Anatomy & physiology/My fantastic voyage - Essay Example

Maltose is the disaccharide formed. A small amount of the starch is digested in the mouth (Alcamo and Krumhardt, 2004). The food is mixed with mucous from the salivary glands. Mucous helps in the lubrication of the gastrointestinal tract. The food now in bolus form passes from the mouth into the esophagus. An important structure called epiglottis is located between the mouth and the esophagus. Epiglottis functions as a barrier to food entry into the trachea thus preventing choking. Once through the epiglottis, the next structure is the esophagus; 10 inches long.

Swallowing of food is assisted by peristalsis which is involuntary wavy muscle contractions in the gastrointestinal tract (Alcamo and Krumhardt, 2004). At the end of the esophagus, there is a food gate called upper esophageal sphincter. The sphincter opens to the stomach and allows the food bolus to enter stomach. Once the food enters the stomach, the upper esophageal sphincter closes to prevent the swallowed food from traveling back into the esophagus. The stomach is the next major structure.

The stomach resembles a sack and it is lined with mucosa. The mucosal lining of the stomach has numerous tubular gastric glands. Gastric pits are tiny gastric gland holes and they open to the mucosa surface. Gastric glands secrete gastric juices. The major components of the gastric juice include pepsinogen, hydrochloric acid, mucus and intrinsic factor. The secretion of the gastric juices begins way before the food bolus enters the stomach due to the parasympathetic stimulation of the stomach by impulses from the vagus nerve (Alcamo and Krumhardt, 2004).

The components of the food swallowed by the 55 year old man include starch (carbohydrates), fats, vegetables, alcohol and proteins. The food in the stomach is mixed with food enzymes and acids. The enzymes and acids assist in the breaking down of food into smaller digestible particles. Protein is the only food molecule that will be broken