Video Transcript
Which of the following correctly
compares veins and arteries? (A) Veins have a muscular wall to
carry blood at high pressure, and arteries have valves to prevent the backflow of
blood. (B) The majority of both arteries
and veins contain valves to prevent the backflow of blood. (C) Both arteries and veins have
thick, muscular walls to carry blood at high pressure. Or (D) arteries have a muscular
wall to carry blood at high pressure, and veins have valves to prevent the backflow
of blood.
To answer this question, let’s go
over what we know about arteries and veins and the roles they perform in the body’s
circulatory system.
Both arteries and veins are blood
vessels, but these two types of blood vessels perform two distinct functions. Arteries are responsible for
carrying blood away from the heart and to the other organs of the body, whereas
veins transport blood away from the body’s organs and back to the heart. As we know, the heart is
responsible for pumping blood throughout the body, delivering oxygen and nutrients
to the various organs and carrying away their waste products.
We mentioned earlier that arteries
are responsible for carrying blood away from the heart towards the other organs of
the body. Blood is pumped out of the heart at
high pressure. This high pressure helps to make
sure that blood doesn’t flow in the wrong direction. In order to withstand the high
pressure, arteries have thick, muscular walls.
Veins, on the other hand, carry
blood away from the organs of the body and back towards the heart. The blood pressure in veins is
low. To prevent blood from flowing in
the wrong direction, veins have special structures called valves at regular
intervals. These valves only allow blood to
flow in one direction. Since they do not have to withstand
high blood pressure, veins have thinner walls than arteries do.
With the information we now have,
we can identify that the correct answer is option (D). Arteries have a muscular wall to
carry blood at high pressure, and veins have valves to prevent the backflow of
blood.
