Activity 1. The Food Journey
1. How the food changes consistency and form?
The changes in consistency and form of the food that we usually eat are processed by our digestive system. It is responsible for ingesting our food, breaking it into various nutrients that are required for our metabolic processes, and eliminating the wastes that cannot be utilized for other bodily functions. These include two types of digestion - mechanical and chemical.
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Mechanical digestion - physically breaks up food into little pieces to undergo chemical digestion.
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Chemical digestion - includes the use of digestive enzymes to break down the food's molecular structure so that it may be absorbed into the bloodstream.
The changes in consistency and form happen first in the mouth, the food intake will mix the saliva and then undergo mechanical digestion making the pieces smaller. These smaller pieces are mixed with saliva, forming a semi-solid paste called bolus that is easier to swallow. The bolus will travel through the esophagus to the stomach, where it will be propelled into the stomach by a series of wave-like muse contractions known as peristalsis. While in the stomach muscles, the bolus breaks it down into much smaller by stomach muscles as they churn and mix with digestive secretions that comprise acids and enzymes. After 3 hours, the bolus transforms into a liquid known as chyme.
The chyme is subsequently moved into the small intestine for chemical digestion, bile is mixed in the duodenum, and the jejunum and ileum do a significant amount of deconstruction. Then, the chyme moves over a surface covered with tiny projections known as villi, where molecules are absorbed and transferred into the bloodstream. After that, the remaining portions, which largely consist of fiber, water, and dead cells, pass through the large intestine, which subsequently drains the substance of its fluid along intestinal walls, resulting in a soft mass known as stool.
2. How the body was able to absorb the nutrients from the foods we eat?
The nutrients from the food we eat are absorbed through the body’s major digestive organ, which is the small intestine. As the largest portion of the alimentary tube, it is also the site of nutrient absorption into the bloodstream as it has an increased surface area for food absorption.
As the enzymes generated by the intestinal cells while the pancreas is transported to the duodenum by pancreatic ducts, and as bile (made by the liver) arrives through the bile duct, the small intestine is able to mix food with various digestive fluids and enzymes to push for further chemical digestion.
After that, the small intestine's walls allow nutrients and water to enter the bloodstream. The necessary nutrients will subsequently be fed to the organ and tissues through the blood.