaf of internal oblique and the transversus abdominis muscle. And behind you will see the transilis specia and then the peritoneum. So that is how it is above the umbilicus when it goes below the umbilicus, especially if you look at the area, we are called the uh the uh award line. The posterior recta sheath become absent. So there is no posterior rectus sheath after that. So that is why you can see here all three muscle layers, external oblique, internal and the trans abdominis merge through and form the anterior rector sheath. Posterior sheath is absent. You will see only the transversal is f in the preperitoneal factor and then peritoneal. This is important because when you do an inguinal hernia operation laparoscopically, usually we go in this tissue plane in between the uh transversalis fascia and the internal oblique muscle. So that is very important to know these tissue planes when we go in. Ok. And the other thing is when you close the abdomen. After a laparotomy, the important rule always they will ask what is called the Jenkins rule. This has slightly changed now, which is you need to uh close the abdominal wall incision within a um nonabsorbable suture. And uh it should have a length is approximately four times length of the uh surgical incision. There is another new trial came called the stitch trial and they talk about uh the go with a uh the short distance um uh the in the sutures. However, it's very subjective. Different people practice uh different methods but they still the entin rule is applies. Then uh one of the most important region in the uh anterior abdominal wall is the inguinal canal. So, uh inguinal canal presenting both females and males. Ok. But it is more developed in uh males and the size of the inguinal canal is quite variable uh especially in kids, uh especially newborn, both anterior and posterior. I mean superficial and the deep are almost uh in same line. So there are, there is no canal. But when, when the child grows up, what happen is the with the muscle development, the canal develops and a adult usually it will be somewhere around 3 to 5 centimeters. So it has two ends, deep ring and the uh a superficial ring. This this this clinical important relevant point is always this what is the meaning of the midinguinal point? And what is the meaning of the midpoint of the inguinal ligament. This always ask. OK. So the midinguinal point is the, the midway between the anti perio iiac spine and the pubic synthesis. OK. It is slightly medial to midpoint of the inguinal ligament. So the deep ring of the in uh deep ring of the inguinal canal lies just above the midpoint of the inguinal ligament. Midinguinal point correspond to the femoral artery. So when you uh palpate the femoral artery, you need to go at the midinguinal point. So this is a very famous MCQ always tend to us because we tend to confuse this. And uh then you got the uh superficial lingua ring which is almost overlying the pubic tubercle pubic uh synthesis. And it is uh sort of like a triangular area and it has a very strong lateral edge, lateral edge in the sense, basically towards the uh canal. The edge is very strong, medial, it is a bit weak uh because it is the muscular attachment but lateral, it is very strong formed by aponeurosis contents in males, you will know about all these content. But if I say grossly in males, they got a spermatic cord in female, they got uh the um uh round ligament of round ligament in both genders, you will see the ii in nerve coming through the canal. So that is important in terms of the boundaries. This is important. Always remember anteriorly, what are the structures and then uh posteriorly what are the structures and also uh what are the structures which form in the roof of the canal floor of the canal? And then the medial, you will find something called the lacunar ligament. It is important. These uh questions will be coming um very often in the uh a case. So you may ask to recognize or you may ask to describe the margins. And uh then other uh clinical relevant point is how to recognize the direct and indirect inguinal hernia. Remember, clinically uh dejection of the direct inguinal uh indirect inguinal hernia is quite unreliable. Uh There are studies they identified sensitivities quite less the only way uh to identify or exactly say that this is a direct or indirect is intraoperatively. Here we use a landmark called the inferior epigastric artery. So in this below diagram, you see there is an area called the Hassleback triangle. Here, any hernia coming through this triangle is we called direct hernia. And any hernia coming lateral to that is considered as uh indirect hernias which are originating or which are coming through the deep inguinal ring. Believe me, sometimes it is very difficult to recognize even improperly and there can be sometimes both type of hernias coexist. Then we call it is a pantaloon type hernia. And the other thing is there is another variant of the inguinal hernia in this region called the sliding type hernia. That means when you look at the hernia sac part of it formed by the um tissues itself. For example, it may be sigmoid colon, it may be bladder or it may be any other part which is forming the part of the wall. So therefore, we can't take out the sac. What we do is we reduce the sac completely as an in block version. Ok. And the other important thing is always remember, there is a