A pathologist receives a normal specimen resected from a patient’s gastrointestinal tract. Under the microscope, she sees that the mucosa contains columnar cells lacking villi. There are many straight and long tubular glands. This specimen most likely originates from which portion of the GI tract?
Esophagus
Large intestine
Pharynx
Small Intestine
Stomach
Correct answer
Large intestine
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correct answer: B
The large intestine (choice B) contains the cecum and the colon. Its mucosa is composed of columnar cells lacking villi, and contains openings which give way to tubular glands known as the crypts of Lieberkuhn.
The mucosa of the esophagus (choice A) is composed of thick, stratified, squamous, nonkeratinized epithelium.
The pharynx (choice C) contains stratified, squamous epithelium, as well as ciliated, pseudostratified, columnar epithelium.
Intestinal villi are the hallmark of the small intestine (choice D). They are composed of outgrowths of the mucous membrane into the lumen. Crypts of Lieberkuhn are also found in the small intestine.
The stomach (choice E) mucosa contain simple, columnar cells, but lacks the crypts of Lieberkuhn.