 So, this is a demonstration, a detailed demonstration of the structures which are located in the entire anterior abdominal wall. So, let us start with the most superficial structure after we have reflected the skin. This is the superficial fascia. The abdominal wall has got two layers, the outer fatty layer most of which has been removed and that is called the camper's fascia. And just deep to that is this layer which we can see. This is the membranous scarpus fascia which also we have reflected. What we see in front of this is the abdominal wall with the fascia removed. So, let us start off with the three flat muscles of the abdomen. The first muscle that we see here, this is the external oblique muscle. This is on the right side of the cadabra. We have done a detailed dissection on the right side and we can see that the direction of fibers are running down and medially like this. It is like as if the hands are in the pocket. So, this is the external oblique muscle. It takes origin from the fifth to the twelfth ribs and it also takes origin from the outer limb of the iliac crest. And the fibers medially they form part of the rectus sheet which I am going to describe a little later and inferiorly the fibers they form the eponeurosis forms this structure here. This is a very important structure it is called the incvinal ligament. It extends from the anterior superior iliac spine and ends at the pubic tubercle. So this is the extent of the external oblique eponeurosis. So the proximal portion of the muscle is fleshy and the medial and the inferior portion is eponeurotic as we can see very clearly here. Now we have split open the external oblique muscle and I am reflecting it now. And once I reflect it we can see much more clearly the incvinal ligament. And this is my finger is running along the incvinal ligament which is the inferior free upturned margin of the eponeurosis of the external oblique. And this is the anterior superior iliac spine here and this is the pubic tubercle here. So this is the full extent of the incvinal ligament. Having reflected the external oblique both laterally and medially we see the next muscle and this is the internal oblique muscle. The internal oblique muscle has got fibres which are in the opposite direction. The fibres are running upwards and medially. So this is like as if the patient has got his hands crossed and over to the opposite side of the chest like that. So this is however if you look further lower down we notice that the fibres are not directed upward and medially they are instead directed downwards and medially. But the bulk of the fibres are directed upwards and medially. So this is the internal oblique muscle. This one takes origin from the middle lip of the iliac crest and it also takes origin from the lateral half of the incvinal ligament. Therefore it also forms part of the anterior wall of the incvinal canal which I have mentioned just now. And the fibres then go medially and they also help to form the rectus sheath which I have described and they get inserted onto also the 10th and 11th and 12th ribs. So this is the internal oblique. Now I am going to reflect the internal oblique. I am reflecting the medial half of the internal oblique and I am reflecting the lateral half of the internal oblique. And once we reflect it we see the third muscle of the abdomen and this is the transversus abdominis. And this also we notice the fibres are running transversely that is what is called transverse abdominis. Just like the other two muscles, medially they become aponeurotic. The point to be noted here is that we notice numerous nerves running along with arteries. Neurovascular structures are running. This is the neurovascular plane that is the plane between the second layer of muscle internally oblique and the third layer of muscle the transversus abdominis. The transversus abdominis also takes origin from the inner lip of the iliac crest and it also takes origin from the lower ribs and it also takes origin from the lateral one fourth of the inguinal ligament and the fibres then converge medially and they become aponeurotic and they also helps to form the rectus sheath which I am going to describe just now. So this is the these are the three flat muscles. What are the functions of these three flat muscles of the abdomen? They help to maintain the interabdominal pressure. They maintain the tone and they help to contain the abdominal contents in place. And whenever we do any maneuver to increase the interabdominal pressure like for example coughing, sneezing or straining at maturation or defecation it is these muscles which are responsible. And the nerve supply of these muscles is the thoracoabdominal nerves and we can see the thoracoabdominal nerves here. We can see some of them. As I told you they run in the neurovascular plane. The thoracoabdominal nerves are T7 to 11 and the subcostal nerve T12 which run from the intercostal and the abdominal supply the abdomen. So therefore above the umbilicus which is here is T789 at the level of the umbilicus is T10 and below the umbilicus till the inguinal ligament is T11 and 12 and below that of course is the inguinal. So this is the quick nerve supply and the function of the flat muscles of the abdomen. Finally, a few quick words about some abdominal incisions that are done in surgery. Nowadays most of the elective surgeries that are performed