possibility of damage in the bladder uh in patients with direct inguinal hernias because the bladder may be adhered to the hernia. So they are, it is a very important thing when you uh dissecting the sac, always be worried about the bladder. Sometimes we do insert urinary catheters uh as a measure to identify where the bladder is, that is important femoral canal. So uh this is slightly beyond the inguinal region, but I thought uh I touch this one as well. So the femoral canal uh is again very important because of the femoral hernia. You can see uh this area. This is the what is called the femoral sheath where uh you will find three compartments. Always remember the femoral nerve does not lie within the uh femoral sheath. It always outside the femoral sheath. You got the artery laterally and then you got the vein in the middle compartment. And then you got the femoral canal in medial compartment which often empty or filled with fat or little bit of uh lymphoid tissue called uh called the lymph node of clock. And uh the reason is this the uh it allows enough space uh vein to ex ex uh expand during the uh the uh blood supply. That is why the medial compartment is often empty. But in females because of the childbirth, sometimes there are changes happening in the pelvis which allowing the femoral canal to be larger than normal. So they are, they are at a risk of developing femoral hernia more often than males. OK. However, the other question they ask is, what is the most common type of inguinal hernia? Still, it is in the groin hernia. There is still the inguinal hernia is common among female, but they are femoral hernias is more often compared to males. That is an important thing to differentiate. And uh the margins of the femoral canal is important. You will see this is the uh medial margin, this is the lacunar ligament here anteriorly, you will get the inguinal ligament posteriorly. You will get something called the pectineal ligament and medial, you will get the femoral vein. So therefore, if you are, when you are doing a hernia, if you want to extend to make the opening bigger, you need to extend it medially rather than laterally because the vein can get injured. But at the same time, remember, there are maybe a vessel which is called the accessory obturator artery, which is lying inside of the uh pectineal ligament uh which is presenting about 15% of the patients. So which can get damaged if you are going to blindly uh open up. That is, and again, uh important questions they're gonna ask. Ok. Uh Any questions up to now, shall I proceed? There's no questions in the chat so we can go on. Brilliant. All right. So now I'm gonna uh touch about uh each and every organ in the abdomen. So I'm going to talk about the key effects. So the first thing is the uh stomach. So uh you can see it is the uh widest part of the elementary uh canal. And the capacity of the stomach varies with the patient's age. If it is a child, it is somewhere around 30 MS and then when it become 1500 approximately and adult age, but it can be sometimes 3 L4 L in a very obese patient. OK. And it connects proximately to the uh the abdominal portion of the esophagus at the area called cardia. And this is a relatively very fixed position. So, therefore, uh when you talk about the deceleration injuries during trauma, these fixed points are very important uh uh points which can get damaged. So they are remember those are important. Uh There are few other areas like that. One thing is the uh junction between the D one and the D2 and then the DJ flexure and then Ileocecal junction. So all these areas are fixed to uh uh mobile area. So they are full, they can get they are much more prone to get deceleration injuries. And along the medial wall, you will see the gastrohepatic ligament or we call the lesser omentum. And then on the greater curvature, you will find the greater omentum. So those are important and the clinically relevant bit. One thing is called the uh gastric valves where you can get the uh the rotation of the stomach. Uh There are two types. One thing is called the uh organo A L that is uh the main axis is basically from your uh the geo junction ge to uh your pylori. So the stomach rotates around that. But the other version is called the me uh mesenteroaxial where the axis is from the lesser curvature to greater curvature. So it is mainly your pylori going up, your gej remains same. So that is the sort of uh appearance. And remember there is a hernia type called the um paraesophageal hernia where the that your entire stomach may be inside the chest. So they are much more prone to get vus than a normal person. So those are important and the parts of the stomach. Uh you see this is a fundus. How do you define fundus? Is if you draw a line horizontally from the cardia incisura, the portion above that is fundus, it's, it's a portion always filled with gas and then you get the angularis incisura here. Uh It's a kind of externally appearing notch and in between the area you will find the body of the stomach and then you got the pyloric ru and the pyloric canal. So those two are important and then go and end up with the pylori OK. Relation of the stomach. Remember this is very important because they will ask multiple questions on this uh because it is surgically very relevant area. So you need to know about what are the posterior uh uh relations especially the pancreas. Um And then