1. 1. Mechanism of swallowing (deglutition) PREPARED BY: MUHAMMAD ARIFF B. MAHDZUB BACHELOR MEDICINE AND SURGERY (MBBS) UNIVERSITY COLLEGE SHAHPUTRA, KUANTAN
2. 2. Mechanism of swallowing (deglutition) The sequence events: a. Buccal stage (voluntary) b. Pharyngeal stage (involuntary) c. Oesophageal stage (peristalsis)
3. 3. Buccal stage (voluntary) The tongue retracts to force the bolus into the oropharynx by the contraction of mylohyoid muscle
4. 4. a) protective phase They soft palate rises to close off nasopharynx and prevent bolus from rising into the nasal cavity The larynx elevate and the glottis closes(by epiglottis) Pharyngeal Stage (involuntary)
5. 5. Oropharyngeal isthmus closed (Base of tongue touching the soft palate) Pharyngeal constrictor contract
6. 6. b) pharyngeal peristalsis as pharyngeal constrictor contract, the UES relaxes to allow the bolus to move from the oropharynx into the upper oesophagus
7. 7. Oesophageal Stage (8-20 seconds) Primary peristalsis begins and both the LES and stomach relax The bolus moves into stomach and LES closes. water bolus moves by gravity while semisolid by peristalsis Peristalsis rapid in upper third while slow in lower third, it starts as primary ( continuation of pharyngeal) or secondary by oesophagus if primary failed
8. 8. PBL cases Ms Senna, got bulging at her neck
9. 9. Patient information sheet 2
10. 10. Bulging move up as its follow the larynx elevation (Pharyngeal Stage) Enlrg. thyroid wraps around esophagus Compressed the pharynx and oesophagus lead to Dysphagia -Swelling moves up during swallowing-
11. 11. -There s bruit heard over neck swallowing- Bruit : vascular murmur Causes: compression of enlarge thyroid gland to blood supply