Hello I am Jared. Welcome to FunScienceDemos. I have two friends with me today, Rachel C, and
my good friend the sea bass... well he is actually going to be my meal later on, but he has an important
purpose. Now the sea bass and Rachel... they may look pretty different to you, but believe it or
not they have a lot in common. It is their inside parts, that believe It or not, are pretty similar.
Scientists call these inside parts organs, and each organ is made of the same type of cell, and
each organ also does a very special job for the body - remember plants and animals are all made
of cells, and those cells need two things. They need oxygen from the air or the water, and they
need food. Rachel's lungs take oxygen from the air and put it into the blood. Rachel's stomach
and intestines takes food that she eats and puts that into the blood, and the heart is the thing
that moves that blood all throughout the body to all those cells. What about the sea bass? Let us zoom
in and take a closer look at his organs and see what they do. Now, remember this entire sea bass
is made of cells. This part right here is muscle, and that muscle is made of muscle, so in fact most
of the fish is muscle. So the question is how do all those muscle cells get food and oxygen? Well,
to answer that, we need to look at its organs. So let us pull the skin back so I can show you
the first organ right here. These are called the gills, and they actually take oxygen out
of the water and put it into the blood, so how does the fish then get the oxygen in the blood
to all the other cells? Well, I am going to show you - this tiny white thing right here at the end of
my pointer - that is actually the fish's heart. This red thing is the liver, this tiny white thing is
the two-chamber heart, and it pumps the blood to all the other cells. So, we took care of how the
oxygen gets to all the cells, but how does the food get to all the cells? Well, the fish will take food,
and through his mouth and that food will go into his stomach, and all this right here... well that is
his intestines. The food gets broken down in the stomach, and the intestines, and then gets passed
to the blood, then the heart pumps that blood to all the cells in the body, and just like us any
food that the fish can not use comes out the other end. We want to take a closer look at one more
special organ that only fish have - now scientists call that an adaptation. Any time animals have a
special organ, scientists call that an adaptation. Fish live in the water, and they need a special
organ to help them stay balanced and move easily in the water, and that special organ that only fish
have is called a swim bladder, because it helps them swim a whole lot better. So, now we are going
to zoom in and show you the swim bladder. We are going to show you where it is and what it does.
The swim bladder is the stretchy bag of skin right above the stomach and intestines, and it is usually
filled with a gas, which is oxygen. Watch what happens when I fill it with air with my straw.
The bag stretches out as the air fills it, and that helps the fish swim more easily and stay
balanced in the water. That is a pretty cool adaptation. It is really amazing if you think
about it - Rachel and the sea bass look so different on the outside, but when you
compare their inside parts, well a lot of them do the same thing - they take air and oxygen and
move that to all of the cells, but it is also amazing to think how Rachel and sea bass are
different. Fish live in the water and they have a streamlined body to help move through the
water, and they have gills to get oxygen out of the water, and they have the all-important swim
bladder. If you want to learn more about how the parts of living things work, check out our
.links in the video description. Science is so cool! The body is so cool, thanks for watching.