 This is going to be a demonstration of the region of the wrist and the proximal part of the palm, the carpal tunnel and the space of Paravana. So let's take a look at the structures that are visible in front of us. We can see this tendon here. This is the flexor carpal radialis. Then we can see yet another tendon, a very small, very narrow tendon. In this particular cadaver it is especially narrow and that is this one here. This is palm raise longest tendon. So we have the flexor carpal radialis and the palm raise longest tendon and running exactly in the middle of these two we have this nerve here. This is the median nerve. So this is the important structure which is present in the proximal part of the wrist and this is the site where we keep a median nerve block. The median nerve is the most important structure as far as the nerve is concerned which goes through the carpal tunnel and we shall show the carpal tunnel just now. We have already slit open the flexor retiniculum and we will show the margins of the flexor retiniculum just now. This is one cut margin and we can see that it is quite thick and quite strong. It is almost a cartilaginous feel. So this is one cut margin of the flexor retiniculum. If you look very carefully you will see the other cut margin of the flexor retiniculum on this side and this is the other cut margin of the flexor retiniculum. And again when we feel it we feel that it is quite thick and strong. So this was bridging over in this space and that space is called the carpal tunnel. What are the boundaries of the carpal tunnel? On the median side we have pissiform bone. The pissiform bone is the one which gives attachment to this tendon. This is the flexor carpal ulnaris. Then we have the scaphoid on the radial side. Then we have the trapezium just distilled to that. And then again going back to the median side we have the hook of the hammet. So therefore we can imagine a triangular space and bridging across the triangular space it was the flexor retiniculum which we have cut and the space under that is the carpal tunnel. And now I am going to put my finger inside and my finger is now in the carpal tunnel. Having mentioned that now let us take a look at what are the tendons which are passing through the carpal tunnel. This tendon which I picked up here this is the flexor digitorum superficialis. There are four tendons. They were all enclosed in their sand away sheath. The next structure which passes through the carpal tunnel is this tendon which I have picked up here. This is the flexor digitorum profundus. This also has four tendons. So four plus four eight tendons and the there is a ninth structure which passes through the carpal tunnel and that is this tendon here. This is the flexor polisus longus. All these tendons are enclosed in their respective sand away sheath. So let me mention quickly about the sand away sheath. The flexor polisus longus has got its own individual sand away sheath and as it goes to the thumb and that sand away sheath is referred to as the radial purse. The flexor digitorum superficialis and the profundus they have a combined sand away sheath and that goes up to the other four fingers. There is of course a gap in this region. This combined sand away sheath is referred to as the ulnar bursa. If there is any thorn prick or an infected prick of the tips of the fingers especially the little finger then infection can travel to the ulnar bursa and that is known as tino sinobitis. Similarly if there is any infection or prick thorn prick of the thumb infection can travel to the radial bursa and that is known as radial tino sinobitis. So that is about the sand away sheath. Apart from the nine tendons what other structure passes through the carpal tunnel. As I mentioned a little while back this is the median nerve. The median nerve came from the forearm. It pierced through two muscles and we saw the median nerve between the flexor carpal radialis and the palm bursa longus. The median nerve then goes through the carpal tunnel and in this position if you put my finger in we find that the carpal tunnel is highly crowded and this is the place where the median nerve can get entrapped. It can produce this condition known as carpal tunnel syndrome where the patient will have weakness of the thinner muscles but there will be no loss of sensation on the palm because a palm or cutaneous branch goes outside the carpal tunnel. When a patient has got carpal tunnel syndrome the treatment is to slit open the flexor retiniculum and that is exactly what we have done here. We can see one cut margin of the flexor retiniculum here and the other cut margin of the flexor retiniculum is here. Nowadays it is not done by open surgery instead it is done by endoscopic surgery through the skin itself. The point to be remembered is when we are slitting the carpal tunnel by cutting the flexor retiniculum we have to safeguard the recurrent branch of the median nerve which supplies the thinner muscles. So, let us take a look at the recurrent branch of the median nerve and we can see that here. This is the median nerve and we can see it is giving a branch here. This is the recurrent branch of the median nerve which supplies the thinner muscles. This has to be safeguarded. Then there can be communication between the median and the other nerves that also has to be safeguarded during carpal tunnel surgery. So, these are some of the structures about the carpal tunnel. 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 Sanyal signing out. Have a nice day.