Oesophagus

Front 1

Basic anatomy 1

Back 1

1. Anatomical landmark
- starts at the end of oral cavity, at C6 vertebral level
- pierces diaphragm at T10 level
- enters cardia of stomach at T11 level

2. Arterial supply
- upper part: inferior thyroid artery
- middle part: bronchial arteries and direct tributaries from aorta
- lower part: left gastric and left phrenic artery

3. Venous drainage:
- upper and lower part: azygos vein and hemiazygos vein (to SVC)
- middle part: left gastric vein (to portal vein)

4. Lymphatic drainage:
- upper part: deep cervical nodes
- middle part: mediastinal nodes
- lower part: celiac nodes

5. Nervous supply:
- parasympathetic: vagus nerve
- sympathetic: cervical and thoracic sympathetic trunk

Front 2

Basic anatomy 2

Back 2

1. 4 constrictions
- behind cricoid cartilage
- behind left main bronchus and aorta
- when piercing the diaphragm

2. 2 sphincters
- upper and lower oesophageal sphincters
- functional, but not anatomical

3. Gastro-esophageal junction
- abrupt transition from non-keratinised stratified squamous epithelial cells of oesophagus to simple columnar epithelial cells of the stomach
- appear as Z line
- clinical implication in Barrett oesophagus in GERD

4. Structural adaptations to its function
A. Mucosa
- epithelium: non keratinised stratified squamous cells
- lamina propria: cardiac glands
- muscularis mucosae
B. Submucosa: mucus secreting glands
C. Muscularis propria
- upper part: striated skeletal muscles
- lower part: smooth muscles
- middle part: a mixture of both
- Auerbach plexus and myenteric plexus
D. Contains adventitia but not serosa

Front 3

Swallowing

Back 3

1. Phrase:
- buccal phrase
- pharyngeal phrase
- oesophageal phrase
Role of epiglottis: to cover larynx when swallowing occurs

2. Relaxation of upper oesophageal sphincter upon swallowing
3. Peristalsis of oesophagus
4. Relaxation of LES during peristalsis
5. Preventing gastric reflux by sphincter actions and anatomical constriction "angle of His"