HTHSCI 1H06 Lecture Notes - Lecture 16: Splanchnic Nerves, Sympathetic Nervous System, Muscular Layer

• School: McMaster University
• Department: Health Sciences
• Course: HTHSCI 1H06
• Professor: Peter Helli

Document Summary

Food is passed from oral cavity to pharynx to esophagus. Epithelium - innermost part of the mucosa. For the proximal and distal part of the alimentary canal is stratified squamous epithelium, non keratinized. Rest is simple cuboidal or columnar epithelial. Lamina propria: connective tissue that glues the epithelium down to the muscle. Muscularis mucosa: thin layer of muscle; during contraction it can make the epithelium contort to weird folds. Submucosa: blood vessels, lymphatics, nerves and submucosal glands which dump their substances to the lumen of the gut are located here. Outer longitudinal: most of the alimentary canal. Serosa/adventitia: secretes a little fluid to allow visceral organs to move freely in the abdominal/pelvic cavity. Different for esophagus as it travelled down the mediastinum so it was glued in place (adventitia) Peristalsis: alternating waves of muscle contraction and relaxation used to move food through the gi tract. Also coordinates secretion of the alimentary canal and accessory organs.