uh your spleen is locating on the left hand side and then the right kidney is also behind it and the main blood vessels and also the laser sac is behind that. So that is very important to know in terms of blood supply. This is one of the commonest questions they ask you to describe during the uh Y was even in FRC exams, they tend to ask this. So the remember the stomach is a fogo structure. So they are for the blood supply coming from Celiac ais. And as you see, the celiac taxis mainly got uh mainly three blood vessels that is a left gastric and then the splenic and then right uh sorry, the common hepatic. So stomach gets supplied from all three of these branches. Ok. So remember that is very important and stomach is a very forgiving organ. That means even if there is any damage, once you repair it, it heals very fast because it got a very rich blood supply on the other hand, if you have a patient with an stomach cancer and if it's bleeding, it is very difficult to control the bleeding without an operation because you can't embolize because there are multiple branches supplying it. So you can't embolize it, then the option left to is surgery. And other thing is there are many variations in the uh blood supply. I didn't put all the, all the things here. But if you have time, read them, read about them. Those are important. Sometimes the important uh one of the important uh variation is called the posterior gastric artery. Other than this, sometimes you may get a branch coming from the uh splenic artery itself to the, from the back pole. So this is one of the commonest blood vessels can injure during the sleeve gastrectomy when we do the operation because you can't see it. Obviously, it may bleed and then uh it, it may just tear apart and then you can't find it from where it's coming. So the posterior gastric artery, it's very important. And in terms of the venous drainage, uh it goes ultimately into the portal circulation. However, it partly drained directly into portal vein or to uh uh superior centric vein or through the splenic vein. So, the venous drainage is important. And then the other important bit is a lymph node drainage. So, remember the stomach again, got reach lymphatic network. And uh I'm not going to detail in uh I'm not going to give you the great detail, but there are 16 lymph nodes patient related to uh stomach. OK. And uh the Gr and a Japanese classification, these are very important in terms of the uh gastric resections, depending on the type of lymph nodes we are taking, we do sort of like have ad one lymphadenectomy, D2, lymphadenectomy or A D3 lymphadenectomy, depending on the number of stations. We are going the D 1 to D3, your resection radical. It is getting worse and worse. For example, D one, you are just going to take the lymph node around the stomach that is like station one to station six up to station 10. You consider it as a D2 D3 is very aggressive. You are going to take all the lymph nodes. It's only performed in certain parts of the world in UK. It is something called a modified D2. That means even we don't take the D2 completely, we take only few lymph nodes around. OK. So we need to balance the survival benefit versus the uh the uh complications associated. That is why we end up in that type of situation. But remember there are 16 lymph node stations uh in terms of uh a lymphatic drainage innervation again, important. So uh anterior vagus, which is usually the left vagus become the anterior and the right become the posterior anterior got extensive lymphatic network, uh sorry, the neural network. And you can see uh the anterior vagus supplying to the liver. And also it supplies the gallbladder and also it supplies the pylori. So this was basically uh one of the famous questions earlier because we used to perform something called a highly selective vagotomy and selective vagotomy to control the gastric ulcers. But we no longer use them because of the PPI S are really good. So therefore, they are more effective than these operations. But uh you need to know about what is anterior vagus, where does it supply? And what is roughly the posterior vagus and they are caused from the th uh the thorax downwards. So this is important bit. OK. Any questions on uh stomach? OK. So I'll proceed. So the duodenum again uh important. Um It's a kind of a ac shaped structure even though it is a PC shape, it is three dimensionally, it has a complex shape. So uh read about the directions that is important, especially when you are going to do an endoscopy, especially gastroscopy when you're going to negotiate from D one, the first part of the duodenum to D2. Um there is an acute angle. So you need to uh go in that direction. OK. So that is very important. And uh this is the uh the most uh uh shortest uh most predictable segment of the small bowel. And part of it is retroperitoneal and part of this is intraperitoneal. OK. So, uh this is important and uh the location roughly where it located and within the C loop, there is the head of and head down there. Uh uncinate process of the pancreas located. And the approximate length of the uh duodenum is sometimes been questioned. I'm not sure still they are going to ask those things. But remember the shortest segment is the D four, which is about 2.5 centimeters in length. And the relations again, very important, uh especially you need to know about what is the relationship of the uh