BIOL 221 Lecture Notes - Lecture 8: Dense Irregular Connective Tissue, Stratified Squamous Epithelium, Esophagus
4 Mar 2020
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Document Summary
Function: carries food from laryngopharynx to stomach. Passes through mediastinum and penetrates diaphragm at esophageal hiatus. The esophagus carries food from the laryngopharynx to the stomach. It passes through the mediastinum and penetrates the diaphragm at the esophageal hiatus. The esophagus averages around 25 cm (10 in. ) long with an average diameter of around 2 cm (3/4 ). Muscularis skeletal muscle then smooth muscle. The epithelium of the mucosa is stratified squamous epithelium. The submucosa includes esophageal glands that secrete mucus to help lubricate the food on its way through the esophagus. The muscularis changes from skeletal muscle in the superior portions to smooth muscle in the inferior portions. The portion in the thoracic cavity has an outer adventitia of dense irregular connective tissue. Lower esophageal (les; cardiac or gastroesophageal) sphincter. The upper esophageal sphincter (ues) controls movement of material from pharynx into esophagus and prevents regurgitation into the throat.
