Video Transcript
Why do arteries have thick,
muscular walls containing elastic fibers? (A) To allow the transport of
substances to other cells. (B) To prevent the backflow of
blood. (C) To prevent oxygen from being
lost from the blood. (D) To help them carry blood at low
pressure. Or (E) to help them carry blood at
high pressure.
You may recall that when blood is
pumped out of the heart, it leaves through the arteries. Let’s have a look at a cross
section through an artery. We can see that the artery has a
narrow lumen. This is the cylindrical space
through which the blood flows. It also has a thick wall, which is
composed of smooth muscle and elastic fibers. But why does the artery have these
properties?
Because blood flowing out of the
heart has to be transported all around the body, it must be under high pressure. Arteries must therefore be well
adapted to withstand and maintain this pressure as the blood moves through them. If they weren’t, the arteries would
either burst or the blood flowing through them would stop moving before it reached
all the parts of the body that required it.
We have therefore determined that
the correct answer is (E). Arteries have thick, muscular walls
containing elastic fibers to help them carry blood at high pressure.
