In this episode, the origin, insertion and action of pectoralis minor is discussed. You will also learn that the pectoralis minor, though smaller than pectoralis major in size, functions to help in stabilizing the scapula. Watch to learn more.
Transcript of Today’s Episode
Hello and welcome to another episode of Interactive Biology TV where we’re making Biology fun. My name is Leslie Samuel and in this video, I’m going to be talking about the origin, insertion, and action of pectoralis minor.
Let’s get right into it.
All right. So, we have pectoralis minor. In order to see pectoralis minor, as I mentioned before in a previous video, you have to remove pectoralis major. You can see that’s already done. Then, you can see pectoralis minor.
Where does it originate?
Well, you can clearly see it here. Here, we have ribs three, four and five. You can see that it’s originating on the anterior surface of the ribs 3, 4, and 5, the third, the fourth and the fifth rib. You can see that it’s relatively near the costal cartilage. As you can see here, these are the costal cartilages of that rib, and that is where it’s originating. The anterior surface of ribs 3, 4, and 5.
Then, it comes up here and it extends and it inserts on the coracoid process of the scapula, but NOT the entire coracoid process, but the medial surface, the medial aspect of that coracoid process.
So, originates from the anterior surface of the ribs 3, 4, and 5; inserts on the medial portion or medial aspect of the coracoid process of the scapula.
What’s that going to do?
It’s smaller than pectoralis major, so it’s not going to have as great of an effect, but it still serve a very important role. Number one, it’s stabilizing the scapula. Just that muscle being there. Once the muscle is toned, and it’s doing what it’s supposed to do, it’s going to help in stabilizing that scapula because it’s attached there, and it’s attached on this end.
When that muscle contracts, when it’s contracting, what that’s going to do is it’s pulling against the coracoid process, but it’s pulling down just based on how the structure of that muscle is, so it’s pulling inferiorly and anteriorly. It’s bringing it down and forwards.
That’s the origin, insertion, and the action of pectoralis minor.
Let’s do a quick review. We’re dealing with pectoralis minor right now. I think I said pectoralis major but I meant to say minor.
The origin would be the anterior surfaces of ribs 3, 4, and 5. The insertion would be the medial aspect, or the medial surface of the coracoid process of the scapula. What it does, the action, it helps to stabilize the scapula and it pulls inferiorly and anteriorly against the thoracic wall. You can see that based on the structure of that muscle.
That’s pretty much it for this video. If you’d like more videos like this, you know what to do. Head on over to the website at interactive-biology.com.
This is Leslie Samuel, and I’ll see you in the next one.[table “” not found /]