 quick video to demonstrate the facial deep facial relationships in the pectoral region and in the axilla. So we have a deep fascia stretching from the clavicle all the way to the axillary fascia and that composite fascia is referred to as the clavipectoral fascia. The clavipectoral fascia is divided into four components. The first component is the one which covers the subclavius muscle which is a small muscle located under the clavicle here but we cannot see it. Then that fascia continues down and it becomes known as the costocorochoid membrane. This costocorochoid membrane is the flow of the delto pectoral triangle which I am going to demonstrate just now and then as this fascia continues further down it splits to enclose this muscle here that we see in front of us. This is the pectoralis minor so it becomes the pectoralis minor fascia. It encloses the pectoralis minor both anteriorly and posteriorly and then the fascia continues further down and we can see remnant of that fascia here. It becomes known as the suspensory ligament of axilla and this suspensory ligament of axilla gets attached to the deep surface of the axillary fascia and it is this suspensory ligament of axilla which is responsible for producing the hollow of the axilla when we abduct our arm and this hollow disappears when we abduct our arm. So these are the four components of the clavipectoral fascia namely the subclavius fascia, costocorochoid membrane, pectoralis minor fascia and the suspensory ligament of axilla. Having said that now let us focus on just the costocorochoid membrane part of it. This space that we see here in front of us this is referred to as the delto pectoral triangle or the clavipectoral triangle. This is bounded by the deltoid muscle posteriorly, pectoralis major anteriorly and superiorly by the clavicle and this triangle the floor of this triangle is formed by the costocorochoid membrane and this costocorochoid membrane is pierced by four important structures. One of them is this vein that we can see here. This is a very important the most important superficial vein of the arm upper limb which is used for various surgical purposes. This is the cephalic vein initially it runs in the delto pectoral group in the group between the deltoid and the pectoralis major and then it goes into the delto pectoral triangle and it then pierces the costocorochoid membrane as we can see here piercing and it enters into the axilla and drains into the axillary vein. So that is one important structure which pierces the costocorochoid membrane. The second important structure which pierces the costocorochoid membrane is this structure which I have lifted up here. This is the lateral pectoral nerve. This comes out from the brachial plexus from the lateral cord and it supplies the pectoralis major muscle as we can see it doing here. The third structure which pierces the costocorochoid membrane is this. This is the thoracoachromial artery. This is a branch from the second part of the axillary artery and this has got four sub branches and we can see many of those branches. One of them is the pectoral branch which is supplying the pectoralis major. The other one is the deltoid branch which supplies the deltoid muscle. This is the deltoid branch which has been separated. The third branch is the clavicular branch and the fourth branch is the acromial branch. So these are the four branches of the thoracoachromial artery. So these are the three structures which pierce the costocorochoid membrane and finally there are some lymphatics which also pierce the costocorochoid membrane. These lymphatics come from the inter pectoral nodes. The nodes which are located between the pectoralis major and the pectoralis minor which are also referred to as the daughter nodes. And these pierce through the costocorochoid membrane and they drain into the central group of axillary lymph nodes. So that is about the costocorochoid membrane, the deltoid pectoral triangle, the cephalic vein and the structures piercing and if you have any questions or comments please put them in the comment section below. Thank you.