Video Transcript
What do we call the small hairlike
structures that absorb digested food? Is it teeth, capillaries, villi, or
arteries?
So let’s look at each one of these
in turn to see if we can find out which is the correct answer. Before we do this though, we have
to make sure we understand what the word “absorb” means. Absorb is to take in or soak up
something in the same way that a kitchen towel could be used to absorb some spilt
water.
Okay, so looking at our answers
now, starting with the teeth, do the teeth absorb digested food? Well, if we look at a tooth
closely, we can see that it is covered with a very hard material called enamel. Enamel covers the tooth and
protects the tooth. It is especially important in
protecting the layer just beneath it. This layer is much softer, and it
is called dentin. And it can be eaten away by
bacteria. Therefore, the teeth with their
hard outer coating are not there to absorb anything, but there to cut and grind the
food. That said, teeth cannot be the
answer to the question.
Now, let’s turn to capillaries. Capillaries are tiny, tiny blood
vessels that we have throughout our whole body. You sometimes see them in your eyes
when they’re bloodshot from being tired. But do capillaries absorb digested
food? Well, they absorb oxygen from the
lungs, but they don’t absorb digested food. So that’s not the right answer
either.
Now let’s look at the villi. The villi is in the small
intestine. If we were to take a piece of the
small intestine, cut it open, and look at the inside lining, we’d see villi, which
look like small hairlike structures. The villi play a vital role in
absorbing digested food. So this looks like it could be our
answer. But let’s look at the last one just
to make sure.
Finally, we have arteries. Arteries are oxygen-rich blood
vessels that carry blood to tissues in our body. Arteries, like veins, are the
largest blood vessels in the body, whereas capillaries are the smallest, rather like
a tree with all its many branches. The thickest ones like the trunk
and the large branches, they’re like arteries, whereas the smallest branches that
come off these are like capillaries. That said, the walls of arteries
are too thick to absorb anything. All the oxygen is absorbed in the
capillaries, and they certainly don’t absorb digested food. Therefore, arteries can’t be the
correct answer.
So the only answer to “What do we
call the small hairlike structures that absorb digested food?” must be villi.
