Oesophagus

Question 1

What is the oesophagus?

Answer 1

A muscular tube between the pharynx and the stomach.

Function: passage of food from mouth to stomach
Location: upper digestive tract, between C6 and T11

Question 2

What are the sections of the oesophagus?

Answer 2

Cervical (C6-7)
Thoracic (T1-10)
Abdominal (below oesophageal hiatus in diaphragm at T10)

Question 3

What are the 4 constriction points of the oesophagus?

Answer 3

1. Upper oesophageal sphincter
   - pharyngoesophageal junction (C6)
   - caused by cricopharyngeus mm
2. Arch of aorta
3. Left main bronchus
4. Lower oesophageal sphincter
   - at gastro-oesophageal junction (T11)

Question 4

Describe the lower oesophageal sphincter

Answer 4

• located at the junction between the abdominal oesophagus and the stomach (approximately T11)
• not a true sphincter able to completely seal shut
• a functional sphincter formed by a thickening of the circular mm layer and reinforced by the diaphragm

Question 5

What are the two ways in which food moves down the oesophagus?

Answer 5

1. Deglutition (swallowing)
   a. buccal / voluntary phase
   b. pharyngeal oesophageal phase (involuntary, requires epiglottis to block trachea and upper oesophageal sphincter to be relaxed)
2. Peristasis
   - adjacent segments of the oesophageal wall alternately contract and relax to move bolus of food toward stomach

Question 6

Is the oesophagus intraperitoneal or extraperitoneal?

Answer 6

Extra/retroperitoneal (abdominal component)

Question 7

What type of cells form the mucosal layer of the oesophagus?

Answer 7

Stratified squamous epithelium in oesophagus

transition to simple columnar epithelium at gastroesophageal junction and into stomach

Question 8

What type of muscle forms the muscularis layer of the oesophagus?

Answer 8

Superior third: skeletal muscle (voluntary control)
MIddle third: combination of skeletal and smooth mm
Lower third: smooth muscle (involuntary control)

Question 9

Which layers of the oesophageal wall are capable of secreting mucus?

Answer 9

Mucosal layer (lamina propria has mucosal oesophageal glands)

Submucosal layer (submucosal oesophageal glands)

Question 10

What is the arterial supply of the oesophagus?

Answer 10

From aorta:

• branches of thyroid arteries
• oesophageal arteries
• left inferior phrenic artery

From celiac trun:
- left gastric artery

Question 11

What is the venous drainage of the oesophagus?

Answer 11

Inferior thyroid veins 
Oesophageal veins (into azygous)
Left gastric vein (into portal)

Question 12

What are the 4 lymphatic nodes that the oesophagus drains into?

Answer 12

Paratracheal
Inferior deep cervical
Posterior mediastinal
Left gastric

Question 13

Which nerves innervate the oesophagus?

Answer 13

Upper half of cervical section:
- recurrent laryngeal (branch of CNX)

Rest of oesophagus:
PNS: CNX Vagus
SNS: cardiopulmonary splanchnic nn, and greater and lesser abdominopelvic splanchnic nn via cervical sympathetic ganglia