In this video, Leslie will describe the scapula, the second part of the shoulder girdle. What are its parts? Let’s look into its different processes and fossae.
Transcript of Today’s Episode
In this video, I’m going to be talking about the structure of the scapula. More specifically inside this video, first I’m going to talk about the three borders and the three angles of the scapula. Then, I’m going to talk about the surfaces of the scapula, and lastly, the processes of the scapula.
Let’s get right into it.
Here, I’m looking at the scapula. We’ve looked at this in a previous video before. one thing I want to point out… The first thing I want to point out is that it kind of has a triangular shape. Like any triangle, it has three angles, and three borders. I want to point those out.
Let’s start with the angles first.
Then, of course, we have our three borders. Here, we have the medial border. Here, we have the lateral border, and here, we have the superior border.
So, the three angles are superior, inferior, and lateral or glenoid. And then, we have the medial, lateral and superior borders. Those are the three angles and borders.
All right, now, let’s get into some more fun details now.
We’re going to start by looking on the dorsal aspect of the scapula, so looking from the back. The first structure that I want to point out is a very obvious structure. That is the spine of the scapula. This structure here is the spine of the scapula.
Right here, we have the base of the spine, and then, the spine as it projects laterally, it’s going to end in this projection that’s called the acromion process. We’ve spoken about that process in the previous video, but I want to talk about it again.
That is the acromion process. That is the highest point. It comes from the word, ‘acropolis‘ in Greek. Acropolis is a city that’s high on an elevation. That’s what we’re referring to here. That’s the high point of the scapula. So, the spine, the base of the spine, and the acromion or the acromion process of the scapula.
Here, we have the spine as I mentioned. Conveniently, we have a space above and below that spine, and the space that’s above, the fossa that’s above, we’re going to call that the supraspinous fossa — ‘supra,’ for superior and ‘spinous‘ referring to the spine — supraspinous fossa, and beneath that, we’re going to have the infraspinous fossa — ‘infra‘ referring to inferior. Okay, so supraspinous fossa and infraspinous fossa.
If we were to flip this around and look at the anterior surface, we have this fossa here that we’re going to call the subscapular fossa. So, supraspinous fossa, infraspinous fossa, and the subscapula fossa.
One more projection that’s on the scapula, the anterior projection, that is the coracoid process. That’s going to be very significant. It looks like a bent finger, a bent thumb, to me at least. But, those are the processes. So, we have the coracoid process, and we have the acromion process.
Now, let’s talk about the last fossa. That’s called the glenoid fossa. We’ve spoken about that already and that is this structure right here, the glenoid fossa. You can see it looking from this side right here, the glenoid fossa.
Surrounding the glenoid fossa, we have a structure that I’m going to call the glenoid labrium, and with that, we have associated the glenoid ligament.
If you remember, this is where we have the glenohumeral joint. It’s where the head of the humerus is articulating with the scapula. What that labrium does is it allows for the cavity here to be deeper to allow for more rotation of the head of the humerus in that glenoid fossa.
There are two more structures that I want to point out here. You can’t see it very clearly up here, but right at the bottom of the glenoid fossa, we have a roughened tubercle that we call the infraglenoid tubercle, and then, at the top, we have the supraglenoid tubercle. You can also see that a little bit here. Right here, we have this roughened projection, the infraglenoid tubercle, and at the top, we’ll have the supraglenoid tubercle.
Those are all the structures that I want to point out for now. Let’s do a review quiz. As usual, if you would like to review with me and test yourself, you can turn the volume down and as I point things out, I want you to say what they are.
First, we’re going to start with the simple, here we have the superior angle, the inferior angle, and the lateral or glenoid angle. Then, we have the medial border, lateral border, and superior border.
Then, we have the spine of the scapula with the acromion process, and the base of the spine of the scapula. We have the supraspinous fossa, the infraspinous fossa, the subscapula fossa, and we have the glenoid fossa, or once again, this is the glenoid fossa.
We have the coracoid process and once again the acromion process.
That would be it. That’s pretty much it for this video. If you’d like to get more videos and other resources to help make Biology fun, visit the website at Interactive-Biology.com.
That’s it for this video. This is Leslie Samuel and I’ll see you in the next one.