Oesophageal phase

Question 1

What happens in the oesophageal phase?

Answer 1

Involuntary sequence of reflex oesophageal muscle movements initiated by entry of food into the oesophagus

• peristaltic contractions of muscles in the oesophageal wall move the food down the oesophagus
• lower oesophageal sphincter relaxes and food enters stomach

Question 2

What triggers the oesophageal contraction?

Answer 2

Entry of food into upper oesophagus

Question 3

The oesophageal wall consists of an _________ muscle layer and an ____________ muscle layer

Answer 3

The oesophageal wall consists of an INNER CIRCULAR muscle layer and an OUTER LONGITUDINAL muscle layer (note opposite to arrangement of muscle layers in the pharynx)

Question 4

Peristalsis
Contraction of the _____ muscle layer behind the ______ propels it forward. ______ of both muscle layers at the ___________ eases bolus transit. Contraction of _______ in front of the ____ facilitates forward passage.

Answer 4

Contraction of the CIRCULAR muscle layer behind the BOLUS propels it forward. RELAXATION of both muscle layers at the LEVEL OF THE BOLUS eases bolus transit. Contraction of THE LONGITUDINAL LAYER in front of the BOLUS facilitates forward passage.

Question 5

When does the Lower Oesophageal Sphincter open?

Answer 5

It opens to allow food into the stomach
It relaxes during vomiting to allow forceful expulsion of stomach contents
Relaxation also occurs in gastro-oesophageal reflux. Acidity of stomach contents irritates the oesophageal mucosa (heartburn)