break down

Transcription

break down
DIGESTIVE SYSTEM
Food contains
complex
substances
which the body
breaks down
into simpler
particles.
• Every kind of food is digested
and absorbed as nutrients in the
digestive system in different
steps and digestive tracts.
• The nutriens are proteins,
carbohydrates, fats (lipids),
vitamins and minerals.
It takes place in
your digestive
tract which is like
a long tube
running from your
mouth to your
bottom (anus).
In your mouth the
teeth break down
food into chunks.
The salivary glands
produce saliva which
contains an enzyme
called ptyalin.
Ptyalin is an enzyme that
attacks the starch and
splits it in a more simple
sugar, into maltose.
.
The chewed and insalivated
food is called food bolus
No digestion occurs
here.
It links your throat
to the stomach.
The esophagus
pushes food into the
stomach through a
muscle movement
called peristalsis
It’s a muscular bag
that stores food
and breaks down
proteins.
The gastric glands
produce mucus,
hydrochloric acid
and enzymes.
Mucus protects the
stomach by the action of
hydrochloric acid and
pepsin.
The hydrochloric acid
kills a lot of bad bacteria
introduced with food .
The acid enviroment favors the
action of the pepsina.
It is an enzyme that cleaves
proteins into smaller molecules, the
peptones.
The food processed by the
stomach, which is called
chyme, is a dense and acid
mixture that is passed into
the bowel.
It works with the juice
coming from the liver,
pancreas and also the
enteric juice.
The enteric juice is rich
in enzymes, including
lactase, which breaks
down latose, the milk
sugar, into glucose and
galactose.
liver
pancreas
The pancreatic juice contains:
- sodium bicarbonate to neutralize
the acidity of the chyme;
The liver produces the
bile used to emulsify
lipids, that is to break
them into very small
droplets easier to
digest.
- trypsin, acts on proteins and
peptones supplementing the split into
amino-acids;
- maltase, splits maltose into two
glucose molecules;
- pancreatic lipase, that breaks down
lipids into glycerol and fatty acids.
At the end of the
digestion chyme is called
chyle.
The nutrients in the
chyle pass into the blood
through the intestine
walls and then they are
transported throughout
the body.
These projections
increase the surface
area for absorption
of water and
nutrients.
It accepts what
small intestine
doesn’t need or
can’t use and
later leaves the
body as waste.
Rectum is the last
part of the large
intestine and
stores feces
before it is
expelled.
Image credit:
• free clip Art by Phillip Martin
• Clker.com
• Wikipedia
• Wikimedia
• free images on Pixabay
• http://www.picgifs.com/clip-­‐art/entertainment/magic-­‐tricks/clip-­‐art-­‐magic-­‐tricks-­‐138804.jpg
• http://bit.ly/nutritionfactsupdates
• http://worldartsme.com/clip-­‐art-­‐push-­‐and-­‐pull-­‐clipart.html#
• http://www.clipartpanda.com
• http://cliparts.co
• http://it.123rf.com
• http://www.shutterstock.com
• Joaquin Moreno -­‐ https://www.flickr.com/photos/100902849@N05/11286341055
• http://www.deviantart.com/browse/all/resources/clipart/?q=cauldron