Tenéis a vuestra disposición estos enlaces dirigidos a paginas mas o menos interactivas del Aparato digestivo: recursostic, dibujos, cerebriti, o arcade, e incluso un video. Lo podéis usar también para otros aparatos que iremos viendo....
DIGESTIVE
SYSTEM, PARTS
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DESCRIPTION
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PROCESSES (mechanical, chemical digestion, absorption…..)
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RESULTS
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MOUTH
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It is a cavity. The tongue is in it.
It is a muscular organ.
These are three pairs of salivary
glands which release saliva into the cavity.
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Teeth
are used to cut, crash and chew food into small pieces. The tongue mixes saliva with the
food. (Physical or mechanical
digestion) The saliva contains enzymes that breakdown the carbohydrates (a little chemical digestion begins).
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It is formed a bolus of food
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PHARYNX
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It is a channel, common to the
digestive and respiratory systems. Here food passes through from the mouth to
the esophagus. It has the epiglottis, which closes over the
respiratory tract to prevent food from obstructing it.
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Thanks to the peristaltic activity, the bolus of
food passes down the pharynx, through the esophagus.
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The
bolus of food goes down
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ESOPHAGUS
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It´s about 25
centimeters long.
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Food travels down it to the stomach thanks to the contraction movements of its walls (peristaltic
movements).
No digestion takes place here.
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The bolus of food goes down
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STOMACH
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It is a bag de 1´5 liter. It is connected to the esophagus and the
small intestine.
It has very
powerful muscles on its walls, and gastric
glands which secrete gastric juices.
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It stores the food and through peristaltic movements mixes the bolus of food with gastric juices and so the food is broken down into smaller particles. (chemical digestion continues).
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It forms a food paste. It is partially digested, semi-liquid.
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SMALL INTESTINE
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It is a very long tube, 6 meter long. Its walls have intestinal glands
which secrete intestinal juices.
Its walls
also have folds called intestinal villi.
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The majority of digestion
occurs here. (Chemical digestion continues).
These intestinal villi
have very fine blood vessels, the capillaries, through
which the nutrients obtained in digestion pass into the blood.
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Digestion finishes here.
Nutrients are
absorbed into the blood.
The majority of absorption occurs here
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ASSOCIATED GLANDS:
THE LIVER
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It produces bile, which is stored in the gall bladder. The bile enters
the duodenum where the digestion starts
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ASSOCIATED GLANDS:
THE PANCREAS
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This gland secretes pancreatic
juice. It also releases substances into the blood
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Pancreatic juice contains digestive enzymes that pass to the small intestine, and it helps in chemical
digestion
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Thanks
to the intestinal juices, the
bile and the pancreatic juices, the (chemical) digestion of food is
completed. It forms a paste, which contains nutrients. They will be absorbed
trough small intestine.
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LARGE INTESTINE
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It
is a wider tube than the small intestine of 1.5 meters long, with three parts: the cecum at the junction
with the small intestine, the colon, and the rectum.
The anus is the final part of the digestive
tract.
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In it water is
extracted from the residues undigested which form feces. The feces are stored in the rectum for a certain period.
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