073 The Bones And Joints Of The Shoulder Girdle
Transcript of Today’s Episode
In this video, I’m going to be talking about the bones and joints of the shoulder girdle. Inside this video, most specifically, first I’m going to talk about the three bones of the shoulder girdle, and then, the three joints of the shoulder girdle.
Let’s get right into it.
What are the three bones of the shoulder girdle? I’m glad you asked.
The first one is the clavicle, then, we have the scapula. Lastly, the proximal end of the humerus, the proximal humerus. If I were to look at this picture right here, we can see those bones. The first one is the clavicle. This is also called the collar bone. Then, we have, on the posterior end, we have the scapula, and then, we have this bone which is the humerus.
But, for the shoulder girdle, we’re just talking about the proximal humerus, or the proximal end of the humerus. So, if I were to draw something around it, we’re talking about pretty much this structure here (forgive my terrible drawing but, you get the point). That is what we are referring to with the shoulder girdle — the clavicle, the scapula, and the proximal humerus.
Now, let’s talk about the three joints, these are the three points of articulation where one bone connects with the next.
Let’s talk about the first one which is the sternoclavicular joint. Just by the name of this joint, you should be able to determine what it connects to what. That is the joint, the connection between the sternum and the clavicle.
Here we have the sternum, but specifically, this top portion of the sternum we call the manubrium. We have the manubrium, and that connects with the clavicle. That joint right here is the sternoclavicular joint. You can see it also in this picture in a little more detail. Here is the clavicle, and this is the manubrium of the sternum. That is the sternoclavicular joint.
That joint, it is very significant because this is the one point of articulation that connects the upper extremities, so we’re dealing with the entire arm, that’s the one point where we have the upper extremities connecting to the trunk.
That sternoclavicular joint, very significant there. That’s the one point of bone-to-bone connection between the upper extremity and the trunk. That is between the clavicle and the manubrium of the sternum.
We have a number of ligaments involved that we’re not going to talk about in this video, but we are going to talk about in later video.
Let’s move on to the second which is the acromioclavicular joint. That is the joint where the clavicle, once again, is articulating with a structure on the scapula. That structure is called the acromion process, which is this superior elevation of the scapula. We have this projection that’s coming out in the superior aspect of the scapula. That is called the acromion process, which then makes sense for us to call it the acromioclavicular joint. Let me just draw an arrow right here… acromioclavicular joint, which is the second joint.
You can see that also here, the acromion and the clavicle forming the acromioclavicular joint.
If we look at the scapula once again, the glenoid fossa is the structure that we have under here. You can’t see it because it’s covered by a bunch of ligament, and the capsule, and all that jazz, but because we have the glenoid fossa, and the head of the humerus, the proximal humerus and the head right here, we call that the glenohumeral joint.
So, that’s pretty much it. Let’s do a quick review quiz. For these review quizzes, what you can do if you want to test yourself, you can turn down the volume, so that you don’t hear me speaking, but you just see what I’m doing, and you can say along with me what the different structures are.
First, the three bones of the shoulder girdle would be this bone, that is the (1) clavicle. Then, we have this bone, and that is the (2) scapula, and then, we have the (3) proximal humerus.
Those are the three bones and the three joints.
That’s pretty much it for this video. If you like to see more videos like this, you can visit the website at www.interactive-biology.com for more Biology videos, and all kinds of other resources to help make Biology fun.
This is Leslie Samuel. That’s it for this video, and I’ll see you in the next one.