Question

which blood vessel has the lowest velocity?
a artery
b vein
c capillary
d arteriole/ venule

Explanation:

To determine which blood vessel has the lowest velocity, we analyze the structure and function of each type:

• Arteries carry blood away from the heart under high pressure, so blood velocity is relatively high.
• Veins carry blood back to the heart, and while pressure is lower than in arteries, velocity is still higher than in capillaries.
• Capillaries are extremely narrow and have a vast total cross - sectional area. The slow velocity in capillaries allows for efficient exchange of nutrients, gases, and waste products between the blood and the surrounding tissues.
• Arterioles and venules are intermediate vessels between arteries/veins and capillaries, and their blood velocity is higher than that in capillaries.

Answer:

C. Capillary