The digestion of food begins in the mouth by the action of the enzyme secreted by the glands. This enzyme begins the breakdown of starch. When you swallow, the bolus of food moves down the by rhythmic muscular contractions called peristalsis. In the stomach, the action of the enzyme and hydrochloric acid aid in the breakdown of . After leaving the stomach, the acidic mixture of partially digested food, called chyme, enters the first part of the small intestine, the duodenum. Here digestion is completed by the action of enzymes from the pancreas, and bile, which is produced by the liver. Bile aids in the breakdown of . The pancreas contributes bicarbonate ions to neutralize the acidic chyme, as well as digestive enzymes (proteases, amylase, and lipase). In the small intestine, numerous tiny projections called are responsible for absorption of nutrients. The primary function of the large intestine is to reabsorb .

Amylase; salivary; esophagus; pepsin; proteins; fats; villi.

Explanation:

Living system can be defined as the internal systems of organisms and how materials circulate within organisms. Also, living systems comprises of the following components; cells, organs, muscle, tissues, blood, etc.

Some examples of living systems in organisms are respiratory system, nervous system, circulatory system, and digestive system.

The digestion of food begins in the mouth by the action of the enzyme amylase secreted by the salivary glands. This enzyme begins the breakdown of starch. When you swallow, the bolus of food moves down the esophagus by rhythmic muscular contractions called peristalsis. In the stomach, the action of the enzyme pepsin and hydrochloric acid aid in the breakdown of proteins. After leaving the stomach, the acidic mixture of partially digested food, called chyme, enters the first part of the small intestine, the duodenum. Here digestion is completed by the action of enzymes from the pancreas, and bile, which is produced by the liver. Bile aids in the breakdown of fats. The pancreas contributes bicarbonate ions to neutralize the acidic chyme, as well as digestive enzymes (proteases, amylase, and lipase). In the small intestine, numerous tiny projections called villi are responsible for absorption of nutrients. The primary function of the large intestine is to reabsorb