HUMAN NUTRITION

Detailed explanation-1: -The plicae circulares, villi, and microbilli are modifications of the small intestine for digestion and absorption. The plicae circulares are circular folds of the mucosa and submucosa. They force chyme to move spirally through the lumen. The villi are fingerlike projections of the mucosa.

Detailed explanation-2: -Circular folds These deep ridges in the mucosal lining triple the surface area of the absorptive mucosa in the intestinal wall. They also slow down the flow of chyme, as their shape causes it to travel in a spiral fashion rather than moving down the GI tract in a straight line (Welcome, 2018).

Detailed explanation-3: -Circular folds Their shape causes the chyme to spiral, rather than move in a straight line, through the small intestine. Spiraling slows the movement of chyme and provides the time needed for nutrients to be fully absorbed.

Detailed explanation-4: -Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract.

Detailed explanation-5: -Villi: The folds form numerous tiny projections which stick out into the open space inside your small intestine (or lumen), and are covered with cells that help absorb nutrients from the food that passes through.