This
higher magnification image shows the major features of the mucosa. (1)
The villi, seen
here in both longitudinal and cross section, consist of a core
of loose connective tissue, an extension of the lamina
propria, covered by a simple columnar epithelium.
(2) The crypts of Lieberkuhn
(intestinal glands),
seen here in
both longitudinal and cross section, are cylindrical
invaginations of the surface epithelium located at the bases of the villi.
They are lined by simple columnar epithelium and surrounded by the lamina
propria.