 Okay, Dr. Sajja Sanyal, Professor, Department Chair. This is going to be a demonstration of the forearm, especially the flexor aspect, the neuro-muscular structures in the muscles. So this is a supine cadaver. This is the right side. The camera person is also on the right side. The narration is also from the right side. The forearm muscles, especially the flexor aspect, are divided into three layers. So let's take the layer number one. We have what is called the PFPF. The first is this muscle that we see here. This is the pronator theories. Flexor-carpyrhidialis. Then there is supposed to be a tendon here called the parmaris longus, which is missing in this particular cadaver. And then we have the flexor-carpyrhidialis. So PFP is missing, flexor-carpyrhidialis F. Secondly, our muscles is the flexor-digiterm superficialis. This is the flexor-digiterm superficialis. And we can see it has got the four tendons, which go to the middle phalanx of these four digits. Then we have the third layer, that is this one here. This is the flexor-polisus longus. Then we have the flexor-digiterm profundus, which I have lifted up here and deepest is this muscle, which we can see here. This is the pronator quadratus. At this juncture, I can mention that in layer number three, between the flexor-digiterm profundus and the pronator quadratus, this space where my finger is located, this is referred to as the space of Parona. This space of Parona is surgically and clinically very important because this is the place where pus and other abnormal pathological fluid can potentially collect and this space communicates with the mid-palmar space of the hand. So if there's a thorn brick or infection in the mid-palmar space, it can track under the flexor at naquillum and come to the space of Parona. The flexor group of muscles, they take origin from the common flexor origin, that is the medial epicondyle where my index finger is located. However, there are a few variations. The proeteteris takes origin from the humeral and it also has got an origin from the ulnar. So therefore, the proeteteris has got two heads and we can see the two heads here. This is one head, the humeral head and this is the ulnar head. Similarly, the flexor dystrum superficialis has also got two heads. It has got a humeral ulnar head and it has got a radial head. The radial head takes origin from the anterior oblique line of the radius. The significance of these heads will be obvious a little later. Though it is visible in this dissection, it is not a muscle of this compartment, namely this muscle here. This is the brachioradialis muscle. This is actually supplied by the radial nerve, but it is visible in this compartment. But it does not belong to this compartment. Now, let's come to the neurovascular structures. Let's take a look at this. This is the medial nerve. And we can see the medial nerve is formed by the medial and the lateral roots of the medial nerve from the respective cords, the brachial plexus and it comes down on the medial side. It goes through the cubital fossa. The medial nerve passes between the two heads of the proeteteris. This head and this head and we can see the medial nerve is passing through that. Then it passes through the two heads of the flexor digital superficialis, which I mentioned just a little while back. And then it comes here, and this is the continuation of the medial nerve. And if you see, when I exert traction here, it is moving there. If the palmaris longus had been present, it would have been present between the flexor carpare radialis and the palmaris longus tendon. And this is a site where we can give local anesthesia and do a regional block. And after that it passes under the flexor diagonal into the palm. Well, it is passing between the two heads of the proeteteris. The medial nerve can get entrapped and that is referred to as the pronator syndrome. When the patient will have pain in the cubital fossa and will have numbness, stinging and peristicia in the palm and the radial side of the hand. The medial nerve as it passes under the carpal tunnel, it can produce carpal tunnel syndrome by virtue of compression because the carpal tunnel is occupied by nine tendons. Four tendons of the flexor digitrum superficialis, four tendons of the flexor digitrum profundus and the flexor palmaris longus. So, therefore the medial nerve can get compressed. However, the ulnar nerve never gets compressed because it is over this flexor adeniculum. Medial nerve injury as I mentioned occurs when there is a carpal tunnel syndrome and then it can produce weakness of the thinar muscles. The point to be remembered is as the medial nerve goes through the carpal tunnel, it gives a cutaneous branch which goes above the carpal tunnel and that is the one which supplies only the palmaris skin. So, therefore in carpal tunnel syndrome the palmaris skin is spared. The next neurovascular structure is this one which I have lifted up. This is the brachial artery with its accompanying vinaecomitantes and we can see the brachial artery is coming down from the arm. In the cubital fossa the brachial artery divides into two main branches and we can see the two branches here. This is the radial artery. The radial artery runs under cover of the brachioradialis and we can see that it's running here and it runs down. It gives only a radial recurrent branch and then