Question

Why do veins have valves while arteries do not?

• A. Veins have thinner walls compared to arteries.
• B. Veins carry blood upwards.
• C. The pressure of blood flow in the veins is very low.
• D. Veins carry blood in both directions.

Answer 1

The correct option is C The pressure of blood flow in the veins is very low.

Veins carry blood from the body towards the heart. They are similar to arteries but not as strong or as thick.

The pumping force of the heart provides a strong pressure for the flow of the blood in the arteries. This does not allow for the blood to flow backwards but by the time the blood reaches the veins, most of the pumping force has dissipated and the veins experience a low pressure of blood flow.

This can lead to the blood flowing backwards. Hence, veins have valves that ensure that blood flows in only one direction.