1. Mechanism of swallowing (deglutition) PREPARED BY: MUHAMMAD
ARIFF B. MAHDZUB BACHELOR MEDICINE AND SURGERY (MBBS) UNIVERSITY
COLLEGE SHAHPUTRA, KUANTAN
2. Mechanism of swallowing (deglutition) The sequence events:
a. Buccal stage (voluntary) b. Pharyngeal stage (involuntary) c.
Oesophageal stage (peristalsis)
3. Buccal stage (voluntary) The tongue retracts to force the
bolus into the oropharynx by the contraction of mylohyoid
muscle
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. Oropharyngeal isthmus closed (Base of tongue touching the
soft palate) Pharyngeal constrictor contract
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. 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. PBL cases Ms Senna, got bulging at her neck
9. Patient information sheet 2
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. -There s bruit heard over neck swallowing- Bruit : vascular
murmur Causes: compression of enlarge thyroid gland to blood
supply