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Inglés, Reading

8° Básico

The digestive system

Our body needs to obtain energy to live and perform an assortment of activities everyday. The digestive system has the essential task of processing all of the food we intake, converting it chemically to only absorb the substances the body needs, due to the functions performed by each of its organs.

Mouth digestion

Food is ingested and then broken down within the mouth cavity. Food is blended with saliva, going through its first chemical transformation.

The mouth is the food receptor: its walls are soft and have saliva secreting glands, which allow the moisturizing of food, easing its latter advance through the esophagus. Saliva is composed of 99.5% water and 0.5% electrolytes, vitamins, enzymes and cellular material.

Teeth cut and grind food and the tongues function is to mix the food within the mouth (mechanical digestion). A form of chemical digestion also takes place here thanks to the action of salivary enzymes (in glucids such as starch).

The mouth digestions main function is to transform the food substances onto a soft mass called food bolus, which will then continue its journey to the esophagus and then to the stomach.

The transformation of foods

Food continues its trip through the digestive tube, from the larynx towards the esophagus and then to the stomach, where it is blended with gastric juices and is now dubbed chyme.

Next, the small intestine receives the already processed food, enabling the addition of pancreatic juices, bile and juices from the intestinal wall. At this stage of the digestive process, food is converted into a mass called chyle, which is made up of amino acids, glucose, fatty acids and glycerin
The body absorbs these nutrients through the intestinal walls, discarding useless substances.

The leftovers reach the large intestine, where the final assimilation of the body takes place: mineral salts and water are absorbed. The leftovers or feces are disposed of through the anus.

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