Cells tissues and organs (Biology GCSE)




Uploaded by freeeschool on 04.09.2012

Transcript:
GCSE Biology – Cells, Tissues and Organs
Hello! Welcome and in this video, we are going to look at cells, tissues and organs and how
they all relate to each other.
To start us off, we’ve picked an organ that’s quite common to look at. We are looking at
the stomach and the stomach is made up of various different parts and various different
cells. It starts off over here on the left hand side. We have the muscle cells and these
are important because the stomach has to move around and churn up and help to digest the
food and the muscle helps to do that. You can’t have just one cell by itself; you
have to have many working together. You noticed that the cells fit together nicely and when
they fit together, they can all contract and work together and that contraction, as they
work together helps to move the stomach and helps to churn up the food. Individual muscle
cells make muscle tissue and that muscle tissue is found in the walls of the stomach.
The other type of cell that we have in here is called epithelial tissue and this provides
a kind of covering for the outside of the stomach. It is just outside the muscle there.
It is a kind of boundary between one organ and the other. Again, one cell by itself can’t
do very much but if we get lots of them joined up and again, notice how they are made to
fit together quite nicely; a bit like paving slabs. We get lots of them together and they
can make a nice covering. Also notice how the structure of the cell is very well adapted
to its function. They are quite wide and flat and that helps to provide a nice covering.
So we have epithelial cells and together, they make epithelial tissue which provides
the boundary between one organ and the next.
The last one down here that I have are what we call glandular cells or cells that produce
glandular tissue, again, this can’t work with just two or three together. You need
many more and so many together, working together make the glandular tissue to produce these
special chemicals that are used to produce to help in digestion. In actual fact, the
kinds of substances made by this tissue, they make enzymes to help digest your food.
Here, we have three different types of tissue working together and they all work together
in this particular structure, the stomach and they work together to make what we call
the organ. So you can see that the way these cells, tissues and organs are related. The
cells are individual units. They join together to make the tissue and the different tissues
join together to make organs.
As a summary, over here, we have cells as individual units. They join together to make
tissues. Tissues can join together to make organs and if we take it two steps further,
organs can join together to make organ systems and they can join together to make the actual
living organism. So just a few examples here. We talked about muscle or muscle tissue. Muscle
cells can make muscle tissue for various parts of the body and one other example is the heart.
The heart joins together with other organs, for example: veins, arteries and so on to
make the circulatory system which has the job of transporting blood around the body.
We have down here the nerves that make nervous tissue and an organ that has nervous tissue
is the brain which makes the nervous system. That again, can contribute to the organism.
Another organ here is the stomach that we talked about which we said was made of muscle
glandular, the kind of tissue that we talked about. Another type of cell is fat and it
makes fat tissue and that can contribute to other organs in the body.
The key thing that you need to know for this is how cells, tissues and organs relate to
each other and how they can join to make a whole system.
[end of audio – 04:36] GCSE Biology – Cells, Tissues and Organs
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