(2.26)
In this section we’ll look at one branch of the subaclavian that’s important in the thorax, the internal thoracic artery. To look at it, we’ll put the first rib and the manubrium back in place. The subclavian artery arches over the upper surface of the first rib, passing behind the anterior scalene muscle. Before passing behind the anterior scalene, it gives off these branches, the thyro-cervical the vertebral, and this one, the internal thoracic.
The internal thoracic artery runs downward and forward over the dome of the pleura, and passes behind the first costal cartilage. To see where it goes, we’ll look at a dissection of the anterior chest wall by itself, seen from behind. Here are the two internal thoracic arteries.
After passing behind the first rib, which is here, each one runs down the inside of the chest wall, just lateral to the sternum, in front of the transversus thoracis muscle. Its branches supply the anterior chest wall. Its distal continuation, known as the superior epigastric artery, supplies the upper part of the anterior abdominal wall, as we’ll see in the next section.
Now we’ll return to the aorta. We’ve seen the arch; now we’ll look at the descending aorta in the thorax. To get a clear look at it, we’ll take the heart , and the arch of the aorta, out of the picture.
The descending aorta runs downwards in close company with the esophagus. The esophagus lies medial to it up here, in front of it down here. We’ll remove the esophagus.
On each side the descending aorta gives off this series of posterior intercostal arteries, one for each of the intercostal spaces except the first two. Each posterior intercostal artery passes along the deep aspect of an internal intercostal muscle, in company with an ...
(2.26)
In this section we’ll look at one branch of the subaclavian that’s important in the thorax, the internal thoracic artery. To look at it, we’ll put the first rib and the manubrium back in place. The subclavian artery arches over the upper surface of the first rib, passing behind the anterior scalene muscle. Before passing behind the anterior scalene, it gives off these branches, the thyro-cervical the vertebral, and this one, the internal thoracic.
The internal thoracic artery runs downward and forward over the dome of the pleura, and passes behind the first costal cartilage. To see where it goes, we’ll look at a dissection of the anterior chest wall by itself, seen from behind. Here are the two internal thoracic arteries.
After passing behind the first rib, which is here, each one runs down the inside of the chest wall, just lateral to the sternum, in front of the transversus thoracis muscle. Its branches supply the anterior chest wall. Its distal continuation, known as the superior epigastric artery, supplies the upper part of the anterior abdominal wall, as we’ll see in the next section.
Now we’ll return to the aorta. We’ve seen the arch; now we’ll look at the descending aorta in the thorax. To get a clear look at it, we’ll take the heart , and the arch of the aorta, out of the picture.
The descending aorta runs downwards in close company with the esophagus. The esophagus lies medial to it up here, in front of it down here. We’ll remove the esophagus.
On each side the descending aorta gives off this series of posterior intercostal arteries, one for each of the intercostal spaces except the first two. Each posterior intercostal artery passes along the deep aspect of an internal intercostal muscle, in company with an intercostal vein and nerve. It stays close to the lower border of the rib, in this groove that we saw earlier.