superior eccentric artery and the superior eccentric vein. And this is an important element when you talk about something called the mel rotation where uh you will find the uh the DJ flexure, right usually lies on the left hand side of the vertebral column. It completely goes to the other way. So your D DJ flexion will like on the right side. OK. And we, and during a CT scan, we will be able to find out the relation in the uh the, the relation to the SM and S MV. That is an important landmark to identify the malrotation. And again, uh the right kidney and the renal pelvis lie behind. And also, um if you're a color, if you see the colorectal operation, when we mobilize the right side of the colon, uh duodenum is one of the possible structures to get damaged because uh when you lift up the colon, usually the duodenum also comes with it. So, but it is very important to know OK. And the blood supply, again, one of the most important aspects which we encounter for, one of the causes for the upper gi bleeding is the peptic ulcers. So, if you have an uh uh the, the commonest areas, uh where you can get the peptic ulcer is the D one, uh, very infrequently, it goes to D2 and D 3D 4 are very, very rare. If it is also in the 3d 3d 4 region, you need to investigate for uh special courses like whether you got an uh uh uh what is called the uh gastrin secreting tumors because it is very, very infrequent to get uh ulcers there. The most common area is the D one and the laser curvature of the stomach. So, if you have an ulcer, which is eroding through the anterior wall of the duodenum, then the patient can develop peritonitis. But if it is eroding towards the posterior wall, that means you are at peritoneum, the patient is not septic. However, it can erode into this special structure here, which is known as the gastroduodenal artery. The gastroduodenal artery is usually coming from uh the common hepatic artery. It divides into gastroduodenal and then you get the common, the hepatic artery proper. So, this gastroduodenal artery is a structure which can get damaged uh and causing torrential bleeding if it is uh invading the posterior wall, that's an important landmark. However, it can be, it is uh it, it is possible to embolize these vessels. So therefore, you can control the bleeding with I er team interventional radiology. Otherwise, uh remember about the blood supply, uh pancreaticoduodenal artery, superior and inferior and uh from where it originating. So all these things are important in terms of the small bubble. So this uh graph basically, I try to, I try to summarize the key points here. When you do an operation, sometimes you may struggle to find out whether this is this a Jejunum or is this ileum. So there are things that you will note. One thing is uh approximately the proximal two third of the small bubble uh made up of uh Jegen. And the distal 3350 is made up of ilium. And the last 30 centimeters from the ileocecal junction, we call it is terminal ilium. This has a very discrete function. So read about it, especially physiologically, those are very important. And the Jejunum is usually very thick cold and it is wider in diameter compared to ilium. And if you feel it uh deum, you can feel it is very thick cold and it is more darker in color because it's uh it's having a very rich blood supply compared to ilium. Ilium is slightly pale in color. And in a radiograph, you may see the plica circularis are more deeper and more frequent in jejunum compared to ilium. OK. And uh especially terminal ilium, usually it is almost flat. And then in terms of lymphoid tissue. The Jegen have a very uh limited lymphoid tissue. So especially the proximal part is completely absent. But towards the distal segment, there is some amount. But in compared to ilium, it is almost negligible ilium got very frequent and extensive lymphatic tissue which is palpable. So you can feel the lymphoid and these are the sometimes the areas which can lead to intussusception. So the ileal interceptions are more common than digit in terms of blood supply, I will describe it later. But remember both of these structures are midgut structures. So they are for origination, blood supply coming from superior centric artery and the location wise you know about it. So if you look at this diagram, you will see the blood supply, the jejunum basically get only about like 5 to 10 arterial branches and the way how it is. So the the right hand side diagrams, you see uh there are only one or two arterial arcades and then straight away this enter into the bowel. But if you look at within the bowel, it has numerous branches. So therefore, it is very dense in vascularity because it is the most important portion for the absorption of nutritions. In terms of the, if you compare with that one with the ilium, you can see the blood supply is less numerous, but there are a lot of arch. So we call this multiple tiers. Uh and therefore there is a lot of overlap. However, uh there's a lot of overlap but it is less dense blood supply and it get multiple branches. So if you look at this lower segment, there are numerous smaller branches coming from the to supply the ileum. So that is very important to differentiate the blood supply of these two. The other important thing, clinically relevant thing I want to talk about is a mis diverticulum. This is uh a remnant of the proximal part of the vital intestinal tract. And