Question

which blood vessel is under the greatest pressure?
a arteries
b veins
c aorta
d capillaries

Explanation:

To determine which blood vessel has the greatest pressure, we analyze each option:

• Option A (Arteries): Arteries carry blood away from the heart, but the aorta (a type of artery) is the main artery from the left ventricle. Arteries in general have high pressure, but the aorta has the highest among them.
• Option B (Veins): Veins carry blood back to the heart and have much lower pressure than arteries, often with valves to prevent backflow.
• Option C (Aorta): The aorta is the largest artery, directly receiving blood from the left ventricle of the heart, which pumps blood with great force. This makes the aorta experience the highest blood pressure as it distributes oxygen - rich blood to the body.
• Option D (Capillaries): Capillaries are tiny blood vessels where gas and nutrient exchange occurs. The pressure here is much lower than in arteries, especially the aorta, as the blood has already passed through arteries and the pressure drops as it moves into capillaries.

Among these, the aorta (Option C) is under the greatest pressure as it is the first vessel to receive blood from the powerful left ventricular contraction.

Answer:

C. Aorta