Arteries – Blood vessels and blood circulation

00:01 returns to the heart.

00:01 So let’s talk about the arteries. These are the vessels that convey oxygenated blood away from the heart – away from the left ventricle – eventually to the body tissues to the capillaries. They start out big and they keep bifurcating or dividing into smaller and smaller vessels, eventually the arterioles, as they get further away from the heart until eventually the arterioles connect to the capillaries where the blood gives off its oxygen and nutrients and collects waste products.

00:40 The circulation usually is drawn and with the arterial system in red and the venous system in blue.

00:51 The largest and most important blood vessel in the body is the aorta. This is the large blood vessel that leaves the heart just above the aortic valve and supplies blood to each of the branching arteries throughout the body. And we’re going to be looking at each of those branching arteries in a minute.

01:13 The first branches off the aorta are the coronary arteries of course because the heart has to have nourishment in order to keep pumping. Then one arrives at a large right-sided vessel called the right brachiocephalic artery which divides into the right subclavian and the right carotid. The right carotid goes up the right side of the neck supplying blood to the brain and the right subclavian supplies blood to the arm. We then arrive at the left carotid which supplies blood also to the brain and then the left subclavian which supplies blood to the left arm.

01:54 And here we see it in a little larger form. First you see the right and left coronary arteries coming off of the aorta just above the aortic valve. Then you come to the brachiocephalic which divides into the right subclavian and the right common carotid. And then you see the left common carotid and the left subclavian. So that, by the time the blood starts to go down into the descending aorta from the ascending aorta, you’ve already supplied the brain and you’ve supplied the arms and you’ve supplied the heart. And, of course, there are two carotids and two subclavians and only one brachiocephalic because that branches as I’ve just said into the right subclavian and the right common carotid.

02:43 Here we see an anatomically-correct diagram showing you blood vessels in the arm. And you can see in red is the brachial artery, which is a branch of the subclavian artery as it comes down into the arm. This diagram is right above the elbow. And you can see that the veins run very close to the arteries carrying blood back from the arm. There’s two brachials and eventually, down below at the wrist, we get into two radial arteries and then two ulnar arteries, one on each side. And then of course, there are the hand arteries and we’ll be showing you this in a moment.

03:25 Down below in the abdomen you can see that the aorta divides into a number of vessels that supply the bowel. So there is two mesenteric arteries – a superior and an inferior – and they supply blood to the bowel so that the bowel stays nourished and also so that we can absorb digested food substances which will be eventually delivered to all the cells of the body as nutrition.

03:56 And of course another major branch off the abdominal or lower aorta are the renal arteries or the kidney arteries. And these, of course, help to control the kidneys – our major sources of blood-pressure control and also fluid control. And we’ll be talking a lot more about them later on in this series.

04:16 Finally we arrive down at the leg. The aorta branches into two iliac arteries – one on each side – and then into two femoral arteries – one on each side – two popliteal arteries – one on each side – and a number of smaller foot arteries. So that on one side – let’s say the left – you come down from the aorta. The aorta branches into the iliac. Then the iliac becomes two components of the femoral artery, eventually, the popliteal artery, which is right behind the knee, and then down into the foot. And you can see here from this diagram very clearly that the veins follow the arteries in very, very close approximation.

04:57 Let’s talk a little bit about the capillaries because, of course, that’s where the oxygen