 Good day everybody. This is Dr. Sanjay Sanyal, Professor Department chair. This is going to be a demonstration of the structures in the arm. So this is the right side. Supine cadaver, I am standing on the right side and I am holding the camera. So this muscle that we see in front of us, this is the biceps muscle and this tendon that we see, this is the short end of the biceps. It takes origin from the coracoid process here and further laterally, this is the long little biceps. The tendon takes origin from the supraglena tubercle and then the tendon passes through the shoulder joint and then it comes out through that under the transverse humeral ligament and the muscle becomes fleshy and unites with the short end of the biceps to form the biceps tendon and I have lifted up the biceps muscle here. The biceps tendon insertion is this one here. The main insertion is deep inside, which we shall demonstrate when we are opening out the cupidal fossa and it gives a medial expansion, which is called the bicep metal aponeurosis. The biceps, as we know, it is a both. It's got a flexion action of the elbow and as well as supination. It flexes the supinated elbow and it supinates the flexed elbow. That's the easiest way to remember the basic function of the biceps. In elderly persons, due to degenerative wear and tear, the long head of the biceps tendon, it can rupture and when it ruptures, this muscle, it forms a bulge here where the person tries to flex his elbow and that is called the Popeye deformity and it produces a depression above here, which is called the Popeye sign. The biceps muscle is supplied by the musculocutaneous nerve and we can see, I have retracted here and we can see this is the musculocutaneous nerve. Under the biceps, we have the brachialis muscle. Under the biceps, this is the brachialis muscle. Brachialis muscle takes origin from the front of the hubris and it is getting inserted onto the cornoid process of the ulna, which you cannot see in this dissection. This brachialis is the most powerful flexor of the elbow in all positions of the elbow, unlike the biceps, which can flex the elbow only when it is in the supinated position. The brachialis is also supplied by the musculocutaneous nerve and we can see that here. The musculocutaneous nerve runs between the biceps and the brachialis and it supplies both and then it emerges out laterally and we can see it is emerging here and then it becomes known as the lateral cutaneous nerve of the forearm and it runs in a complement with the cephalic vein and it supplies the skin on the entrolateral aspect of the forearm. So this is that's why this nerve is called the musculocutaneous nerve. Unlike the biceps, which is a two joint muscle, that means it crosses the shoulder joint and the elbow joint, the brachialis muscle is a single joint muscle and the brachialis muscle also gets a dual nerve supply. It can get a branch from the radial nerve, but we do not see that in this particular dissection. The next muscle in the anterior compartment of the arm is this muscle here. This is the coraco brachialis. I'm tracing the coraco brachialis. The coraco brachialis also takes origin from the coracoid process and it gets inserted onto the medial side of the humerus. That's why it's called coraco brachialis. This coraco brachialis is considered as a landmark muscle. Why is it called a landmark muscle? Because of two reasons. Number one, it marks the location where the musculocutaneous nerve enters into the arm. That's one reason. And the other reason is it also marks the location where we have the humeral nutrient artery. It enters the arm. So therefore, this is called the landmark muscle. This coraco brachialis rarely can produce entrapment neuropathy of the median nerve and or the brachial artery, but that is not very common. The coraco brachialis crosses only the shoulder joint. Therefore, it's got a weak action on the shoulder. It produces flexion of the arm and the shoulder joint. The coraco brachialis is also supplied by the musculocutaneous nerve. So these are the three muscles that we can see in the anterior compartment of the arm. That's all for now. In the next dissection, I'm going to mention all these neurovascular structures that I have dissected out in the medial compartment as well as in the anterior compartment of the arm. Thank you very much for watching. Dr. Sanjay Sanyal signing off. If you have any questions or comments, please put them in the comment section below. Please like and subscribe. Have a nice day.