The esophagus is a strong muscular tube that moves food from the oropharynx to the stomach. The lumen of the esophagus is lined by a thick protective stratified squamous epithelium. Underlying the epithelium is the lamina propria (containing scattered lymphoid aggregations) and the muscularis mucosa. The highly vascular submucosa lies below the muscularis mucosa and contains small mucous glands that aid in lubrication. These glands are located in the distal third of the esophagus. The muscularis propria is a thick inner circular and outer longitudinal layer of smooth muscle. In the proximal third of the esophagus, skeletal muscle can be seen in the muscularis mucosa (as the first part of swallowing is under voluntary control).

At the junction of the esophagus and stomach, the mucosa undergoes a transition from the protective stratified squamous epithelium to a tightly packed glandular secretory mucosa that contains columnar cells. The muscularis mucosa, the underlying submucosa, and the muscularis propria remain continuous between the mucosal junction.

Given the vast number of cell types present in the esophagus, a variety of tumors can arise. Spindle cell carcinoma, small-cell carcinoma, leiomyosarcoma, Kaposi's sarcoma, and malignant melanoma comprise rare malignant esophageal tumors. The vast majority of primary malignant tumors of the esophagus, however, include squamous cell carcinoma and adenocarcinomas.

Health And Fitness 101

Health And Fitness 101

Self-improvement is a thing which you must practice throughout your life because once you started to believe that you are perfect then, things will start to become complex. You need to know that no one is perfect and no one can be perfect.

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