ANHB1102 Lecture Notes - Lecture 17: Inferior Mesenteric Artery, Superior Mesenteric Artery, Gastric Mucosa
4 Dec 2018
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Pharyngeal constrictor muscles - force food down during swallowing. (pharynx connects to oesophagus). Covered in adventitia above diaphragm, travels through diaphragm, covered in serosa below diaphragm. Upper oesophageal sphincter - not anatomical just functional sphincter. Submucosa = glands for mucous to create food bolus. Muscularis mucosa contracts and increases folds in the tube. Mucosa = strati ed squamous (non-keratinised) for protection from abrasion. Some skeletal muscle at upper third. middle third is both. Lower third is smooth. skeletal muscle is faster than smooth so moves the food quickly past the airway. Food forced up to hard and soft palates, then back towards top of pharynx. Epiglottis tips and larynx rises to close airway. Peristalsis - controlled by the myenteric plexus. circular muscle constriction above food and relaxation below it. Cardiac sphincter relaxes and opens to allow food into he stomach. Start and end of tract are strati ed squamous and rest is columnar.
