Welcome back to the second basic lecture in
During this lecture, we’re going to go into
a little more detail concerning the blood
vessels and how they function in the circulation.
You’ll remember from the last lecture that
we talked about the main classes of blood
vessels. That’s what we’re going to talk
about first: the artery system and the venous
system and the capillaries.
So here’s a little diagram that shows you.
We’ve seen this one before actually. It
shows you that the arteries start out large
and progressively become smaller eventually
ending in arterioles that are the major resistance
factor in the circulation. Then we arrive
at the capillaries where most of the nutrient
and waste exchange goes on with the cells
of the body. And then that blood collects
in small venules, eventually large veins and
returns to the heart.