Activity 1. The Food Journey
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How the food changes consistency and form
- Food always enters our mouth first, where it is chewed, which results in mechanical digestion. The food is manipulated by the tongue, ground by the teeth, and mixed with saliva, and hydrolysis, or enzyme-assisted food breakdown, is present here. As a result, the food is reduced to a soft, flexible, easily swallowed mass because our primary goal is to create a bolus, a digested food sphere that can then be consumed and passed on into the esophagus. Food molecules start to dissolve in water in saliva, an important activity because salivary amylase and lingual lipase enzymes can only react with food molecules in a liquid medium and contribute to chemical digestion. The digested food then breaks down into smaller molecules such as the disaccharide maltose, the trisaccharide maltotriose, and short-chain glucose polymers known as α -dextrins.
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How the body was able to absorb the nutrients from the foods we eat.
- Swallowed food passes into the oropharynx and laryngopharynx after it has been broken down by the two enzymes salivary amylase and lingual lipase. These areas' muscular contractions aid in the passage of food into the esophagus and then into the stomach. The stomach is in control of churning, and several aspects of contraction affect the food and break it down. Hydrolysis, the enzyme-assisted breakdown of food, is also present here. The stomach's purpose is to produce chyme, a more fluid substance that we can pass on to our small intestines. Fatty acids, diglycerides, and monoglycerides were already broken down in the stomach, so the chyme entering the small intestines includes partially digested carbohydrates and proteins. The small intestine then plays a significant role in absorbing nutrients from the foods we eat because it has the main functions of segmentation in mixing chyme with digestive juices and bringing food into contact with mucosa for absorption, peristalsis propels chyme through the small intestine, completing digestion of carbohydrates, proteins, and lipids; begins and conducts digestion of nucleic acids; and absorbs approximately 90% of nutrients and water that pass through the digestive system. The large intestine also absorbs nutrients such as water, ions, and Vitamin K that our bodies needs.
Reference:
Tortora, G. J., & Derrickson, B. H. (2018). Principles of anatomy and physiology. John Wiley & Sons.