 to be an exhaustive dissection demonstration of the abdominal thoracic diaphragm. The first thing to understand is that this whole thing is the diaphragm and this was covered by a thick layer of fascia and that is the endo-abdominal fascia. And on top of that was a layer of parietal peritoneum and in between there was a little bit of fat. The parietal peritoneum continues on the under surface of the diaphragm. It continues onto the abdominal wall, posterior wall and the fascia, endo-abdominal fascia continues down as the transversal fascia on both the sides. So we had to remove them and we can see part of it here which we have removed. That took quite a bit of dissection. And after removing that we could see the muscles and the tendons of the diaphragm. So this is the right dome of the diaphragm, this is the left dome of the diaphragm. This was related to the right anatomical lobe of the liver, this was related to the fundus of the stomach. We have removed all that. So let us take a look at what we can see here. We can see that there is a central portion here. This central portion is the tendon, central tendon of the diaphragm. And inserting onto the central tendon of the diaphragm we have this muscular portion here. If you look closely, this is the muscular portion, the peripheral muscular portion. This is the peripheral muscular portion. So the muscular portion is divided into three parts. The anterior portion is the sternum part, which comes from the sternum, this is the sternum and gets inserted onto the central tendon. Then we have the costal part. This is the left costal part and we can see the direction of fibers very clearly. And this is the right costal part and we can see the direction of fibers going from the ribs towards the central tendon. And then we have the lumbar part, the fibers going from the lumbar vertebrae to the central tendon. This is on the right side and when we look on the left side, we see the fibers running from the lumbar vertebrae to the central tendon. So these are the fibers which get inserted onto the central tendon. So if you look at the direction of fibers and look at them inserting onto the central tendon, we get an idea of how the diaphragm works. When these muscles contract, they pull on the central tendon from both the sides and therefore the central tendon becomes more flat. In other words, the dome for the diaphragm descends down and that is what increases the vertical diameter of the chest wall and allows the abdominal thoracic restoration to take place. So that is the normal restoration which takes place during wide breathing, that is the abdominal thoracic restoration. In this correction, I can mention an important clinical coalition itself. As we know, the diaphragm is supplied by the phrenic nerve. Motor fibers to the muscle component is by the phrenic nerve. When there is a paralysis of phrenic nerve in any one side, let's say for the right side, then when the diaphragm is contracting, only the left side will contract and the left dome will descend down. The right dome will not descend down. And instead of descending down because of the increased intracranial pressure, the right dome will move up. And that will cause decrease in the diameter of the chest wall on the right side. And that is called paradoxical restoration. That happens when there is a unilateral paralysis of the diaphragm. Now let's take a look at the blood supply as we can see then here. This is the abdominal aorta. And we can see arising from the abdominal aorta, this artery here, on the right side, and this artery here on the left side. We can see this is the inferior phrenic artery which arises from the level of T12. This is an important blood supply of the diaphragm. The diaphragm is also supplied on the superior aspect by the superior phrenic arteries, the pedicardial phrenic arteries, the muscular phrenic arteries, which are of the internal thoracic artery. But that we cannot see here. This inferior phrenic artery incidentally also supplies the supranormal gland. We can see the right supranormal gland here and you can see the blood supply going to the supranormal gland. And it also supplies the left supranormal gland which we can see here. And we can see it is supplying the left supranormal gland also. But that is just by the way. Now let's take a look at some special features about the lumbar attachment of the diaphragm. We can see an arch here, almost in the midline. This arch, this is the median arcuate ligament. We can see it arising from the right side. This is going all the way and going like this. This median arcuate ligament is formed by the right crust of the diaphragm which is attached to L123 and the left crust of the diaphragm which is attached from left L12. And in between there is a tendinous portion. This is the median arcuate ligament. So this median arcuate ligament is one place where the diaphragm is attached in the central portion. Now if we were to take a look a little lateral to that. We see this is the suas major and the suas minor muscle. And we can see a ligament structure at the upper limit of the fascia of the suas, this curved structure here. This is the medial arcuate ligament on the right side. Now let's take a look at the medial arcuate ligament