it goes under the brachioradialis and we can see it is running under the brachioradialis and then it crosses the anatomical snuff box and then it pierces the first dorsal intratrus muscle and forms a deep palmar arch. This radial artery position is the one which we can feel against the lower end of the radius and that is the radial pulse which is normally felt in clinical practice. The other division of the brachial artery is this one here. This is the ulnar artery. The ulnar artery goes betaly. It goes deep to the muscles and we can see the ulnar artery here and when I exert traction here we can see it is moving here. This is the ulnar artery. The ulnar artery runs under cover of the flexor carpi ulnaris and here it crosses to the palm and it forms a superficial palmar arch. The neurovascular plane is between layers two and three that is it is between the flexor digital superficialis which is layer number two and the flexor digital profundus which is layer number three. That is the neurovascular plane. To continue with the neurovascular structures the next structure that we can see here is this nerve here. This is the ulnar nerve. This trace the ulnar nerve right from the arm. This is the ulnar nerve coming from the medial cord of the brachial plexus and here we can see it is disappearing. The ulnar nerve goes behind the medial intramuscular septum and if we were to slit open the medial intramuscular septum we will see it is running behind that and here it is accompanied by the ulnar collateral arteries which is branches of the brachial artery. The ulnar nerve then goes behind the medial epicondyle. In fracture of the medial epicondyle the ulnar nerve can be injured. After that ulnar nerve goes through a tunnel which is referred to as the cubital tunnel. This cubital tunnel is a unique tunnel which is formed by the aponeurosis of the flexor carpi ulnaris muscle which I mentioned here. It gives an aponeurotic fascia which merges with the anti-brachial fascia and it gets attached to the subcutaneous border of the ulnar and that tunnel bridges from the medial epicondyle to the olecranal process. So the ulnar nerve passes through the cubital tunnel and then it runs under cover of the flexor carpi ulnaris and this is the ulnar nerve that we can see here. Then it goes superficial to the flexor reticulum and it comes to the palm and it supplies the medial side of the palm. The ulnar nerve supplies the flexor carpi ulnaris and it supplies the medial half of the flexor digitorum profundus which is this muscle here. The medial nerve supplies the rest of the muscles of the flexor aspect. If there is an injury of the ulnar nerve proximally then it can produce claw hand and this claw hand is typically called the radial claw hand. On the other hand if the ulnar nerve is injured distally like for example handlebar neuropathy or fracture of the hook of hammock or what is known as the gion tunnel syndrome then it produces ulnar claw hand. To continue with the other neurovascular structures the next one that we can see here is this nerve here. This is the radial nerve. The radial nerve comes in front of the lateral epicondyle and it is under cover of the brachioradialis. So we have retracted the brachioradialis to show them the radial nerve. The radial nerve under cover of the brachioradialis divides into a superficial branch and a deep branch. The superficial branch is cutaneous and we can see this in the superficial branch. The superficial branch runs under the brachioradialis again in accompaniment with the radial artery and it runs across and then it again crosses the anatomical stump box and it supplies the skin of the gorsum of the hand. The deep branch it first supplies the extensors of the wrist and therefore this radial nerve if it's injured in the elbow like for example dislocation of the elbow or superior radial ulnar joint dislocation. If the radial nerve is injured it can produce a wrist drop. After that it pierces through a muscle which is not visible here that is the supinator muscle and then it becomes known as the postient rossus nerve and after that the deep branch of the radial nerve which is visible here it supplies all the muscles of the extensor compartment which are visible here. So we have seen the median nerve we have seen the brachial artery the two branches we have seen the ulnar nerve we have seen the radial nerve just to complete the story we can see one nerve here this is the lateral cutaneous nerve of the forearm this is the continuation of the muscular cutaneous nerve and you can see it is running between the biceps and the brachialis this runs with the cephalic vein and we can see this is the cephalic vein and this supplies the skin of the antrolateral aspect of the forearm and concomitantly this is another nerve that we can see here this is the medial cutaneous nerve of the arm and the forearm this accompanies the basalic vein and we can see the other cut end of this and this supplies the medial side of the arm and the forearm so these are two superficial nerves and the two superficial veins which are visible in this neuromascular structure so these are the structures which I wanted to show you in the forearm and if you have any questions or comments please put them in the comment section below Dr. Sanjay Sanyal signing out Mr. Kendall Kambor batch is the camera person have a nice day