um in most of the patients, this is get completely obliterated, but in about 2 to 3% of the people, um either there is a rule, we call it as like a rule of two. but it is not a, it's not very accurate. Uh According to the data, they're saying it is about 3% of the population and it is usually locating, we call it is 2 ft, but it is uh roughly between 50 to 100 centimeters from the ileocecal valve, usually on the centric border. And uh the length can be variable and uh the the nature of the diverticulum can be variable. It could be very narrow, like appendix or it could be very broad. So there are sometimes you tend to miss that. Ok. But average length is roughly around five centimeters and the tip of the diverticulum is usually free. However, in certain people, there may be an attachment to the umbilicus, we call it is there is a fibrous band. This fibrous band is sometimes given a lot of problems because it acting as a point where the small bowel can go wrap around it and give rise to world virus. So sometimes patients end up in small bowel obstruction, a the mis diverticula mucosa. Uh the the usually it is normal ileal mucosa but occasionally there is something called the heterotropic mucosa. You should know about the pathology wise. What is the meaning of the uh the metaplasia? And also what is the meaning of heterotropia? The heterotropic mucosa means it's a normal mucosa in an abnormal location. So you will see the gastric mucosa in this abnormal location, pancreatic tissue or sometimes colonic tissue. Remember this is one of the commonest cause for occult small bowel bleeding where you can't find. In that case, you have to do something called the red cell scans then or what is called the M scan. Uh They give a radioisotope and do a scan. They can identify from where the bleeding comes from. OK. And uh then uh the other important thing is how do you operate? It is not really much important for you guys, but remember roughly either you can take the diverticulum out completely, you can fire a circular stapler across this. Um or else you have to do a wedge resection, especially base of the uh mis diverticulum is wide. Then you need to take a wedge out because you can see sometimes there may be some gastric tissue here and there. Ok. And if it is completely necro or damaged, so then you have to take a piece of small bowel out with it and then you can do an end to end anastomosis. The, the important thing I want to highlight is the Michael's diverticulum sharing the same innovation as appendix. So they are for the patients, symptoms are more or less same. Ok. Therefore, if you do an appendicectomy, if you uh can't find the uh the course for the abdominal pain, if the appendix is absolutely normal, then always, always look for uh Michael's diverticulum because it could be there. So that is a part of your operation. OK. So then we are coming uh next to the part called the appendix. So I will quickly go through. But remember this is very important. Uh It's a tubular structure with variable length, OK. And almost always the base of the appendix is quite fixed. So it is at the mcburney's point, but the tip can have a variable position. The most common areas are the retrocecal and uh uh but there are some other infrequent areas like pelvic, preileal, postileal. I didn't put percentages because it's quite variable in literature, but try to identify in terms of frequency from the most frequent to least frequency. OK. And it got a entry uh at its free age, you will see the appendicular artery which is a bra branch of the ileocolic artery, which is important when you do an appendicectomy. OK. And uh the base of the appendix, sometimes if you can't find the, the appendix is what you need to do is you trace the uh tia Coli of the cecum. And then at the point where all these tias are merging, that is the base of the appendix. That is how you recognize it. It usually locating uh just medial as well as posterior to the terminal ilium incision. But when you, the inflammation of the appendix happens, sometimes you can't find all these areas because they are all stick together. But the good landmark is to follow the tia. And so this is the appendix. And uh I saw a couple of questions on uh the types of incision and the layers when you go through. So this is the incision on the right. Uh the left hand is called the mac uh the incision. And the, the right hand side is called the lance incision. OK. So uh the important thing is you need to identify we are the base of the appendix and you need to center your incision uh at this point. OK. And try to identify the layers. So in this one, I highlighted, you go through the skin, the fascia cappas and up to the external oblique. Then you see the direction of the fibers, you split the external oblique aponeurosis, uh open up, then you find the internal oblique, the opposite direction fibers. Then you need to use the scissors and split it. You are not going to cut split tonally. Then you find the transversus abdominis split again, then you find the transfacial transversalis and the peritoneum. So these layers remember they will be asking the exam. OK. So those are important especially with the direction of the fibers in terms of a large intestine. Uh so it is a long tubular structure which usually lies on the periphery of the abdomen. From ileocecal val to uh anus approximately it is about 1.5 m in length. However, can