213.A 52-year-old woman with a provisional diagnosis of celiac disease
presents with bouts of diarrhea and extreme fatigue. Verification was
sought through performance of esophagogastroduodenoscopy to obtain
small bowel biopsies. Biopsies of the region shown in the accompanying
light micrograph disclose hyperplasia of the structures labeled with the
asterisks. The labeled structures produce which of the following?
Gastrointestinal Tract and Glands 321a. Acid
b. Mucus and HCO 3 −
c. Pepsinogen
d. Lysozyme
e. Enterokinase