Which structure has a normal pressure of 90-140 mmHg and is part of systemic circulation?

Which structure has a normal pressure of 90-140 mmHg and is part of systemic circulation?

• A. Aorta
• B. Pulmonary Artery
• C. Right Atrium
• D. Left Ventricle

Answer: (A)

This question tests the distinction between systemic and pulmonary pressures. In systemic circulation, arterial pressures are high because the arteries must push blood throughout the body. The aorta is the main vessel in this system, carrying blood ejected from the left ventricle under roughly 90–140 mmHg systolic pressure. In contrast, the pulmonary artery carries blood to the lungs under much lower pressures (systolic about 15–30 mmHg), and the right atrium sits at very low venous pressures (near 0–8 mmHg). The left ventricle does generate high pressure during systole as well, but it’s a heart chamber, not a vessel, and the question emphasizes a structure within systemic circulation that normally sits in that high-pressure range. Therefore, the aorta best fits the described pressure range.

This question tests the distinction between systemic and pulmonary pressures. In systemic circulation, arterial pressures are high because the arteries must push blood throughout the body. The aorta is the main vessel in this system, carrying blood ejected from the left ventricle under roughly 90–140 mmHg systolic pressure. In contrast, the pulmonary artery carries blood to the lungs under much lower pressures (systolic about 15–30 mmHg), and the right atrium sits at very low venous pressures (near 0–8 mmHg). The left ventricle does generate high pressure during systole as well, but it’s a heart chamber, not a vessel, and the question emphasizes a structure within systemic circulation that normally sits in that high-pressure range. Therefore, the aorta best fits the described pressure range.