be variable. A lot of anatomical variations, partly intraperitoneal, partly retroperitoneal. This the length of the intraperitoneal or the retroperitoneal can be quite uh variable, especially in certain people. Cum is completely retroperitoneum, some people, it is completely intraperitoneum. So it could be variable and usually the wider segment is a cecum and the narrowest segment segment is a sigmoid colon. So that is why remember the sigmoid colon is much more higher risk to develop diverticula because when it is narrow, the pressure inside the colon is high. So they are much more prone to get diverticula. And uh then uh you can see these uh small uh the fatty tissue coming from the colon that is called the uh epiploic appendages. So these are uh pretty common along the colon. However, it is absenting cecum recommending the appendix. So that is important externally, you will see the host rations, uh the host rations happens because of the uh the longitudinal muscle layer is not complete in the colon. It arranging in three layers, the tia. So that is why these tia are giving rise to host patients. These are important. And the other component important factor is the blood supply because the colon sharing mid gut and hind gut origin up to two third of the transverse colon, the right two third and the left one third junction, it is mid gut. So you're getting blood supply from the sma, from the lateral one third of the transverse colon upward, it receiving blood supply from the inferior centric artery. So that is important because it is high gut. And this is again important. Uh The large intestine remember there can be lots of variations. This is the commonest uh the anatomy possibility, but there can be a lot of variations you can see mainly in the right side. You will get the e colic uh and then it gives rise to the right colic and then the terminal bit uh anterior cecal, posterior cecal like that. But the important one is a middle colic, middle colic is basically uh giving a lot of branches right and left and it giving trans colon and then left side, you get the left colic and the uh sigmoid arteries and uh rectal branches. The important thing is there are, there is a blood vessel runs all around here. Para we call it is a marginal artery. That is why there is an rich anastomosis. Sometimes one of your branches get occluded, but the colon can survive because there is an anastomosis between. Ok. So uh that is why we talk about the intestinal ischemia, especially we talk about the thrombosis and the uh embolism. Uh When you talk about the thrombosis, thrombosis happens often at the uh origin of the blood vessel from the aorta, especially commonly in the S MA. If it involves with occlusion, huge amount of blood supply will be lost. For example, if you see in this diagram, if it occluded here, the middle colic will be cut off and then the terminal branches of the S MA. So massive amount of bowel will necro but if it is an embolism, usually it's stuck few centimeters below uh the uh ma origin. So there are four, there isn't a much chance that less power involvement. So the outcome is better. So remember, outcome is better with embolism than thrombosis. OK. Again, venous drainage, remember especially the sema and the I MA branches. Uh we are to identify the I MA is again, very important, especially uh it is very next to uh DJ flexure. It is one of the most consistent landmarks where you can identify I MA go and join with the splenic vein and then it drains into the portal vein. OK? Lymphatic drainage. Again, it follows the blood vessels. That is what you need to remember. And there are different tiers just read about it. That's important, especially in terms of colorectal cancers. And this, this slide eye especially put because of the Hartman's procedure. Uh because uh the relation of the gonadal vessels, relation of the ureter and then the common IIAC and then the sacral pro. So all these structures are important because when you mobilize the sigmoid colon, the ureter is at risk of getting damage. So, therefore, you need to know about this anatomy really well. Ok. Ok. So um I got about 10 minutes more. So I'll uh go through the uh liver. Do you have any, any any questions up to? Now, we have one question. Uh Yeah. Is the minimally invasive laparoscopic intercorporeal rectus, a neuroplasty, your preferred abdominal wall reconstruction operation for no tension, ventral hernia repair for medium midline defects of under 10 centimeters width to lessen, postoperative pain, bulging and recurrence. And when would other endoscopic component separation techniques be superior for closing the hernial defects? So the um incisional hernia is sort of like a very big area, very massive area. And if you talk about the abdominal reconstruction, I mean, it's a separate topic to talk about. But remember uh we try to uh it's it's all depending on intraperit. So usually we do is we preoperatively assess the patient, uh especially we do the CT scan and then we uh see the content and uh we have to look for the strength of the muscle. And we call something called the loss of domain, the amount outside the incisional hernia. We have to consider all these factors and then we decide what is the best option for this patient. Sometimes uh we can do a straightforward incisional hernia repair without component separation. Sometimes we have to do a uh posterior uh component