The Oesophagus
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Peritoneum and peritoneal
cavity | Main Anatomy Index | The Stomach
Last updated 30 March 2006
The Oesophagus
- The oesophagus (gullet) is a fairly straight muscular tube
(23 to 25 cm long) that extends from the pharynx to the stomach.
- It follows the curve of the vertebral column as it descends through the neck and posterior mediastinum.
- The oesophagus begins in the midline at the level of
the lower cricoid border (C6).
- It then deviates to the left at the root of the neck
and returns to the midline at T5.
- When it reaches T7, it once again deviates to the left
to reach the gastric cardia.
- It passes through the oesophageal hiatus of the
diaphragm at T10.
- The short abdominal part of the oesophagus (about 1 cm) forms a
groove in the left lobe in the liver.
- It ends at the level of T11 in the gastric cardiac
orifice.
- The muscle of the oesophageal wall is striated muscle
in the upper 1/3.
- It is mixed striated and smooth muscle in the middle 1/3.
- It is smooth muscle in the lower 1/3.
- At the inferior end of the oesophagus, the oesophagogastric
junction, there is a physiological mechanism known as the oesophageal
sphincter, which contracts and relaxes.
- This sphincter is normally quite efficient in preventing gastric reflux.
Constrictions of the
Oesophagus
- The oesophagus is the narrowest part of the gastrointestinal tract and has 4 major constrictions.
- At its beginning (C6), formed by the inferior constrictor of the
pharynx.
- At the point where it is crossed by the aortic arch at
level T4.
- At the left main bronchus
at level T5-T6.
- Where it crosses the diaphragm at the oesophageal hiatus
(T10).
- These constrictions are important as they are the likely sites of obstruction in the
event of oesophageal scarring due to the swallowing of caustic or acidic material.
Important Relations of
the Oesophagus
- The oesophagus is divided into 3 parts: cervical, thoracic and abdominal.
| Division |
Anterior |
Posterior |
Left |
Right |
| Cervical |
Trachea
Thyroid isthmus
Left recurrent laryngeal nerve |
Vertebrae
Longus colli muscle |
Left inferior thyroid artery
Left common carotid artery
Thyroid gland
Left subclavian artery
Thoracic duct |
Right common carotid artery
Right recurrent laryngeal nerve
Thyroid gland |
| Thoracic |
Trachea
Left main bronchus
Left vagus nerve
Diaphragm
Right pulmonary artery
Left common carotid artery |
Vertebrae
Right vagus nerve
Thoracic duct
Right posterior intercostal arteries |
Left pleura
Aortic arch
Thoracic aorta
Spleen
Fundus |
Right pleura
Azygos vein
Aorta
Coeliac plexus |
| Abdominal |
Anterior vagal trunk
Left liver lobe
Lesser omentum |
Vertebrae
Posterior vagal trunk
Left crus |
|
|
Blood Supply to the
Oesophagus
- Cervical part: inferior thyroid
branch of the thyrocervical trunk.
- Thoracic part: branches of the descending
aorta, bronchial arteries.
- Their direction of supply if generally longitudinal.
Venous Drainage of
the Oesophagus
- Cervical part: inferior thyroid
veins.
- The left gastric vein is a tributary of the portal vein,
so this is a site of portal-systemic anastomosis.
- In portal obstruction (e.g., cirrhosis of the liver)
the anastomotic veins may become varicose and burst into the lower
oesophagus, causing a fatal haemorrhage.
Nerve Supply of the
Oesophagus
- Cervical part: rami from the recurrent
laryngeal nerves and from the cervical sympathetic trunks
(via the plexus around the inferior thyroid artery).
- Thoracic part: branches from the vagal
trunks and the oesophageal plexus, sympathetic trunks and greater splanchnic
nerves.
- Abdominal part: supplies by vagal
trunks (anterior and posterior gastric nerves), thoracic
sympathetic trunks, greater and sometimes lesser splanchnic
nerves and the plexuses around the left
gastric and inferior phrenic arteries.
Lymphatic
Drainage of Oesophagus
- To the deep cervical, posterior
mediastinal and left gastric nodes.
- The latter drain into the coeliac nodes and from there,
the thoracic duct.
