CAPS 390 Lecture Notes - Lecture 29: Stratified Squamous Epithelium, Muscular Layer, Muscularis Mucosae
18 Nov 2015
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Reading: chapter 17 pp 381- 411. 29lect, gi- ii, nov 10, 2014 (dr. roskelley) Muscular tube that does not participate digestion or absorption. A conduit for transporting food from the pharynx to the stomach. Mucosa: stratified squamous, usually non- keratinized, protective. Lamina propria = loose connective tissue. Submucosa: dense irregular c. t that contains seromucous glands (anti- bacterial serous secretions, and lubricating mucous secretions) Initiates digestion (breakdown of food products) The folds flatten when the stomach is full: - stomach cells: surface lining cell, regenerative cell, mucous neck cell , Oxyntic parietal cell, zymogenic chief cell, enteroendocrine. Dnes/apud cell - see figure 17. 3. Zymogenic chief cells: secrete zymogens apically into lumen. Clinical correlation = barrett"s esophagus: Gastro- duodenal junction (stomach to small intestine): Gastro- esophageal junction (esophagus to stomach): abrupt transition from stratified squamous to columnar epithelium. Separated by lower esophageal/cardiac sphincter. Site of prominent thickening of sm. muscle in the muscularis externa = pyloric sphincter.
