Esophagus, upper - (10x objective lens)

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This mosaic image composed of several images, showing the upper esophagus at higher magnification, reveals more details of its structure: (1) The mucosa can be seen to be composed of three components: a thick, nonkeratinizing stratified squamous epithelium, resting on a lamina propria of loose connective tissue, and bounded by the muscularis mucosae, a layer of smooth muscle, which is discontinuous in this section. (2) The underlying submucosa is a thick layer of loose connective tissue, containing blood vessels, nerves, ganglia (Meissner's plexi) and, in places, glands. (3) The bulk of the outer wall of the esophagus is composed of the muscularis externa, consisting of two layers of muscle separated by a thin layer of connective tissue. The muscle fibers of the innermost (circular) layer are oriented with their long axes perpendicular to the long axis of the tube, whereas those in the outer (longitudinal) layer are oriented parallel to the long axis of the tube. In the upper esophagus, both layers are composed of skeletal muscle fibers. (4) The outermost layer of the upper esophagus, the adventitia, is formed of loose connective tissue that is continuous with the surrounding connective tissue of the mediastinum.

Stain = H&E

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