21 dic. 2016

Digiere y respira

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....

PROCESSES (mechanical, chemical digestion, absorption…..)
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.
 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).
It is formed a bolus of food
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.
Thanks to the peristaltic activity, the bolus of food passes down the pharynx, through the esophagus.
The bolus of food goes down
It´s about 25 centimeters long.
Food travels down it to the stomach thanks to the contraction movements of its walls (peristaltic movements).
No digestion takes place here.
The bolus of food goes down
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.
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).
It forms a food paste. It is partially digested, semi-liquid.

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.
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.
Digestion finishes here.
Nutrients are absorbed into the blood.
The majority of absorption occurs here
This is the largest gland in the human body. It carries out important functions for the organism.
It produces bile, which is stored in the gall bladder. The bile enters the duodenum where the digestion starts
It is a compound which aids in digestion of lipids.
This gland secretes pancreatic juice. It also releases substances into the blood
Pancreatic juice contains digestive enzymes that pass to the small intestine, and it helps in chemical digestion
These enzymes help in the further breakdown of carbohydrates, proteins, and fats.
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.
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.
In it water is extracted from the residues undigested which form feces. The feces are stored in the rectum for a certain period.
And then feces are expelled through the anus. It is Egestion.

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