What is the significance of the difference in thickness between the aorta and the pulmonary trunk?

Answer 1

To put it simply:

The blood in the aorta has to go all around the body. Blood in the pulmonary trunk has to go all around the lungs. The body is, obviously, larger than the lungs. This means blood going around the body needs to be "pushed" more. This is because there is more resistance. For example, it's harder to push a car for 1 mile, then it is to push it 1 metre.

Because the blood has to be pushed more, the heart (left ventricle) pumps it out at a higher pressure. Similarly, because the blood going around the lungs doesn't need to go so far, the heart (right ventricle) pumps it out at a lower pressure.

Because the blood in the aorta is at higher pressure than the pulmonary trunk, it needs to have thicker walls. For example a fire hose is thicker than a garden hose because it needs to transport water at a higher pressure.

The aorta contains large amount of smooth muscle and elastic tissue to help it cope with the high blood pressure.

Answer 2

The wall of the pulmonary artery is thicker because it carries blood to the lungs at a pressure of around 15mmHg while the vena cava returns blood to the heart at a pressure that is less than 8mmHg.

Answer 3

When the right ventricle contracts if forces blood into the pulmonary artery.

When the left ventricle contracts it forces blood into the aorta.

The right ventricle has a much thinner muscle wall so its contraction is weaker so less stretching force is exerted on the pulmonary artery so it does not need to be as thick.

Compared with the left ventricle which has thick strong walls that can contract powerfully which requires the aorta to be strong and thick to withstand the huge pressure increase when the left ventricle contracts to force blood out.

Answer 4

the walls of the aorta are generally thicker than the walls of the pulmonary artery. The wall thickness is usually a reaction to the pressure the cells of the vessel walls feel. In adults, the average pressure of the pulmonary artery is usually in the range of 20 mm of Mercury or so while the average in the aorta is around 80-100 (this is between the two numbers measured in your blood pressure)

Answer 5

The blood pressure passing through the pulmonary trunk from the right ventricle is significantly less than that of the blood pressure passing through the aorta form the left ventricle.

Answer 6

the aorta is much thicker and larger due to it's need to sustain higher pressures from the left ventricle.

Answer 7

The wall of the aorta is thicker because the blood that flows through it is at a higher pressure than the blood that flows through the pulmonary trunk.