separation or sometimes we do an anterior component separation. There are different techniques called ta likewise. Or else you can go something like a progressive pneumoperitoneum to get some space in the abdomen and then do the hernia repair. So likewise, there are a variety of things, Botox injection. So I think it's uh sort of like uh they want to ask you to that extent. But remember uh the the key layers are very important, especially in terms of the anatomy, rectus, sheath, anatomy uh is very, very important. Uh especially we are the neurovascular bundle list. And um uh how can you uh expose those? Those are the important things they're gonna ask? OK. Any other questions? Not at this moment? Fine. OK. So I'll uh quickly go through the liver. Uh So again, as you describe, it is the size of the liver varies with the age gender and also the body size of the person. Uh So usually the liver is growing gradually until age of 18 and then it become a plateau. And then after few years later, then the liver start to get strain gradually in a child. If you look at the the body weight and the liver weight, it is about 5%. But when you become an adult, it is about 2%. So these are important things can be asked in the MCQ. Ok. Gross anatomical division, liver got right lobe, left lobe, cordate lobe and the uh quadrate lobe, the cordate lobe is the one which is posterior. That means it is locating a bit higher up and the cord uh sorry, the quadrate lobe is the one which is next to gallbladder. It is a bit lower down. OK. However, this does not represent the liver accurately. You have the liver can be divided into a eight segments. Uh We call the coronate classification depending on the distribution of the blood vessels. You can see here the hepatic veins, right hepatic vein, middle hepatic vein and the left hepatic vein that is splitting all these into uh different areas. So remember there is segment one is basically the one which is in the center and then you have the 234 and then 5678. So you you have to remember uh in a way, but this is more complex than we can see in this two dimensional image. When you go to 3D, it is very difficult, but this is very important in liver transplantation. And the other thing the the hepatic artery got and the blood supply to the liver comes from two sources. Portal vein, which is about 70% and another 30% coming from the hepatic artery. So the hepatic artery, you can see it gives multiple branches. Usually the hepatic artery portal vein and the uh bile duct system. Um following the same pattern. Hepatic vein distribution is different. Ok. So there are many variations. Sometimes they may ask what is the most common variation of the liver blood supply? Remember, these are they replace right hepatic artery, replace left hepatic artery. So likewise, there are many variations. OK. So uh I don't have time to talk about, but these are important points to remember this slide again. Very important. You will see the relationship in the uh we call the pringle maneuver. This is very important, the free edge of the hepatoduodenal ligament. And you can apply the pressure through the through the foramen of wind slope where you apply the uh the uh pressure to control the blood supply to the liver in especially in a liver trauma or in surgery. But remember this, uh the real anatomy is very important, the relationship of your common bile up to the hepatic artery and to the portal vein. So this is very important and commonly asked question. OK. So those are important. Again, you can see that I'm just giving a little bit of anatomy about the hepatic vein. Remember the right hepatic vein, which is the largest and the longest. Uh it drains almost right lobe, but you can see the middle and the left hepatic uh uh veins are usually joined together. They're forming a common trunk and drains into the uh IV. But right hepatic vein usually drains straight away. There can be some abnormal blood vessels which is called the minor veins. Uh sometimes a segment one complete drains directly into the IVC if it is. So if we call the Bahari syndrome where there is a hepatic vein, thrombosis happens, then the this uh uh minor veins can get the compensate. So it become the liver, the segment one become hypertrophic and function as normal. And this is very important in donor transplantation, liver donors, these minor blood vessels are very important. So therefore, it is it is important to know there are minor veins, you don't need to know specifically. But remember the segment one can drain separately into the IVC. OK. And the biliary system again, you can see it's very similar to the, the the supply as the uh hepatic artery. And uh they appreciate where the Hartmann's pouch is. And then the spiral valves, those are important. And then the Hepatocystic triangle and the color triangle. So it's always confusing. So this is very important to know where the margins are and where are the boundaries are. So that is important. Again, pancreas go through it and try to find out what are the components of the pancreas. They're very important to know about the relations especially relation to the common bile duct and relation to the and the portal vein. This is very relevant when they're going to do a wh operation, pancreatic cancer, depending on the involvement of these blood vessels. Extent of the the operability changes, it's become resectable only if these blood