on the left side. And again we can see this is the suas major and the suas minor. And we can see the medial arcuate ligament on the left side. So this is another attachment of the diaphragm just lateral to the median arcuate ligament. And to continue further laterally this is the muscle which is the quadratus lumborum. The quadratus lumborum gets attached inserted onto the 12th rib among other insertions. And the upper limit of the quadratus lumborum fascia there is yet another ligament structure here to which the fibroids of the diaphragm get attached and that is known as the lateral arcuate ligament. So this is what we can see on the left side. Now let's switch on to the right side again. This is the quadratus lumborum muscle. And we can see this upper limit of the quadratus lumborum fascia. This is the lateral arcuate ligament which I have lifted up here. This is the lateral arcuate ligament. So lateral arcuate ligament on the right side, the medial arcuate ligament and the median arcuate ligament. So these are the attachments. Just to recap the lateral arcuate ligament is the upper limit of the quadratus fascia. The medial arcuate ligament is the upper limit of the suas fascia. And the median arcuate ligament gives passage to the aorta which I shall mention just a little while later. Let me mention a few quick words about the crust of the diaphragm which I mentioned earlier. As I told you this is the right crust. The right crust is bigger and they are attached to the lumbar vertebra. As it goes up it becomes fleshy and we can see it here. And this fleshy portion curves all the way around this isophagus which we can see here and then it comes back again and we can see the fibres coming back and they get back to the ascending fibres on this side. So this is what constitutes the right crust of the diaphragm and we can see that within the fleshy portion of the right crust of the diaphragm is the isophageal hydras through which buses the isophagus. And this muscle fibres of the right crust they act as lower isophageal sphincter. And further down on the left side we can see this tendinous portion here. This is the left crust of the diaphragm which is smaller than the right crust and which gets attached from l1 to l2. And I have already referred to the two crura forming the aortic margins of the aortic hiatus. The crust of the diaphragm is penetrated by the greater lesser and least sphinctic nerves on the right side and on the left side as they emerge from the thorax to the abdomen. So that is about the crura of the diaphragm and the attachments of the ligaments of the diaphragm. Now let's take a look at the hiatus of the diaphragm. We have three major hiatus and many minor hiatus. The first one that we can see here on the right side, right side of the central tendon. This is the inferior vena cava hiatus and my finger has gone into the cut portion of the inferior vena cava here. This is located at the level of T8 to the right of the midline. This is the cut margin of the inferior vena cava above and this is the other cut margin of the inferior vena cava here. In between this missing portion was inside the liver which has been removed. So this is apart from giving passage to the inferior vena cava. This cable hiatus also gives passage to some of the branches of the right phrenic nerve as they come from the thorax to the abdomen and that's the one which is responsible for referred pain to the right shoulder in case of pathology here and it also gives passage to the lymphatics, right lymphatics from the bare area of the liver to the posterior medias tendon lymph nodes. So these are some of the other structures which go through the cable hiatus. The next one that we can see which I have already mentioned earlier is the esophageal hiatus situated in the right crust muscular portion of the diaphragm. This is located at the level of T10 and we can see that the esophagus is emerging through this right crust. Apart from the esophagus, other structures which emerge from here there are the anterior vagus nerve. We can see it here and the posterior vagus nerve. These are also the structures which pass through the esophageal hiatus and also passing are the branches from the left gastric artery more specifically the esophageal branch of the left gastric artery and the esophageal branches of the left gastric vein. They also pass through the esophageal hiatus and here in this case they constitute what is known as the site of potasystemic anastomosis. Now let's take the next large hiatus which also I have mentioned and that is the aortic hiatus which is at the level of T12. The aortic hiatus as I mentioned is entirely within the median archivate ligament between the two crura, the left crura of the diaphragm and the right crura of the diaphragm and we can see the aorta is emerging through the aortic hiatus. This is the aorta which I have lifted up here. It also gives passage to the beginning of the azygous vein which is formed in the abdomen and it also gives passage to the thoracic duct but we cannot see that here. We are going to summarize cable hiatus, T8, esophageal hiatus, T10 and aortic hiatus at the level of T12. Thank you very much for watching so far. Stay tuned for the next video on the diaphragm.