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Multiple Choice
The velocity of blood flow is ________.
A
highest in the aorta and lowest in the capillaries
B
equal throughout all types of blood vessels
C
highest in the veins and lowest in the arteries
D
highest in the capillaries and lowest in the veins
Verified step by step guidance
1
Understand the relationship between blood vessel structure and blood flow velocity: Blood flow velocity is influenced by the diameter and cross-sectional area of the blood vessels. Larger vessels like the aorta have a smaller total cross-sectional area compared to capillaries, which have a much larger total cross-sectional area due to their abundance.
Recall the principle of blood flow dynamics: Blood flow velocity is highest in vessels with a smaller total cross-sectional area (like the aorta) and lowest in vessels with a larger total cross-sectional area (like capillaries). This is because the same volume of blood must pass through all parts of the circulatory system, and the velocity adjusts accordingly.
Consider the role of capillaries: Capillaries are the site of nutrient and gas exchange, and their large total cross-sectional area slows down blood flow to allow sufficient time for these exchanges to occur.
Eliminate incorrect options: The velocity of blood flow is not equal throughout all types of blood vessels, nor is it highest in the veins or capillaries. These options contradict the principles of blood flow dynamics.
Select the correct answer: Based on the understanding of blood flow dynamics, the velocity of blood flow is highest in the aorta and lowest in the capillaries.