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Anatomy and branches of the thoracic (descending) aorta.
Hello everyone! This is Matt from Kenhub, and this tutorial will describe the thoracic aorta and its branches.
The aorta seen here, highlighted in green, is the largest blood vessel in the body, and almost all arteries stem from this vessel or from one of its branches.
Our focus in this video is a section of the aorta called the thoracic aorta or descending aorta and its branches. You can see the clear view of it here without any organs in the way. The terms thoracic aorta and descending aorta are used interchangeably, and they’re both perfectly acceptable.
Here’s an overview of the aorta so that you can find your bearings when we discuss the specifics of the thoracic aorta. After starting at the aortic valve, the ascending aorta winds towards the head, becomes the aortic arch or the transverse aorta as it makes a rainbow over the superior aspect of the heart, and then moves in an inferior direction through the chest and abdomen. At the left subclavian artery, it becomes the thoracic aorta.
After the thoracic aorta, comes the abdominal aorta and follows, then, the thoracoabdominal aorta which ends in its bifurcation into the left and right common iliac arteries.
Let’s now focus on the thoracic aorta. It begins at the level of the fourth thoracic vertebra and descends on the left side of the thoracic vertebrae from the fifth thoracic vertebra to the 12th thoracic vertebra. Running behind the base of the left lung and the pericardium, it enters the abdomen via the aortic hiatus of the diaphragm when it reaches the T12 vertebra.
The branches of the thoracic aorta include the bronchial arteries, the pericardial arteries, the superior phrenic arteries, the esophageal arteries, the posterior intercostals arteries, and the subcostal arteries.
Once again, those branches and the parts they supply: the bronchial which supplies the lungs, the pericardial which supplies the dorsal portion of the pericardium, the superior phrenic supporting the diaphragm and the adrenal glands, the esophageal supplying the (you guessed it!) the esophagus. The posterior intercostal, which you see here in green, supply the intercostal spaces and the subcostal, the flat abdominal wall muscles.