CAPS 390 Lecture Notes - Lecture 28: Stratified Squamous Epithelium, Lamina Propria, Gastrointestinal Tract
18 Nov 2015
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Lecture 28 gi_i, nov 7th, 2014 (dr. roskelley) Digestive system is a tube- based organ system with a number of accessory glands. The digestive system consists of: oral cavity (today"s lecture, alimentary canal= gi tract (lect 29, accessory glands (lect 30) Is continuous with skin and has the same histology. Pinkness/redness is due to highly vascularized lamina propria. No hair or sweat and/or sebaceous glands. Continuous with the cheeks (=wet mucosa)/ similar histology to the cheeks. Lamina propria: dense irregular c. t. Submucosa: contains mucous glands to keep lips moistened. Adventitia: skeletal muscle (the orbicularis oris muscle, which is responsible for the puckering/movement of lips) Epithelium: lightly keratinized stratified squamous epithelium. Adventitia = bone (upper maxilla and lower mandible jaws) Odontogenesis (tooth formation): (see fig 16. 5 and drawing done in class) Begins in ~6 weeks after gestation: induction: dental placode (oral ectroderm) forms above mesenchyme. Mesenchyme underneath condenses to form a layer of odontoblasts (secrete/deposit extracellular dentin).
