MICROANATOMY

Detailed explanation-1: -Simple columnar epithelium: This type of epithelium is often specialized for absorption and usually has apical cilia or microvilli. These cells line your stomach and intestines.

Detailed explanation-2: -The mucosa, or mucous membrane layer, is the innermost tunic of the wall. It lines the lumen of the digestive tract. The mucosa consists of epithelium, an underlying loose connective tissue layer called lamina propria, and a thin layer of smooth muscle called the muscularis mucosa.

Detailed explanation-3: -The simple columnar epithelium is folded to form a number of invaginations, the crypts (also called crypts of Lieberkühn or intestinal glands). In the small intestine, several crypts surround the base of finger-like projections towering into gut lumen called villi.