Final answer:
The multiple circular folds in the intestinal lining are called plicae circulares, which aid in nutrient absorption by slowing the movement of chyme.
Step-by-step explanation:
The intestinal lining that is arranged into multiple circular folds is called plicae circulares. These are deep ridges in the mucosa and submucosa that begin near the proximal part of the duodenum and end near the middle of the ileum. These circular folds facilitate the absorption of nutrients by causing the chyme to spiral through the small intestine, which slows its movement and provides more time for nutrient absorption. Within these folds are the villi and microvilli, which also play a critical role in increasing surface area for absorption.