Difference between Aorta and Pulmonary Artery

By Jaxson

Main Difference

Both, aorta and pulmonary artery are arteries but the main difference between aorta and pulmonary artery is, aorta is responsible for carrying oxygenated blood to entire body. On the other hand, pulmonary artery is responsible for carrying deoxygenated blood to lungs for oxygenation.


Aorta is a distensible, elastic artery. Aorta expands when blood is pumped inside aorta from the left ventricle. During diastole, blood pressure is maintained due to this stretching which is caused by the pressure of blood, as during this time the aorta contracts passively. Aorta is much larger and has three arteries extending from it. It is basically the main trunk of series of those vessels which carry oxygenated blood to entire body tissues for their nourishment. The walls of aorta are thicker because it has to bear high pressure of blood inside it. If aorta would not have thick walls then it would not be able to handle the pressure and will eventually burst.. As it pumps blood through entire body, therefore it builds up high pressure as compared to pulmonary artery. Talking about structure of aorta, it is divided into five main sections.

  1. Aortic Root: It is the first section and it is the base of aorta which is connected to the heart’s pumping chamber. It produces two coronary artery which carry oxygenated blood to muscles of heart. These coronary arteries give rise to ascending aorta.
  2. Ascending aorta: This portion begins from the aortic root from where coronary arteries end. It ascend upward and forms arch of aorta. This is considered as the most vulnerable part of aorta because it has very little support from surrounding tissues and handle complete output volume.
  3. Arch of aorta: I is the curved section which gives rise to arteries which supply the upper body including head.
  4. Descending Aorta: Arch of aorta terminates into descending aorta which is responsible for supplying oxygenated blood to spinal cord.
  5. Thoracoabdominal aorta: It begins at diaphragm and end at celiac, visceral and superior mesenteric arteries.
  6. Abdominal aorta: It begins below renal arteries and ends at two iliac arteries. This section is responsible for supplying blood to kidneys.

Diseases of aorta are diagnosed mainly by MRI. Considering the fact that aorta is primary artery which is responsible for supplying oxygenated blood to rest of the body, any disease of aorta could prove fatal. Some of aortic diseases are, aortic dissection, aortic aneurysm, aortic inflammation, atherosclerosis and many more. Moreover, there is a complain of weak walls of aorta in various connective tissue disorders.Aorta mainly suffers from weakness due to disease occurring in it, this results in dilatation of walls of aorta giving rise to an aneurysm. This could also lead to split causing dissection of aorta. Some individuals could also result from hardening of walls of aorta which could obstruction.

Pulmonary Artery

Pulmonary artery carries deoxygenated blood to lungs where the blood is purified and oxygenated. Pulmonary artery is originated from pulmonary trunk in the right ventricle of heart. It is situated directly beneath aorta. Pulmonary artery has basically two parts. One part of pulmonary artery goes in the right lung and the other part branches to the left lung. Like all arteries, pulmonary artery also carries blood away from the heart. Usually arteries carry oxygenated blood but pulmonary artery is the only artery that carries deoxygenated blood from heart to lungs for oxygenation purpose. Pulmonary artery is divided into main section.

  1. Pulmonary Trunk: It is also known as main pulmonary artery or just pulmonary artery. It comes from the right ventricle and then it further divides into right and left pulmonary arteries.
  2. Right and Left Pulmonary Arteries: As stated earlier, right and left pulmonary arteries are derived from pulmonary trunk. They supply deoxygenated blood to left and right lungs.

Pulmonary artery disease are usually diagnosed by MRI scans or MRI. These diseases could be acute or chronic in nature. Where there obstruction in blood flow due to any cause, it could lead to pulmonary embolism and in acute form it could lead to disruption in blood supply to lungs. Pulmonary hypertension is chronic when poor circulation of blood is caused by high blood pressure. and an increase in arterial pressure.. This increase in arterial pressure could lead to damage to heart, liver and lungs. There are various factors which could lead to pulmonary hypertension like tightening of wall of pulmonary artery or due to atherosclerosis. Apart from theses diseases, various congenital anomalies like stenosis could also affect the pulmonary arteries. Pulmonary artery is a muscular artery.

Key Differences

  • Aorta carries oxygenated blood to entire body while on the other hand, pulmonary artery carries deoxygenated blood from heart to lungs for its purification and oxygenation.
  • Function of aorta is to carry oxygenated blood to body and function of pulmonary artery is to deliver blood to lungs for its oxygenation.
  • Aorta is situated on top of the heart while on the contrary, pulmonary artery is situated beneath the aorta.
  • Aorta is the part of systemic circulation while pulmonary artery is the part of pulmonary circulation along with right and left pulmonary arteries.
  • Aorta pumps blood through the entire body therefore walls of aorta are thicker as compared to that of pulmonary artery so that it could easily bear the high pressure of blood.
  • Aorta originated from the left ventricle and pulmonary artery originated from the pulmonary trunk at the right ventricle.
  • Aorta is divided into five parts which are as follows: aortic root, ascending aorta, arch of aorta, descending aorta and thoracoabdominal aorta. Pulmonary artery is divided into two section which are, pulmonary trunk and right and left pulmonary arteries.
  • Aorta could be affected by hardening of walls of aorta but pulmonary artery include hypertension and also congenital anomalies for instance, stenosis.

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