This view of the mucosa
shows: (1) villi, covered by a simple columnar epithelium consisting of goblet
cells and absorptive cells. Note the very cellular loose connective tissue,
part of the lamina propria, located within the villi and the nuclei of wandering
cells (lymphocytes and macrophages) between the columnar cells of the epithelium.
(2) intestinal
glands (crypts of Lieberkuhn) extending into the lamina propria from the bases
of the villi. Note the Paneth cells with eosinophilic granules located at
the bases of the crypts. (3) muscularis mucosae, located at the bases of the
intestinal glands and marking the boundary with the underlying submucosa of
loose connective tissue.
