Esophagus & Stomach 04

This oblique section of the esophagus was taken from slide H-41 in the student loan set. The mucosal epithelium (A) is stratified squamous; it is non-keratinized in humans but this is from a rhesus monkey and the epithelium may be keratinized. The muscularis mucosae is present as small bundles, such as at C, that may be hard to visualize. The large mucous glands (B) are in the submucosa. The fibers of the muscularis externa seen at D appear to be skeletal muscle fibers, which is characteristic of the proximal (upper) 1/3 of the esophagus. The letter E is placed over a small cluster of what appear to be lymphocytes; the entire gastrointestinal tract is part of the body's defense system and it frequently has lymphoid nodules as well as aggregates of diffuse lymphoid tissue.

Slide O-4, field S31/S32 of finder slide B, 2.5X objective