 So, this is going to be a demonstration of the arm and the cubital force. This muscle that you see in front of us, this is the biceps brachial. And we can see that as the term implies, it has got two heads. So, this is the long head of the biceps, which arises from the supraglinar tubercle and passes through the shoulder joint. And this is the short head of the biceps, which takes origin from the corocid process. And the two heads then unite from the belly of the biceps. And the biceps tendon then gets inserted. And you can see this is the tendon here, it gets inserted onto the radial tuberosity. And as it gets inserted, it gives off an aponeurotic expansion. And we can see the expansion, which we have cut here. This is one end of the other portion. This is the biceps aponeurosis. This biceps aponeurosis runs medially. It reinforces the roof of the cubital fossa and it merges with the anti brachial fascia. And we can see that all happening here. So, we have cut it and reflected one half of it and the other half of it. So, this is the biceps aponeurosis. So, the biceps aponeurosis is an extension of the tendon itself. So, this is the biceps. The biceps is a powerful supinator under force, like turning a screwdriver. And it is also a flexor when the arm is fully supinated. It is supplied by the muscular cutaneous nerve. This is the case that the author attended to showing rupture of the long head of the biceps tendon on the right side. The next muscle that we can see here once we reflect the biceps is this muscle. This is the coracobrigales. It also takes origin from the coracoid process and gets inserted onto the humerus on the medial aspect. This is referred as a landmark muscle. Why is it called a landmark muscle? Because its insertion marks the location of the entry of the muscular cutaneous nerve. So, it acts as a landmark. And this is also the location where we cannot see though in this clearly is a humeral nutrient artery will enter the humerus. In this location, sometimes the coracobrigales can entrap either the brachial artery or the medial nerve. But that is not very common. The coracobrigales acts mostly on the shoulder joint. This is also supplied by the muscular cutaneous. And the third muscle that we can see here is this after we have retracted the biceps. This is the brachialis. This is the brachialis. The brachialis takes origin from the humerus and it gets inserted onto the anterior surface of the coronite crosses of the ulna. It is the most powerful workhorse flexor of the elbow in all positions of the elbow. And this is also supplied by the muscular cutaneous nerve. The brachialis can also be supplied sometimes by a branch of the radial nerve. And the brachialis also forms the part of the floor of the cubital fossa. So, that brings me to the muscular cutaneous nerve itself. And we can see this is the muscular cutaneous nerve. This is arising from the lateral cord of the brachial flexors. And we can see it is entering the arm at the insertion of the coracobrigales. We can see that clearly here. It supplies the coracobrigales and then it comes here. And we can see it's running. It runs between the biceps and the brachialis. And we can see it is giving multiple branches to the biceps and the brachialis. And then it continues and it runs between the two. And we have retracted it here to see the other side. And lower down it passes between the biceps and the brachialis. And it becomes known as the lateral cutaneous nerve of the forearm. And here it runs with the cephalic vein. That is the reason why this is called the muscular cutaneous nerve. And lateral cutaneous nerve of the forearm supplies the skin of the forearm up to the base of the thumb. Here again, there's a clinical correlation when the nurse or anybody tries to take a blood sample from the cephalic vein. If there is extravization of blood here, it can produce irritation of the cutaneous branch of the muscular cutaneous and can produce numbness, tingling, and peristhesia in this region. And it is a very common condition. So these are the muscles and the structures that we can see here. Now let's trace this artery here. This is the brachial artery. The brachial artery runs on the arm. And it enters the cubital fossa. And in the cubital fossa, it divides into a radial artery and an ulnar artery. The next structure that we can see here is this nerve here. This is the median nerve. The median nerve initially is a little lateral. Then it runs in front. And then it comes medial to the brachial artery. The median nerve then passes between the two heads of the pronator teres. And then it passes between the two heads of the flexor digital superficialis and it enters the forearm. So these are the structures that we can see in the arm. Let me show you the cutaneous nerves and the cutaneous veins which are visible here. Let's take a look at this vein that we can see arising from the radial side of the forearm. And we can trace it here. And we can see that it is running up like this on the lateral side of the arm in the delta vector groove. This is the cephalic vein. And it is also giving a communication which is running on the medial side. This is the basillic vein. And if you trace the basillic vein up, I will draw your attention to the brachial artery. Can we see a vein accompanying the brachial artery on either side? This is the vene comitante of the brachial artery. The vene comitante. So the vene comitantes of the brachial artery continue up and they form a single vein. This then merges with the basillic vein. And the two together then form the axillary vein. And the axillary vein then continues up. So this is the formation of the axillary vein. This is the median cubital vein, which runs on the surface of the cubital fossa. This is a very common site of vene puncture. Even the cephalic vein is used. The basillic vein is used for vene section when we want to maintain an intravenous line for long-term intravenous IV fluid infusion. The basillic vein is accompanied by this nerve here. And we can see this nerve here. This is the medial cutaneous nerve of the arm and the medial cutaneous nerve of the forearm. Just like the cephalic vein, while we're doing a vene section, we may injure the medial cutaneous nerve of the arm or the forearm. Thank you very much for watching. Dr. Sanjay Sanyal signing out. David O is the camera person. My MD1 students are my assistants. If you have any questions or comments, please put them in the comments section below. Have a nice day.