are by laparoscopy. However, there are some indications when we do have to do open up the abdomen which is known as laparotomy and that is when there is a failed laparoscopic surgery or when there is a penetrating your open blood trauma with internal injury or when there is cancer or when there is generalized peritonitis these are some of the situations when we do have to open up the abdomen. So what are the incisions that we make? The quickest is the midline incision through the linealba it can be super umbilical inframilical. This gives very rapid approach. The thing about incision in the linealba is that when we closing it because the linealba is relatively abascular we have to close it with non-absorbable material. I personally prefer nylon loop and that gives a very strong repair. I have seen people repairing with absorbable material and the patient comes back with an incision hernia one year later. Another incision is a paramedic incision that is just like we have done here split open the anterior rectus sheath retract the rectus abdominis laterally because the nerves are coming from the lateral aspect. So we do not rectate immediately we retract them laterally and then we split the posterior rectus sheath and we can enter the abdomen. So this is the paramedic incision again right left super umbilical inframilical. Some places some surgeons prefer an incision by the side of the rectus abdominis and this line which we said was a c-lineal seminary and that incision which is not very commonly used is referred to as the battles pararectal incision. So this is another incision that is used in children when we are doing a surgery for the abdomen and do a laparotomy we do not use vertical incisions we use super umbilical horizontal incision because it is it gives much better access and it is much easier to repair and when we repair we repair all the three layers of the abdominal muscles together. Few special incisions are also used especially if there is a failed laparoscopy and one of them is an incision parallel to the right subcostal margin and that is known as a cocker's incision which is used for the right lobe of the liver and especially for the gallbladder. We have an incision for appendix and that incision is referred to as McBernie's grid iron incision and that is done in the case of appendicectomy when we cannot do it by laparoscopy procedure. The landmarks for that incision is if this is the anterior superior spine and this is the umbilicus we draw a line that is called the spinal umbilical line and we take the junction between the lateral one third and the medial two thirds so approximately at this location we cut the external oblique and then we do not cut the rest of the muscle we just split the fibers the next muscle that we see here is the internal oblique and what we have done here is we have actually split it and then what we see underneath will be the transverse abdominis then we split that and we can enter and we reach the cecum and appendix this incision is referred to as the McBernie's grid iron incision and last but not the least in females when we have to do a caesarean section we do an incision parallel to the just above the pubic bone here like this and we incise and then we separate the two rectus muscles and then we split open the fascia transversalis and the pediatral peritoneum and we can reach the pelvis so this incision is not visible because it is below the line of the bikini that's why in common parlance it is referred to as a bikini incision but technically it is referred to as the fannin steel incision or the suprapubic incision so these are some of the incisions that we do one more thing I wanted to mention is something called incisional hernias and other hernias I already mentioned about the incisional hernia in the region of the linear alba if it is not repaired properly incisional hernia can occur anywhere if it is not been repaired properly and there's a muscle weakness or the nerve has been cut we can have hernia coming out through the umbilicus and that is not very uncommon in children that is the umbilical hernia in 93% of cases the umbilical hernia children closes by one year of age so it does not require any surgery only 7% of them require surgery and that has to be repaired in adults the hernia does not come out through the umbilicus it comes by the side of the umbilicus usually above the umbilicus just above it is known as parambilical hernia this difference is very important and umbilical hernia is common in children parambilical hernia occurs in adults in umbilical hernia the her umbilicus is at the apex of the hernia sag in parambilical hernia the umbilicus is at the wall of the umbilical sag so that occurs only in parambilical occurs only in adults in many thin world individuals we can see a gap between the superior rectus above the umbilicus and especially when you lift up the head from the bed without using their hands you'll see a bulge that is referred to as a dive adication of recti which is usually common commonly seen in the upper part of the abdomen so these are some of the institutional and other ventral hernias that we can get in the abdominal wall depending on what situation it is so that is all for now thank you very much for watching if you have any questions or comments please put them in the comment section below dr. Sanjay Sanyas signing out have a nice day