Axillary Artery – Overview of Arterial Supply to Upper Limb

00:00 So let’s look at the axillary artery. Remember, this is a right shoulder joint. We can see we’ve got pectoralis minor in a position here.

00:12 We can see we’ve got the clavicle. We can see we’ve got the humerus. And we can see entering into the axilla is the axillary artery. Over on this side of the screen, we can see the first part of the axillary artery as it is passing deep to the clavicle. And we are going to look at the branches that are coming from it. So, the axillary artery can be divided into three parts. Between the lateral border of the rib 1 and the medial border of pectoralis minor, we have the first part. And coming away from the first part is the superior thoracic artery.

00:52 So here, we can see the lateral border of rib 1, we can see here. And the medial border of pectoralis minor, we have the first part of the axillary artery. And really, coming off this first part is just going to be one artery. And this is the superior thoracic artery.

01:14 Superior thoracic artery, as its names suggest, is going to supply the superior aspect of the chest wall. So it will supply the first and second intercostal spaces and also give blood supply to serratus anterior. If we then carry on passing down through the axilla, we can follow the axillary artery as it now runs deep to the pectoralis minor muscle.

01:41 And the second part conveniently gives off two arteries. This is the lateral thoracic artery. So we have the lateral thoracic artery and we can just about make that running underneath pectoralis minor here, the lateral thoracic artery. And as its name suggests, this supplies the lateral thoracic wall especially serratus anteriorly. But also coming from the second part, posterior to pectoralis minor, is the thoraco-acromial artery. In the diagram, we can see it’s just slightly above pectoralis minor, and that’s really for convenience or the diagram becomes very confused. We can see that just above here, but coming from the second part, we have the thoraco-acromial artery. The third part, we can see, is coming from below pectoralis minor. So as the axillary artery passes below pectoralis minor, this inferior or lateral border of pectoralis minor, we can see the axillary artery carries on.

02:46 And the axillary artery finishes as it passes alongside the inferior border of teres major where it then becomes the brachial artery. So as the axillary artery passes the inferior border of teres major, it becomes the brachial artery. But within these boundaries, the third part of the axillary artery gives rise to two circumflex humeral arteries. It gives rise to anterior and posterior circumflex humeral arteries. We can see these running around the surgical neck of the humerus here, and this will anastomose around the surgical neck of the humerus. And it also gives rise to the subscapular artery. And we can see the subscapular artery running down in this direction. It’s running down to supply the thoracic wall, but it also gives rise to the branches going back up here. And this is known as the circumflex scapular artery. We can see this running all the way over here in this direction.

03:46 And later on, we’ll see an important anastomosis of this artery around the scapula. But first of all, I just want to talk about the thoraco-acromial artery. This is an artery coming from the second part of the axillary artery deep to pectoralis minor. It is a short and wide artery that pierces the clavipectoral fascia, and it divides into four important branches.

04:14 We can see it’s coming off here. It’s very short. It’s quite wide, coming from the second part of the axillary artery. We can see we’ve got a clavicular branch, and if you remember looking at the clavicle in the first lecture, we had that nutrient foramen.

04:28 And this is where the clavicular branch passes in to supply the clavicle. We can see it then comes away and we have these pectoral branches that go and supply pectoralis minor and pectoralis major, the pectoralis muscles on the anterior chest. And we can see it then turns laterally and it goes towards the deltoid muscle. It has a deltoid branch, and it goes up towards the acromion, the acromial branch where it can form again numerous anastomosis around the scapula; so the thoraco-acromial artery coming off the axillary artery, coming from its second part. So now, let’s move down into the arm, and we can see on the diagrams here on the screen, we’ve got now the brachial artery. As the axillary artery pass the inferior border of teres major, it just became the brachial artery as it run in the brachium which is your arm. It runs down. And remember, it’s running alongside or adjacent to the median nerve, we can see running here. And here, we can see of a more anterior view close up with some of the muscles being dissected; we can see the brachial artery here running alongside the median nerve. And we can see various muscular branches going towards brachialis and biceps.