Question

question 21
1 pts
as blood travels from arteries to veins,
viscosity of blood changes.
pressure increases.
diameter of the blood vessels gets progressively smaller.
pressure decreases.
flow becomes turbulent.

Explanation:

Trace the systemic circulation pathway

As blood leaves the heart, it flows through the Systemic Circulation Pathway. It travels sequentially from the aorta to large arteries, arterioles, capillaries, venules, small veins, and finally back to the large venae cavae. This structural progression is classified under Blood Vessel Classification.

Analyze pressure changes along the pathway

Blood flows down a pressure gradient. This gradient is essential to overcome resistance and maintain forward flow. The highest pressure is found in the aorta and large arteries, while the lowest pressure is in the venae cavae and right atrium. Therefore, as blood travels from arteries to veins, the pressure must continuously decrease.

Evaluate the alternative options

• Viscosity changes: Blood viscosity remains relatively constant under normal physiological conditions.
• Pressure increases: This is incorrect because blood cannot flow from a lower pressure area to a higher pressure area without an external pump.
• Diameter gets progressively smaller: While vessel diameter decreases from arteries to capillaries, it increases again as capillaries merge into venules and veins.
• Flow becomes turbulent: Blood flow is typically laminar throughout most of the healthy cardiovascular system, especially in smaller vessels.

Answer:

• viscosity of blood changes.
• pressure increases.
• diameter of the blood vessels gets progressively smaller.
• pressure decreases. (Correct answer)
• flow becomes turbulent.