Aorta forms the main artery carrying blood away from the heart to the remaining parts of the body. It is through the aortic valve that the blood leaves the heart. Then, it travels through the aorta, producing a curve allowing other main arteries to supply oxygen-rich blood to the brain and other parts of the body. It has three main layers – intima (inner layer), media (middle layer), adventitia (outer layer).
Aorta has different sections – aortic arch, ascending aorta, descending aorta and the abdominal aorta. The section which is closest to the heart is the ascending aorta, hence it constitutes the upward part of the arch. On the other hand, the descending aorta is the downward part of the arch.
The main differing factor between ascending and descending aorta is that the ascending aorta forms the upper section of the arch and is the closest section of the aorta to the heart. The descending aorta constitutes the downward part of the arch, connecting to a mesh of arteries, supplying almost the entire body with oxygenated blood.
Ascending Aorta
- It originates from the upper terminal of the left ventricle, and continues as an arch of aorta at the sternal angle
- Its length is about 5 cm with a diameter of close to 3 cm. They are enclosed completely in the pericardium
- It develops from the truncus arteriosus after its separation by the spiral septum
Descending Aorta
- It is the part of the thoracic aorta that is contained in the posterior mediastinum
- It takes origin with the lower periphery of the T4 vertebra in accordance with the aortic arch, and ends anterior to the lower periphery of the T12 vertebra inside the aortic hiatus
- Initially, it begins to the left of the vertebral column however, it arrives at the midline as they descend
Key Difference between Ascending and Descending Aorta
The table below depicts the difference between Ascending and Descending Aorta.
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First part of the aorta beginning at the aortic valve |
Forms the third section of the aorta spreading across T4 to T12 becoming the abdominal aorta, contained in posterior mediastinum |
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It begins distal to the sinotubular junction extending to just before the ostium of the brachiocephalic artery |
It begins just distal to the isthmus extending to the diaphragm. Through the aortic hiatus, it exits the thorax in the diaphragm |
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Two coronary arteries |
Oesophageal arteries, pericardial arteries, bronchial arteries |
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Develops from the truncus arteriosus after its partition by the spiral septum |
Most of it is created through the combination of the primitive dorsal aortae |
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Providing the heart with blood |
Supplying blood to ribs and a few structures in the chest |
You read some differences between Ascending and Descending Aorta. For more such articles, visit us at BYJU’S NEET.
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