Oesophagus

Question 1

Oesophagus - Location, Structure, Function

Answer 1

Location: Extends between pharynx and stomach, approximately 25cm long.
Structure: Muscular tube comprised of both skeletal and smooth muscle fibres. Divided into 3 portions. Collapsed when not in use.
Function: Involved in deglutition, propelling food bolus to the stomach.

Question 2

Oesophagus - Constriction Points

Answer 2

4 points

• Upper oesophageal sphincter (caused by cricopharyngeus muscle)
• Where it is crossed by arch of aorta
• Where it is crossed by left main bronchus
• Lower oesophageal sphincter/cardiac sphincter/gastroesophageal sphincter (Where it passes through the diaphragm at T10. Only a functional sphincter as it is a very slight thickening of circular muscle, reinforced by by diaphragm)

Question 3

Oesophagus - Histology

Answer 3

Mucosa - stratified squamous epithelium. Gastroesophageal junction is simple columnar epithelium.
Submucosa - mucous-secreting glands
Muscularis - superior 1/3 skeletal muscle, middle 1/3 mixture of skeletal and smooth, inferior 1/3 smooth muscle.
Outer layer - cervical and thoracic part have adventitia, abdominal part has serosa.