Unit 15 The Digestive System Part 1

Unit 15   The Digestive System   Part 1


Unit 15 is the digestive system. Most of us have no
difficulty eating our way through a large meal like this. Our digestive system
works very efficiently to digest, and then absorb as
much of the food as possible. After dinner, our plates
might look like this, but what has happened during
the process of digestion is that the food
has been broken down into smaller and
smaller particles, that are then small and simple enough
to be absorbed into our body. Our cells require a constant
supply of nutrients and energy, and so we get those nutrients
and that energy, ultimately, from our food– from
the carbohydrates, the proteins, the
nucleotides, et cetera, that make up the food that we eat. The digestive system ultimately
ingests food, digests it, and absorbs the end
products of digestion, and then eliminates the waste. The digestive system is made
up of two major components– the digestive tract, and
then accessory organs. Looking at our digestive
system, the digestive tract is the canal that
extends from our mouth all the way down to our anus. Ultimately, you can kind
of think of our body as a big long tube, where we
have food come in one end, and then waste leave
out the other end. All throughout that
system, we have the breakdown of
that food, and then the absorption of the
nutrients, as we just mentioned. The digestive, or GI
tract, starts at the mouth. It then extends
back to the pharynx at the back of the
mouth, which runs down through the diaphragm
to the stomach. The stomach then empties into
the small intestine, which then empties into
the large intestine, and the large intestine
ends at the rectum. And then the anus is
where the excrement is released from at the end of
the processes that break down the food. Ultimately, this is the GI
tract– the digestive tract. Accessory organs, or
organs that are involved in the digestive
process– but are not part of the tract itself–
so they will release chemicals into the tract in
order to digest food, but the food does not travel
directly through them. These include the salivary
glands in the mouth, the liver, the gall bladder,
and the pancreas– which is actually behind the
stomach in the image shown here. These are all accessory
organs, as mentioned, because they release chemicals
into the digestive track. And we will look at
those a little bit later on in this unit.

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1 thought on “Unit 15 The Digestive System Part 1

  1. would you put the written part of your video here too so that we can study what you said when we can not listen to it? thx

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