(2.40)
Next we'll take a look at the coronary arteries, which provide the vitally important blood supply to the heart itself. The detailed branching pattern of these vessels is highly variable: what we'll see here is just one example.
To see the coronary arteries, we'll look from above at a heart from which most of the epicardial fat has been removed. Here's the pulmonary trunk, here's the aorta. To see where the coronary arteries arise we've removed both atrial appendages. The left atrial appendage was here, the right atrial appendage was here.
Here's the right coronary artery. It arises from the right aortic sinus, which is here. The right coronary artery gives off this branch to the upper part of the right atrium, then runs downwards in the right atrio-ventricular groove, giving off branches to the right ventricle. The right coronary artery passes round to the underside of the heart: here it is again. Its terminal branch is the right interventricular artery.
Now we'll look at the left coronary artery: here it is. It arises behind the pulmonary trunk, from the left aortic sinus. The left coronary artery soon divides, giving off this circumflex branch, and several branches to the left ventricle, the longest of which is the left interventricular artery, also called the left anterior descending artery.
The circumflex branch of the left coronary artery runs around to the underside of the heart in the left atrioventricular groove, sending further branches to the left ventricle.
The blood that goes out by way of the coronary arteries returns, mainly, by way of a system of coronary veins, which join to form a large venous channel, the coronary sinus. As we saw earlier, the coronary sinus ends by entering the underside of the right atrium, here.
Here's the coronary sinus in ...
(2.40)
Next we'll take a look at the coronary arteries, which provide the vitally important blood supply to the heart itself. The detailed branching pattern of these vessels is highly variable: what we'll see here is just one example.
To see the coronary arteries, we'll look from above at a heart from which most of the epicardial fat has been removed. Here's the pulmonary trunk, here's the aorta. To see where the coronary arteries arise we've removed both atrial appendages. The left atrial appendage was here, the right atrial appendage was here.
Here's the right coronary artery. It arises from the right aortic sinus, which is here. The right coronary artery gives off this branch to the upper part of the right atrium, then runs downwards in the right atrio-ventricular groove, giving off branches to the right ventricle. The right coronary artery passes round to the underside of the heart: here it is again. Its terminal branch is the right interventricular artery.
Now we'll look at the left coronary artery: here it is. It arises behind the pulmonary trunk, from the left aortic sinus. The left coronary artery soon divides, giving off this circumflex branch, and several branches to the left ventricle, the longest of which is the left interventricular artery, also called the left anterior descending artery.
The circumflex branch of the left coronary artery runs around to the underside of the heart in the left atrioventricular groove, sending further branches to the left ventricle.
The blood that goes out by way of the coronary arteries returns, mainly, by way of a system of coronary veins, which join to form a large venous channel, the coronary sinus. As we saw earlier, the coronary sinus ends by entering the underside of the right atrium, here.
Here's the coronary sinus in an intact heart. The coronary sinus passes around the left atrioventricular groove to the underside of the heart. Its opening into the right atrium is just below and in front of the inferior vena cava. Coronary veins from the right side of the heart also empty into the coronary sinus.