Activity 1
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How the food changes consistency and form
The processing of food in our body is one of the most complicated actions performed by the digestive system. The food undergoes a lot of changes from entering the mouth to becoming an excess waste, later on. In order to understand how it changes in consistency and form, we must first give a definition to the mechanisms behind it; mechanical and chemical digestion. Mechanical digestion entails physically chopping up food into tiny pieces in order to facilitate chemical digestion. On the other hand, chemical digestion further alters the molecular makeup of the consumed substances so that they may be absorbed into circulation.
Changes in consistency and form:
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Happens first in the mouth, the food intake will mix the saliva then undergo mechanical digestion making the bits smaller and will form the bolus. Enzymes in the saliva break down the starch in the formed bolus.
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The bolus will proceed in the esophagus to reach the stomach, the esophagus will have a series of wave-like muse contractions called peristalsis that will propel the bolus into the stomach.
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In the stomach, the bolus is broken down into much smaller, digestible bits by the stomach muscles as they churn and combine it with digestive secretions that include acids and enzymes. After 3 hours the bolus turns into a liquid called chyme.
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The chyme is then transported into segments of the small intestine for chemical digestion, bile is mixed in the duodenum, and a lot of deconstruction happens in the jejunum and ileum.
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The chyme travels on the surface full of micro projections called villi wherein the molecule absorption happens and the transference in the bloodstream.
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The leftover parts which primarily consist of fiber, water, and dead cells goes into the large intestine, which then drains the substance of its fluid via intestinal walls, the final form is now a soft mass called stool
In summary, food travels through a series of processes in which it is transformed into different forms with varying consistencies: bolus, chyme, and stool.
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How the body was able to absorb the nutrients from the foods we eat.
Similarly in the listed process in question number 1, the food is converted into different forms which allows the organs to get some of the nutrients. Most importantly the full absorption of nutrients happens during chemical digestion and in the small and large intestines. The finger-like projections of villi absorb most of the nutrients and redirect them to the capillary bed, lacteals, and organs; certain absorptions such as fatty acids go directly into the lacteals. The nutrients enter the bloodstream, the blood will then feed the organ and tissues with the appropriate nutrients it requires.