Hello. During this lecture we will discuss the vasculature of the upper limb. Our objectives here are to name the principle blood vessels of the upper extremity, to describe the difference between the superficial and deep venous drainage patterns, describe procedures commonly performed using the median cubital and subclavian veins, and name several of the pulse points. We begin with the origin of the blood supply to the upper extremity, which comes from the subclavian artery, which is a branch of the brachiocephalic trunk on the right and directly off of the aorta on the left. Subclavian artery arches across the neck, and then as it passes inferior to the clavicle, it becomes the axillary artery. To be clear, now this is the same artery just acquiring a different name in a different region. As the axillary artery descends the arm, it becomes the brachial artery until just past the elbow. Just past the elbow, the brachial artery divides into the radial artery, which follows down the lateral or radial side of the forearm, and the ulnar artery, which travels along the medial or ulnar border of the forearm. At the hand, these two arteries, the radial artery and ulnar artery, meet to form an anastomosis, which is just to say these vessels rejoin to form the palmar arterial arches, both the superficial and the deep arch. These palmar arterial arches give rise to the digital arteries which pass up along the borders of the digits to supply the fingers. This now is the posterior view of the wrist. What we're hoping to show here is the venous drainage of the upper extremity. What we see here is that there's also a venous arch on the dorsal surface of the hand, and this venous arch gives rise to a cephalic vein which travels up the radial border of the limb, and the basilic vein which travels up beyond that border. These vessels, the cephalic vein and the basilic vein, are joined at the elbow by the median cubital vein. You also see a number of other smaller veins, which I haven't labeled, and it turns out that there's a large range of smaller vessels that interconnect and provide the drainage. Now, what I've added here in this image, is to emphasize the fact that the cephalic and basilic veins are superficial veins, which is to say they are run in the subcutaneous tissue just beneath the skin, and they are not accompanied by arteries. The limbs have what's called a deep venous drainage pattern, and that deep venous drainage pattern follows the arteries. There will be a radial vein and an ulnar vein, and so on, and these veins accompany the artery. This image here shows, it happens to be a cross-section through the arm. We can see here the cephalic vein in the subcutaneous fat, and the basilic vein in the subcutaneous fat, and then indicated here the brachial artery and vein running together. The radial vein then provides the deep venous drainage of the extremity and the basilic and cephalic veins provide the superficial drainage. The brachial veins then eventually drain into the basilic vein, and the basilic vein then becomes the larger axillary vein, which in turn drains into the subclavian vein. It's this large size of the subclavian vein, which makes it attractive for introducing therapeutic drugs, particularly for cancer chemotherapy. If we think now about pulse points, there are many possible pulse points in the upper extremity. A common pulse point is at the elbow where the brachial artery comes to lie close to the biceps tendon. The ability to palpate or to feel the biceps tendon and just medial to that, one can locate a brachial pulse. At the wrist, you can identify both a radial and ulnar pulse. Now let's take too quick quiz here. Again, ungraded just for your own information to see how you're doing. Place these arteries in order from proximal to distal, meaning from close to the origin, to far away. We have axillary, brachial, radial, subclavian, and ulnar. If you placed them in this order, that's terrific. You recall that the main vessel that it shows the upper extremity is the subclavian artery, as it passes into the axilla, the armpit, it becomes the axillary artery, and then it passes into the arm or brachium, it becomes the brachial artery, and then distal to the elbow the brachial divides it into the radial and ulnar branches. Blood drawing is typically done in the cephalic vein, basilic vein, median cubital vein, subclavian vein. We said that the median cubital vein was an excellent place to draw blood because it's a place where the basilic vein and cephalic vein are interconnected, and since these superficial veins do not have accompanied arteries, it's a chance to draw blood without danger of puncturing an artery. Here's one true, false. The cephalic vein accompanies the cephalic artery. If you said false, that's great. You recall that the cephalic vein is part of the superficial venous drainage of the extremity, which does not have an accompanying vessel. The deep venous drainage follows the arteries. Brachial pulse is commonly assessed at or in? The axilla, the cubital fossa, or the wrist? The answer is cubital fossa. If you said that, that's good. You recall that's a convenient place to palpate the biceps tendon and remember that the brachial artery is just medial to that tendon. Placement of a catheter for central venous access for chemotherapy would be placed in the? Cephalic vein, basilic vein, median cubital vein, subclavian vein. If you said subclavian vein, that's good. You recall that it's a large vein and these feed compounds can cause damage to smaller vessels, so getting the chemotherapy into a large vessel is an effective way of distributing it to the body without damaging the vessel that you've catheterized. Thank you. We'll see you soon.
