 All right, good day, and today we're going to be actually talking about the pectoral girdle, which is actually one part of the appendicular skeletal system. Now, you probably have already learned about the axial skeletal system. So just to kind of put the appendicular in its appropriate context, the axial skeletal system, as you can kind of see really from the skeleton, consists of the skull, the vertebral column, and the thoracic cage. Essentially, it's in the center part of the body. Now, the appendicular skeletal system, on the other hand, and the term appendicular or appendage, think of it as hanging off. Consists of the bones like the girdles that we'll be talking about that connect to the axial skeletal system. And the term girdle actually means belt. So almost think like it's a belt kind of holding the limbs, essentially, to the axial skeletal system. Now, the appendicular skeletal system is going to really consist of four major parts. And of course, there are several bones in each of the parts. The pectoral girdle, which is basically the chest girdle, is going to consist of two bones, the clavicle and the scapula. And that's going to be our major focus today. That's going to then connect to the upper limbs. Then we have the pelvic girdle, which we'll probably talk about in a later video, and then the lower limb. But today, let's just talk about the pectoral girdle. So it's important whenever you're looking at the skeletal system to kind of first get an overall perspective of what you're looking at. So because you essentially are going to see patients or people as a whole, you're not going to see individual bones necessarily. But if you can kind of look at the pectoral girdle on this skeleton, it consists of the clavicle. And you can kind of see that the clavicle is mostly in the anterior side of the skeletal system. And then essentially the scapula, which is on the posterior side of the skeletal system. One other thing to remember about the appendicular skeletal system is that there are two of each of these bones, because essentially you have two upper limbs and you have two lower limbs. And the two sides are not going to be identical to each other. They are essentially going to be mirror images of each other. If I was to look at this scapula here, which is essentially from the right side of the body, notice it has similar features, but I can't put it exactly on top of this scapula because it's from the different side of the body. So really when you learn these bones, it's important to try to know what features are on, say, the anterior side, the posterior side, the superior side, the medial side, the lateral side, and the inferior side. So the first bone we're going to actually look at today is the clavicle. Now, if you look at this bone, it kind of looks like a little S. And it doesn't look like there's really much to it. And you're like, well, why do we need this bone here in the first place? Well, this is actually the only direct connection between the upper limb and the axial skeletal system. There is no other direct connection here. And so the clavicle actually has two major connections. It has one to the upper part of the sternum called the manubrium and another to the scapula, which we'll talk about next, and specifically an area called the acromion. Now, the clavicle is going to kind of act like a brace or a scaffold and help to really hold, as you can see, hold the upper limb lateral to the body. Now, if that clavicle essentially was not there or it was broken, which, by the way, is a very common sports injury, a broken clavicle, especially if you get hit in just the right position in the shoulder, or especially if you take a fall and you, a hard fall and you use your hands, a lot of the force is going to get sent to the clavicle. But if you break this, then the shoulder, especially because of the muscles and the weight of the arm, is going to have a tendency to want to collapse inferiorly and anteriorly. And especially if you have ever had a clavicle break or fracture, then they always try to stabilize that because it can really affect the mobility of your arm. So that's the clavicle. And the other major bone of the pectoral girdle is the scapula. And this one looks a little more interesting. It's got a lot of little depressions and processes on it. And once again, when you're trying to learn about bones, you need to identify not only the name of the bone, but also a specific bone markings on the bones. And it's important, once again, to know which of these bone markings are on which side, whether we're talking about the anterior or posterior or superior or essentially lateral sides. So looking at this as a whole, the scapula as a whole, notice that it has really two major connections. It connects with the clavicle, but it also is going to connect with the bone of the arm, which is essentially called the humerus. And in fact, this is actually one part of what we will call the shoulder joint. Now, even though you might think, well, there's a connection here between the scapula and the thoracic cage, there really isn't. So there is actually no articulation here between the scapula and the thoracic cage. It's just kind of held there by ligaments and muscles and things like that. But if we're looking at the anterior side, and once again, this is the right scapula, then you'll notice that there are two major features that you see on the anterior side of the scapula. The first one is actually a depression here called the subscapular fossa. This actually is an area where a muscle, which is similar in name called the subscapularis, is attached. Also on the anterior side, you have the coracoid process. And it's important on any kind of test that you watch the spelling. Because as you'll find out, if you have started learning the skeletal system, there are some very closely similar names that look very similar in spelling. This coracoid process is actually one of the structures that certain shoulder ligaments actually attach to. Now, if we look on the posterior side, essentially, of this scapula, you'll notice several features as well. One very prominent feature that you can see here is what's called the spine of the scapula. This is actually a major division point between two fossas. One here on the inferior side called the infraspinus fossa. And there is actually a muscle there as well. And then the supraspinus fossa. The muscles in these two areas, along with the one on the anterior side, actually make up a group of muscles called the rotator cuff, which is important actually for helping you to rotate your shoulders, especially if you're, say, a baseball player and you're throwing a pitch or something like that. Still looking at the posterior side, however, at the end of the spine of the scapula, you've got this kind of flared portion here called the acromion. And if you remember from much earlier, the acromion is the part that's actually going to attach to the clavicle. And there are some ligaments that attach the clavicle, essentially, to the acromion as well. Now, one thing you have to keep in mind is, once again, orientation. And you'll notice that the last feature that I really wanted to mention today was a shallow depression. And this is actually on the lateral side of the scapula. And this is called the glenoid cavity. Now, the glenoid cavity doesn't look like much of a depression. It is pretty shallow. It's actually the part of the scapula that really is associated with the shoulder joint. And essentially, if you look at this here, you'll notice that there's a ball-shaped part of the humerus that actually fits in with that glenoid cavity. Because it is so shallow, there's not really a lot of protection for it, except through muscles that surround that area and also certain ligaments that also help to hold the shoulder joint together. Although that is still a pretty easily damaged joint, especially when we like to use a lot of movements. And so that essentially is a nice overview of the pectoral girdle. I hope you enjoyed this video. And so now, why don't you try to see if you can find these parts on your own. Thank you for your time.