The digestive apparatus must like
assure the digestion or assimilation different foods.
The digestion consists of reducing all foods in elementary substances simpler, able to happen to the blood to be used by the organism:
• Is like
power plant (power paper)
• Is for forming the necessary materials for the construction of the cellular architecture (
As we already know, the
of the digestive apparatus is to assure the digestion. The assimilation of different foods is obtained by its degradation in simple elements: fatty acid lipids, glúcidos in simple sugars (bears) prótidos in amino acids.
The set of these transformations needs combined mechanical and chemical actions. The mechanical actions consist of movements of mixed (
) and peristálticos (internal) The chemical actions require to digestive enzymes (also called diastasas) Lipasas degrades lipids, glucidasas glúcidos and the proteases the proteins.
The digestion begins in the mouth. By the mastication, the teeth crush and divide - mechanical action the foods, facilitating the
with the enzyme to salivar, the ptialina (glucidasa) chemical action - Therefore, the saliva (1 l to 1. 5 ls per day)
sugars and dampens the mucosa. It transforms foods into
doughy nourishing skittle.
simple one via of step. The liquids descend by the effect of their own
. The solid foods are impelled by the peristálticos movements, towards the
, tensile cavity that performs 3
• gastric Motilidad, assuring the mixed one the foods that gives rise to the formation of quimo. This mechanical action is under the dependency of the parasimpático
• Degradation of foods, being responsible the gastric juice that forms from:
• Acid hydrochlorate,
• protective Mucus of the mucosa and.
• Pepsina, proteolytic enzyme.
2 ls of gastric juice per day. The secretion is regulated by the nerves vague (order
) and by the gastrina (hormonal order)
• Storage of foods:
stores foods and
quimo very progressively. The gastric evacuating becomes through píloro, in small amounts. This progressive liberation in the duodeno allows to the
yield. The gastric evacuation needs
total of 5 to 6 hours, depending on the composition of the food.
of the digestion takes place in the duodeno and the rest of the
. The duodeno simultaneously receives the pancreáticos bile and enzymes. Let us see the paper of
one of them.
• the bile is secretada by the hepatocitos, it is stored in the
vesicle and it is excreted when the food ingestion takes place. It is constituted essentially by
. Its paper is the one of emulsionar greasy, transforming them into micro - drops that are more easily degradables by lipasas pancreáticas and
. The bile prepares, this way, the digestion of the greasy bodies.
• On the other hand alkaline his pH neutralizes the acidity of quimo gastric.
• the pancreático juice.
The páncreas are the main
of enzymes of the digestion as they are lipasas, colesterolesterasas, glucidasas (amylase) and several proteases: tripsina, quimotripsina carboxipeptidasas, elastasa.
The pancreático juice allows the degradation of the glúcidos ones and the prótidos ones. He is only the able one to degrade fats.
The enterocitos also synthesize enzymes of degradation like glucidasas, proteases and perhaps lipasas.
Let us remember that they produce secretina that triggers the pancreática secretion.
With the digestion one
obtained that the complex foods can be absorbed and be assimilated.
How takes place this absorption or assimilation?
of you fold covered by
vellosidades, the organism increases of considerable way the faying surface of the
mucosa with the food. The set of vellosidades - that constitute the absorption organ represents
surface of 250 m2. He is widely vascularizado and the cells of coating - enterocitos - is specialized in the absorption
• the absorption.
cross the enterocitos. Amino acids and bears are absorbed by the capillaries and follow the route sanguineous (vein carries towards the
Fatty acids and glicerol are absorbed, and once in the enterocito they become to recombine forming triglicéridos; these surrounded by proteins form then microscopic drops or quilomicrones that through the lymphatic route reaches the veins and the heart, without happening through the
Five to six hours after to have produced the ingestion of the food, quimo
reaches the heavy
. The cólico transit lasts 24 hours approximately.
The nonsecret colon no digestive enzyme nevertheless,
an important paper in the reabsorción of water and mineral salts. The
of quimo produces
content. The hardness of lees depends on the duration of the cólico transit.
is colonized by an important saprófita
that it acts on the glucídicos remainders of the digestion causing reactions of fermentation and on the protídicos remainders causing reactions of rotting. Both reactions are accompanied by
It is triggered when the rectal blister is full. The defecación needs the liberation the anal sphincter, constituted partly by fluted
fibers. It is the only element of the alimentary canal that
The fecal skittle, is compound of food remainders nondigested.
litiasis is defined as the presence of calculations in the
very frequent affection: 10%de the adults suffer it, reaching to 20% as of the 50 years. The litiasis is 2. 5 times more frequent in the woman who in the man. The
calculations are essentially colesterólicos (
90% of the cases in Europe)
of some foods (greasy, sauces, chocolate,
) that can give rise episodes of migraines and migrañas.
These crises disappear spontaneously after some hours,
they can end at serious complications:
• complete Obstruction by
calculation with hidrocolecistitis (considerable distension of the vesicle)
• acute Colecistitis (
• Litiasis of main the
route with ictericia and risk of sobreinfection (angiocólico)