Process of swallowing

Question 1

Swallowing involves two stages:

Answer 1

Oropharyngeal

Oesophageal

Question 2

Oropharyngeal comes first

Answer 2

1. Movement of bolus from mouth to oesophagus via pharynx
2. Tongue guides bolus to correct passageway
3. Process is highly coordinated

Question 3

Why is oropharyngeal a highly co-ordinated process?

Answer 3

1. When swallowing, airways are briefly sealed off -swallowing center temporarily inhibits the respiratory center
2. Uvula becomes elevated sealing back of throat and preventing food from entering nasal passage
3. Position of tongue against hard palate prevents food from re-entering the mouth
4. Position of tongue against hard palate prevents food from re-entering the mouth
   >Prevents food from entering the trachea
5. Epiglottis folds backwards over glottis
   >Added protection to prevent food from entering the respiratory airway
6. With the glottis closed, pharangeal muscles contract to force bolus into oesophagus

Question 4

‘fairly’ straight muscular tube extending from pharynx to stomach

Answer 4

Oesophagus

Question 5

Upper sphincter

Answer 5

Upper sphincter

Question 6

Lower sphincter

Answer 6

gastroesophageal

Question 7

why does a pressure gradient exist in the oesophagus?

Answer 7

Oesophagus exposed to subatmospheric intrapleural pressure (respiratory system)

Question 8

______ sphincter remains ______ (except when swallowing) to prevent air entering _____ oesophagus and stomach during breathing

Answer 8

Upper
closed
in

Question 9

Upper sphincter _____ (when swallowing) allowing bolus to pass into _____ .
The upper sphincter closes and ___________ open for breathing.
___________ stage is complete

Answer 9

opens
oesophagus
respiratory airways
Oropharyngeal

Question 10

Oesophageal stage

Answer 10

1. Movement of bolus from oesophagus to stomach
2. Triggered by swallowing center to induce peristalsis
   
   • Refers to ringlike contractions of smooth
     muscle pushing the bolus forward
   • Wave like motion = peristaltic wave
   • Lower sphincter relaxes to allow bolus to
     enter the stomach