Food Digestion Essay

Digestion can be described as food being broken down into its most basic and simple components so that we can absorb the nutrients to give us energy and nutrition. Digestion occurs in what is known as the gastrointestinal (GI) tract which consists of the mouth, esophagus, stomach, small intestine, large intestine (colon), and other important organs such as salivary glands, the liver, pancreas, and gallbladder.
Digestion first occurs with food entering the mouth. Food is usually comprised of three macronutrients: carbohydrates, fats (lipids), and proteins. In the mouth mechanical digestion via the grinding of food between teeth and movement of the tongue help mix the food with fluid excreted by salivary glands in the mouth known as saliva. Saliva helps makes the food moist and easier to digest and sallow. More importantly saliva helps start the chemical digestion of food in the mouth because it contains various enzymes which help catalyze and speed up the breakdown of the macronutrients into their simpler components. Carbohydrates are broken down via the enzyme salivary amylase. More specifically, amylase breaks down starch (a polysaccharide) which is made up of amylose and amylopectin into smaller starch units known as disaccharides and monosaccharides. Very …show more content…
Segmentation (the sloshing motion that mixes chyme with the enzymes and chemical fluids in the small intestine) and pendular movement (a constrictive wave that involves forward and reverse movements and enhances nutrient absorption) will be the main contributors to mechanical digestion in the small intestine. The liver, gallbladder, and pancreas secrete enzymes, fluids, and hormones which will help in the chemical digestion of the macronutrients into their simplest components so that they can be absorbed by the body via villi and microvilli (known as the brush border) and eventually circulated through the blood stream and lymph