 So this is a dissection of the right side supine cadaver. I'm standing on the right side. My camera person is also on the right side towards the headed. So we have completely opened up the axilla, the right arm, right cubital fossa to show the neurovascular structures in the muscles. So this muscle that we see in front of us, this is the coracobrachialis. This takes origin from the coracod process and it gets inserted onto the major side of the middle of the humerus. This muscle that we see here, this is the biceps brachialis. Incidentally, this is the reflected bactralis major. So come back, this is the biceps brachialis. These are the two heads of the biceps brachialis. This is the short head taking origin from the coracoid process. And this is the long head which was inside the tunnel produced by the transverse humeral ligament. And the long head then takes origin from the supraglinoid tubular scapula. And these two then unite from the belly of the biceps and we can see the biceps tendon is coming down here and the tendon is getting inserted here. This is the tendon getting inserted in the cubital fossa on the radial tuberosity. And as it gets inserted, there may be a bursa underneath. At the same time, we can also see that it is giving this aponeurotic expansion majorly which we have cut. This is the major side. And this is the other cut portion of the aponeurotic expansion on this side. This is the biceps aponeurosis. The biceps aponeurosis reinforces the roof of the cubital fossa and also reduces the pressure of the biceps tendon on the radial tuberosity. Once we reflect this biceps, we see the next muscle underneath. This is the brachialis. The brachialis takes origin from the anterior surface of the humerus and it descends down from the floor of the cubital fossa and it gets inserted onto the anterior surface of the coronoid process of the ulna. This is the musculocutaneous nerve that we can see here coming from the lateral cord of the brachial plexus. I have lifted it up. It enters the arm at the point of insertion of the coracobrachialis. And therefore this coracobrachialis muscle is referred to as a landmark muscle because it indicates the location of the entry of the musculocutaneous nerve as well as the site of the nutrient artery to the humerus. The musculocutaneous then supplies the coracobrachialis and then it runs between the biceps and the brachialis as we can see here. And then it supplies both these muscles and then it comes out between the two laterally and it becomes known as the lateral cutaneous nerve of the forearm. If there's injury to the musculocutaneous nerve which is not very common but can happen then there will be paralysis of the flexors of the elbow namely the biceps and the brachialis. However, the patient will still be able to weakly flex the elbow by virtue of the brachioradialis which is supplied by the radial nerve. I want to mention another clinical correlation pertaining to the biceps. The biceps is the two heads. As I mentioned, this is the long head. The long head can rupture in old age due to degenerative wear and tear in which case the rest of the biceps will bunch down here and there will be a hollow in this region when the patient tries to flex the arm and this is referred to as pop-eye deformity which can be seen in certain people in old age. This is the clinical picture of a patient that the author tended to showing pop-eye deformity. The next muscle that we can see here in the cubital fossa is this one here. This is the pronator tiris. This forms the infromedial boundary of the cubital fossa and this muscle that we see here, this is the brachioradialis which forms the infromedial boundary of the cubital fossa. So, having mentioned these muscles, now let's take a quick look at the neurovascular structures. Let's start with the superficial most vein that we can see here which we have preserved very carefully. This vein that we see here, this is the cephalic vein. This is formed on the radial side of the arm, forearm and as it ascends up, it runs in the delta pectoral groove, namely the groove between the deltoid and the pectoralis major. This is the deltoid muscle. Then it goes through the delto-pectoral triangle or the gliby-pectoral triangle and pierces the gliby-pectoral fascia or the costa-corocate membrane and it opens into the axillary vein and we can see that here. As it's running up, it gives the communication across the groove of the cubital fossa which we can see here. This is the median cubital vein which communicates with the basalic vein and that we can see here very clearly. This is the basalic vein which runs on the medial side of the arm. This basalic vein then runs up and it unites with the vena commitantes of the brachial artery and it ultimately forms the axillary vein which we can see here. This basalic vein is accompanied by this nerve which we can see here. This is the medial cutaneous nerve of the arm and further down it is the medial cutaneous nerve of the forearm and we can see it is coming out from the medial or the brachial plexus. While we are talking about the nerves accompanying the superficial vein, let me mention that the semantic vein is also accompanied at part of the distance by this nerve here. I have reflected the brachyceps to show this nerve here. This is the terminal part of the muscular cutaneous nerve. Muscular cutaneous nerve after it is supplied, the coraco brachialis, the biceps and the brachialis, we can see it is running between the two and then it becomes cutaneous and it becomes known as the lateral cutaneous nerve of the forearm and in this place it is accompanied by the sabalic vein. The clinical significance of this is that this vein is quite often used by the nurses and other people for venisection and venipuncture and in so doing, if there is extravagant of blood, it can produce irritation and numbness tingling peristicia along the distribution of this lateral cutaneous nerve of the forearm, which is the terminal branch of the muscular cutaneous nerve. Likewise, the spatial vein is also used for many sections. If there is extravagant of blood, it can produce irritation of the medial cutaneous nerve of the arm and the medial cutaneous nerve of the forearm. Now let's take a look at other structures in the cubital fossa. Going from medial to lateral, we have this structure here. This is the medial nerve and we can see that the medial nerve is found in the axilla by the lateral root of the medial nerve and the medial root of the medial nerve, coming respectively from the lateral cord and the medial cord and the two unite to form the medial nerve. The medial nerve initially is lateral to the axillary artery. It then crosses in front and then it becomes medial to the brachial artery in the cubital fossa. Up to the medial nerve, we have the next structure here. This is the brachial artery. The brachial artery is the continuation of the axillary artery. We can see this muscle here. This is the teres major. So therefore, after the teres major, the axillary artery becomes known as the brachial artery and my finger is tracing it. This brachial artery runs just lateral to the medial nerve in the cubital fossa. These two structures, the medial nerve and the brachial artery, can be injured in supracondylar fracture of the humerus in children as well as anterior dislocation of the elbow, which is also quite common in children, in which case we have to reduce them immediately. Otherwise, there will be jeopardization of the blood supply and or the nerve supply to the still part. This is the next way to show anterior dislocation of the humerus. This is likely to injure the neurovascular structures of the cubital fossa. The next structure I have already mentioned is the tendon of the biceps. And finally, if I retract the brachioradialis, we can see this nerve here, which I am going to lift up now. This nerve. This is the radial nerve. The radial nerve comes from in front of the lateral epicondyle and here, under the brachioradialis, it divides into a superficial division which runs under the brachioradialis and the deep division, which we can see continuing here. This is the deep portion of the radial nerve, which supplies not only the brachioradialis, but it also supplies the muscles on the extensor aspect of the forearm. Therefore, in the cubital fossa, the structures from medial to lateral are medial nerve, brachial artery, the biceps tendon and the radial nerve. Supia boundary is an imaginary line joining the medial epicondyle, where my right index finger is located and the lateral epicondyle, where my left index finger is located. This is supia boundary. Infromedial boundary is the proentoterias and the infrolateral boundary is the brachioradialis. This median nerve, as it progresses down, it goes through the two heads of the proentoterias, namely the humeral and the ulnar head, where it can get entrapped to produce the condition known as pronator syndrome, where the patient will have pain in the cubital fossa and numbness and tingling in the distribution of the medial nerve. These are some of the clinical correlations pertaining to the arm and elbow. That's all for now. Thank you very much for watching. Dr. Sanjay Sanyal, please like and subscribe if you have any questions or comments. Please put them in the comment section below. Have a nice day.