 So this is going to be a demonstration of the thoracic wall anterior thoracic wall, which we have removed from this cadaver here Now I'm going to turn the chest wall and I'm going to show the inner surface So now we are seeing the inner surface of the chest wall First of all we can see this is the manoeuvrabium sternum There's the body of the sternum. This is the zephyte process We can see two muscles attached to the manoeuvrabium sternum. These are the muscles of the infrared strap muscles of the neck namely The sternum thyroid and the sternum hyoid. We shall not talk about them any further This shiny structure that we see here and we can see it very closely when I lift it up and we can see that here This is the parietal peritoneum. The parietal peritoneum is very thin and it is misothelial like And now further laterally on this side we have removed the parietal peritoneum and we can see this membrane structure here This is the endothoracic fascia, but the endothoracic fascia is thick And this is the one which may have a little bit of fat also as we can see here And this is the one which covers the muscles and here we can see the internal intercostal muscles much more clearly after removing the endothoracic fascia The innermost intercostal the subcostal and the transversal thoracis are the layer number three and Between layers two by three is the neuro vascular bundle We cannot see the innermost intercostal and the subcostal because the subcostal muscles are usually Located more on the posterior aspect in relation to the angle of the ribs But we can see the transversal thoracis muscle here We can see these fibers going up from the lower end of the sternum internally and slips of muscle fibers are going up like this Similarly on this side also we can see These are the transversal thoracis muscle fibers They also belong to the same pair that is the layer number three and I'm going to reflect it just now Now let's take a look at the neuro vascular structures. First, let's take a look at the intercostal nerves So we have removed the endothoracic fascia to show the intercostal nerves I have picked up the intercostal nerve below the second rib here We can see it here Then this is the third intercostal nerve This is the fourth intercostal nerve This is the fifth intercostal nerve and this is the sixth intercostal nerve The next structure which we notice are these Blood vessels on either side of sternum. This is the internal thoracic artery and vein also called the internal mammary artery and vein We notice that the vein is located medially and the artery is located laterally Above the second rib it is a distinct vein Below the second rib it becomes a vinae commitante and we can see the vinae commitante of the vein Accompanied the artery. The internal thoracic artery comes from the first part of the subclavian artery Internal thoracic vein drains into the brachial cephalic vein on each side The internal thoracic artery gives rise to two anterior intercostal arteries in each space And these last almost with the posterior intercostal artery and the collateral branch of the posterior intercostal artery in the intercostal spaces The internal thoracic artery gives anterior intercostal arteries up to the sixth space This is the sixth space and From the seventh to the ninth space a branch from the internal thoracic called the muscular phrenic gives the anterior intercostal arteries The 10th and the 11th space do not have any anterior intercostal arteries So therefore, let us reflect the transversal thoracic muscle on this side to show the course of the internal thoracic artery So I have reflected the transversal thoracic muscle on this side and we notice that the internal thoracic artery as it comes down It runs between layers number three, which is the transversal thoracic and layer number two Which is the internal and we find that as it goes down. This is the Seventh rate. This is the sixth rate. So therefore, this is the sixth intercostal space till here It gives this branch. This is the anterior intercostal artery and after that it divides into a muscular phrenic Which has been removed here along with the structures of the abdominal wall and superior epicastric Which runs into the anterior abdominal wall. So that is how the internal thoracic artery Terminates by dividing into a muscular phrenic and superior epicastric. That is why a little while back I mentioned that the muscular phrenic artery, which is one of the terminal branches of the internal thoracic Gives anterior intercostal branches to the seventh, eighth and ninth space So these are the structures that we can see on the inner surface of the chest wall and with the neuro vascular contents Before I conclude I need to tell you some very important clinical correlations. The internal thoracic artery is used for coronary artery bypass drafting, especially the left side and it is known as left internal mammary artery bypass. The advantage of that is One end is already attached to the supply vein artery. So therefore only the distal end needs to be cut and anastomers to the Coronary artery beyond occlusion. That is one important clinical use of the internal thoracic artery Now let me again turn back the structure here When we need to do a procedure called pericardiocentesis We use the left side of the cv sternal joint in this position here And we insert the needle into the pericardial space where my instrument has gone in This area is referred to as the bare area of the pericardium because in this region The parietal pleura moves a little away from the chest wall and therefore the hyperus pericardium is in direct contact with the chest wall So therefore we can do a pericardiocentesis without entering into the Pleura and finally There is one approach for thoracotomy that's called the anterior approach where what we do is what I am doing right now We split the pericardium by means of an edge-shaped incision We make a transverse cut like this as I've done with my instrument and then we make Vertical cut and a vertical cut and we lift up the pericardium up and down and we shall have the cartilage from under the So like that we get to in several spaces and then we can enter the thoracic wall anterior This is the anterior thoracotomy of course There are other procedures something called a posterior lateral thoracotomy where we cut through the rib We reflect the periosteum and we enter through the bed of the rib That gives us the space above and the space below and a greater exposure That is what we do for a posterior lateral thoracotomy So these are some of the surgical procedures and clinical applications of the chest wall. Thank you very much for watching Dr. Sanjay Sanyal signing out. If you have any questions or comments, please put them in the comment section below. Have a nice day