circular folds (plicae circulares 環狀皺襞)– transverse ridges of mucosa and submucosavilli (絨毛)– finger-like projections of the mucosa covered with simple columnar epitheliummicrovilli(微絨毛)– further increase surface area for absorption
circular folds(plicae circulares環狀皺襞)–transverse ridges of mucosa and submucosavilli(絨毛)–finger-like projections of the mucosa covered with simple columnar epitheliummicrovilli(微絨毛)–further increase surface area for absorption<br>