Anatomy of the Oesophagus: Structure, Relations and Clinical Anatomy
The oesophagus is a collapsible muscular tube that transports swallowed material from the laryngopharynx to the stomach. It begins at the lower border of the cricoid cartilage near C6, descends through the neck and posterior mediastinum, passes through the diaphragm at T10 and joins the stomach near T11.
C6 → posterior mediastinum → oesophageal hiatus at T10 → stomach. Natural constrictions are common sites for foreign-body impaction, corrosive injury and perforation.
Learning objectives
- Describe cervical, thoracic and abdominal parts.
- Identify wall layers, constrictions and relations.
- Outline vascular, lymphatic and nerve supply.
- Relate anatomy to dysphagia, reflux and foreign bodies.
Parts and course
| Part | Course and relations |
|---|---|
| Cervical | Begins behind the cricoid, lies posterior to trachea and anterior to vertebral column; recurrent laryngeal nerves ascend in the tracheo-oesophageal grooves. |
| Thoracic | Descends through superior then posterior mediastinum; related to trachea, left main bronchus, aortic arch, descending aorta, pericardium and vertebral bodies. |
| Abdominal | Short segment after the T10 hiatus, then joins gastric cardia near T11. |
Physiological constrictions
- Pharyngoesophageal junction: cricopharyngeal region near C6, about 15 cm from incisors.
- Aortic/bronchial crossing: where the aortic arch and left main bronchus cross.
- Diaphragmatic hiatus: at T10 before the gastro-oesophageal junction.
Some texts describe the aortic and bronchial impressions separately. These narrow points matter during endoscopy and explain why sharp objects, tablets and food boluses may lodge.
Wall structure
Non-keratinised stratified squamous epithelium protects against abrasion; the distal transition to gastric columnar epithelium forms the Z-line.
Contains vessels, nerves and mucus-secreting oesophageal glands.
Inner circular and outer longitudinal layers. Upper third is skeletal muscle, middle is mixed and lower third is smooth muscle.
Most of the oesophagus has adventitia; the short abdominal part has serosal covering.
Sphincters
The upper oesophageal sphincter is mainly formed by cricopharyngeus and prevents air entry and pharyngoesophageal reflux. The lower oesophageal sphincter is a physiological high-pressure zone supported by diaphragmatic crura, the angle of His and intra-abdominal pressure. Failure of this anti-reflux barrier contributes to gastro-oesophageal reflux.
Blood supply, veins and lymphatics
| Region | Arterial supply | Venous/lymphatic significance |
|---|---|---|
| Cervical | Inferior thyroid artery | Inferior thyroid veins; deep cervical nodes. |
| Thoracic | Oesophageal branches of thoracic aorta and bronchial arteries | Azygos system; posterior mediastinal nodes. |
| Abdominal | Left gastric and inferior phrenic branches | Left gastric/portal and azygos/systemic communication; gastric and coeliac nodes. |
Veins of the distal oesophagus connect portal and systemic circulations. Portal hypertension may produce oesophageal varices with life-threatening haemorrhage.
Nerve supply
Parasympathetic fibres are carried mainly by the vagal trunks and coordinate peristalsis and glandular activity. Sympathetic fibres arise through thoracic sympathetic pathways and carry vasomotor and pain-related signals. The enteric myenteric plexus coordinates smooth-muscle contraction; degeneration is central to achalasia.
Clinical anatomy
- Dysphagia: difficulty initiating a swallow suggests oropharyngeal dysfunction; food sticking after swallowing suggests oesophageal disease.
- Foreign body: common at natural constrictions and may threaten the airway or perforate the wall.
- Perforation: leakage causes deep-neck or mediastinal sepsis and requires urgent care.
- Reflux: repeated acid exposure can cause oesophagitis, stricture and Barrett change.
- Achalasia: impaired lower-sphincter relaxation and absent normal peristalsis produce dysphagia and regurgitation.
- Carcinoma: longitudinal submucosal lymphatics allow spread beyond the apparent lesion.
Connect this structure with the physiology of swallowing and foreign-body management in ENT.
Key examination points
- The oesophagus begins at C6 and passes through the diaphragm at T10.
- Upper third is skeletal muscle; lower third is smooth muscle.
- It has natural constrictions where foreign bodies lodge.
- Most of its outer surface is adventitia, not serosa.
- Distal veins form a clinically important portosystemic connection.
References and further reading
- NCBI Bookshelf: Anatomy, Thorax, Esophagus.
- NCBI Bookshelf: Physiology, Esophagus.
- NCBI Bookshelf: Barium Swallow.
For education only. Apply current Uganda Clinical Guidelines, local protocols and specialist advice.