vessels are partially or completely, not involved. So those are important things to remember. And the other thing is you can see the top end of the pancreas, you can see the splenic artery. This is important when you got a severe pancreatitis. Sometimes there can be pseudoaneurysms from in the splenic artery which can bleed horrendous bleeding. It can lead to sometimes condition called the hemosuccus pancreaticus where you can get upper gi or lower gi bleeding where this he the pseudoaneurysm broke into the uh pa pa uh pancreas and it drains through the sphincter of odi into the uh duodenum. So those are important and the blood supply and the venous drainage just uh uh go through it. And this is the other important thing. You need to know the pancreatic duct variation. You can see the normal variation reme the you, you guys may remember the uh embryology during development. So usually the accessory pancreatic duct get very tiny and the main duct become the prominent. So this anatomy only present in 50% of the patients. This variation where there is no connection between the um uh the accessory and the main duct presenting about 10% and two separate ducts uh present in about 5%. There isn't a difference here. You can see here, there is no connection only. But the main uh gland drains through the major major papilla. But here, main main, the, the majority of the gland drains through the minor papilla. So these two, the B and the C together we call it is pancreatic, pancreatic pancreatic divisum. So it is in about 15% of the patients. It is one of the course for pancreatitis. So that is very important to know in terms of the spleen. So uh you can, you need to know what are the relationship of the spleen and what are the ligaments of the spleen? This is very famous question. You will see the attachment line or renal ligament and then you will get the uh the short gastric vessels in the uh gastro asplenic ligament and then you can have a splen um uh with the diaphragm and also then with the colon. So these are important uh when we are doing the splenectomy and remember the blood supply and the tail of the pancreas line lies within the spleen, uh the line or renal ligament. So that is very important. When you do a, a splenectomy, you need to put a clamp here. So then when you put the clamp, it is at a risk of getting pancreatic tail can get damaged. So that is important to know. And the other clinical important things are splenicus you need to know what are the location of the splenicus and uh the splenectomy, as I said, and the ops they always tend to ask about uh this uh overwhelming postsplenectomy infection. Try to identify, understand the vaccination schedule. They tend to ask this over and over again and then the splenic trauma. All right. So, uh sorry, I had to rush to the last bit. Uh But uh I hope uh OK, so, uh any questions, there are not any que further questions in the chat. Uh I've missed a little bit from the last question, which was a query. Please educate us about the Morales's con classification. I'm not sure about that. I don't know about that. Actually, it may be something related to um the uh abdominal wall reconstruction. So it's a kind of like a very vast field. II II don't have much exposure about the abdominal wall reconstruction. So we do certain incisional hernia repairs and we do called the posterior tar release. That is a transverse abdominis muscle release. But other than that, we are not a specialist unit who is doing the uh uh abdominal wall reconstruction. And uh uh so they are uh uh I mean, only very limited centers in UK doing the abdominal wall reconstruction because of its highly specialized. It is uh it is not easy to do those cases in each and every hospital. We have someone asking about your email because they were unable to see the last slide. Yeah, so I can uh put my email uh here. Mm. Uh We have, what clinical anatomy book would you recommend, please? Uh I mean, it, it's your choice actually the whatever the book that you were comfortable or you were studying during the M BBS just try to build up. Uh But I think uh uh in terms of uh II, prefer, II basically used to read something uh some the book called The Gray Anatomy. So because the one reason is it was very extensively talk about the anatomy, especially the variations and all, but it takes a lot of time. So you don't need to spend a lot of time on that. But what you can do is you read the questions and if you can't find the answers, then you can refer that book because most of the answers you will be able to find through that book. But if you write, try to read from cover to cover, that takes long time and you won't be able to remember. But it's good for uh to understand the difficult concepts. And also, especially if they talk about really nicely about the anatomical variations. Uh that is really good. But otherwise, uh I mean, uh you guys will be familiar with uh Ellis and then last, so those are the books uh which has been commonly used. There are no further questions. So thank you very much for coming today and delivering an excellent session. If everyone can fill the feedback uh form that will go out, it's very helpful for us to improve and it'll, you'll receive your certificate after doing so. Once again. Thank you and hope everyone has a good evening. Ok. Thank you for invitation. And uh I hope basically you learn something. Thank you. Thank you.