#32 Esophagus, H&E

Examine the wall of the esophagus starting with the stratified squamous nonkeratinized epithelium, which covers the lumen. Underlying the epithelium is a layer of loose connective tissue and the muscularis mucosae. Note the thick muscularis externa.

#117 Small intestine, H&E

Identify the components of the wall of the small intestine. Use the laboratory manual as a guide to identify Paneth cells at the base of the intestinal crypts. These cells have accumulations of large acidophilic granules in their apical cytoplasm, and strongly basophilic basal cytoplasm.

#39 Colon, H&E

Note that the mucosa contains crypts and lacks villi. Also note the abundance of goblet cells in the lining of the crypts but not on the luminal surface; these features are diagnostic.

#106 Appendix, H&E

Examine the components of the wall of the appendix and compare them with the small and large intestine. In the mucosa of the appendix there is extensive accumulation of lymphocytes.