- First, the food enters the mouth, where it is mechanically digested into small particles via mastication, or chewing. During this process, it is mixed with saliva that contains salivary amylase that serves as the first step of chemical digestion. The chewed-up food is now called bolus. This bolus is then swallowed, and is transported to the stomach via the esophagus. The stomach is a reservoir of gastric juices that are very acidic. From here, the bolus gets converted into chyme. This chyme enters the small intestine via the pyloric sphincter, into the duodenum. From here, the small intestines continue to mechanically and chemically digest the chyme, absorbing all the nutrients the body needs to function. After all of this, the chyme is now feces, and enters the large intestine, where excess water is absorbed, as well as any residual digestible material produced by intestinal flora get absorbed as well, eventually reaching the rectum, and eventually, the anus, where the wastes get expelled from the body.
- The mucosa of the small intestine has many folds and finger-like projections called villi that are lined with simple columnar epithelium that contain microvilli. The purpose of this is to increase the surface area of the small intestine so that it can greatly absorb the nutrients coming from the chyme. Enzymes are also secreted by the duodenum and the pancreas to break the long-chain polymers into its simpler monomer forms that are better absorbed by the small body.
Activity 1. The Food Journey
TUMALIUAN, ALEXANDER PAUL V.
The due date for posting to this forum was Thursday, 30 November 2023, 11:59 PM.