How does the structure of the esophagus differ from the rest of the GI tract?
The esophagus is unique in several ways. It is lined with stratified squamous epithelium, unlike the simple columnar epithelium found in the rest of the GI tract. Additionally, the muscularis externa in the upper third of the esophagus consists of skeletal muscle, transitioning to smooth muscle in the lower third. This arrangement facilitates voluntary control over swallowing at the beginning of the esophagus.
