 Let's look at the muscles of the upper appendage now. As you see for reference, this is the left arm appendage that we're looking at. And we're going to start up here at the more proximal side and look at the muscles up here at the shoulder. So this first muscle to show you is the deltoid muscle and you can see that it's got that delta shape to it, like a triangle. So this is the deltoid muscle and you remember that it inserts on the humerus bone right behind here on the deltoid tuberosity. And it originates, its origins are on the spine of the scapula and the clavicle. So again, that's the deltoid muscle. So I'm going to take the deltoid off and show you some of these muscles that are a little bit deep to the deltoid. The next set of muscles I want to show you, there's four of them and these are called the rotator cuff muscles. And you'll notice on this anterior side, remember this is the anterior side of the bone, and it sits at a slight angle, here's your scapula. This sits at a slight angle so this muscle is underneath the scapula so it's called the sub scapularis muscle. So this one is sub scapularis muscle. Then if we come around to the posterior side of the scapula, you see the scapular spine right here and you see a muscle that's superior or above the spine of the scapula. So this one is called supraspinatus muscle. One word, supraspinatus muscle. And then if we come inferior to that scapular spine, you see a large muscle right here. This one is infraspinatus muscle. Infraspinatus muscle. And then the fourth one of this group called the rotator cuff group is this here, this one is called the teres minor muscle. Teres means round and this is teres minor. So those are the four muscles of the rotator cuff. If you want to practice those, what was this one called? You could say it or try to spell it. And then what's this one? And then this one. Now there is one more muscle in this area. It's just not part of the rotator cuff muscle group. And that is this muscle here. This one is teres major. This one is teres major. So if the muscles sit vertically on us, then the top one, the more superior one is the minor and the lower one, the more inferior one is the major. So remember, in baseball, you have to get to the minors before the majors. So if when the muscles are vertical, the minors are on top and the majors are next. So you have to get to the minors before the majors. So again, teres major. Now on these muscles of the upper arm, let's go back to the anterior side again. And you see this muscle here. This is the biceps brachii. And you probably know that the biceps flexes your arm anyway. So this is biceps brachii. And it has two heads to it. Long head and the short head. So it's called biceps. Biceps brachii. Let's come laterally on the arm here, this upper arm. And we see a muscle that's simply named for this upper area, which is the brachial area. So this one is called brachialis. You just put an IS on the end of brachial. You have the muscle named brachialis. And then on the posterior side, we have the muscle back here that has three parts to it, three heads of attachment. So this one is called triceps brachii. Triceps brachii. So you have the lateral, the long and the medial head. So triceps brachii. Why don't you try those now for practice? What's this one? Then this one. And those are the muscles then of the upper part of the arm.