Esophagus
Updates to Article Attributes
The oesophagus (plural: oesophagi or oesophaguses) is a muscular tube that conveys food and fluids from the pharynx to the stomach. It forms part of the upper gastrointestinal tract.
Gross anatomy
The oesophagus is 23-37 cm long with a diameter of 1-2 cm and is divided into three parts:
cervical: continuous with the hypopharynx, commences at the lower border of cricoid cartilage (at level of C5/6) or cricopharyngeus muscle
thoracic: from superior thoracic aperture (T1) to the oesophageal hiatus (T10) in the diaphragm which covers the inferior thoracic aperture
abdominal: from oesophageal hiatus and is continuous with the cardia of the stomach at the gastro-oesophageal junction
The cervical oesophagus begins at the upper oesophageal sphincter, which is formed by the cricopharyngeus muscle 6.
The oesophagus then descends to the left of the midline through the neck and superior mediastinum, returning to the midline at T5, before coursing to the left of the midline once more, in the posterior mediastinum. The distal thoracic oesophagus then curves anteriorly to pass through the diaphragm into the abdominal cavity.
The lower oesophageal sphincter, a specialised region of the circular muscle of the distal oesophagus, manifests itself radiographically as the phrenic ampulla (a.k.a. oesophageal vestibule), a 2-4 cm long dilatation between the A-ring and B-ring 6.
There are three normal oesophageal constrictions that should not be confused for pathological constrictions:
cervical constriction: due to cricoid cartilage at the level of C5/6
thoracic constriction: due to aortic arch at the level of T4/5
abdominal constriction: at oesophageal hiatus at T10/11
Relations
posteriorly: vertebral column; descending aorta; thoracic duct (at thoracic plane); accessory hemiazygos and hemiazygos veins (at T8/9)
anteriorly: trachea (to T4/5); recurrent laryngeal nerves (in tracheo-oesophageal groove); left main bronchus; left atrium
left lateral: lung; pleura; aorta; left subclavian artery; thoracic duct
right lateral: lung; pleura; azygos vein
Arterial supply
upper third: inferior thyroid artery
middle third: oesophageal branches of the thoracic aorta
lower third: oesophageal branches of the left gastric artery
Venous drainage
upper third: inferior thyroid veins to brachiocephalic veins
middle third: azygos vein to SVC
lower third: left gastric vein to portal vein (site of portal-systemic collateral pathway)
Lymphatic drainage
Follows arterial supply:
upper third: deep cervical lymph nodes
middle third: posterior mediastinal lymph nodes
lower third: left gastric and coeliac group lymph nodes
Innervation
Histology
The oesophagus is made up of five layers, noting there is no serosal layer. From outer to inner, these are:
adventitia
-
muscularis propria
outer longitudinal muscularis propria
inner circular muscularis propria (in the upper one-third of the oesophagus this layer is composed of striated (voluntary) muscle while the lower two-thirds is smooth muscle)
submucosa
-
mucosa
stratified squamous epithelium that abruptly changes to columnar epithelium in the lower oesophagus
Variant anatomy
aberrant right subclavian artery passing anterior or posterior to the oesophagus
Radiographic appearance
Barium swallowFluoroscopy
modified barium swallow is used to evaluate pharyngeal motility during swallowing
,; the procedure utilises barium of varying consistencies given by mouth with video recording of swallowingbarium swallow is the main radiological method of assessing the oesophagus
. Double; double contrast oesophagogram using CO2 gas-forming crystals and barium contrast are used to distend the oesophagus and coat the mucosa.
Ultrasound
Endoscopic ultrasonography
Endoscopic ultrasonography is used for evaluation of the depth of the oesophageal tumour.
CT
80% will contain gas allowing for appreciation of the wall if there is enough surrounding mediastinal fat
if collapsed will appear as round or ovoid
MRI
T1:
:isointense to muscleT2:
:hyperintense to muscle
Nuclear medicine
PET-CT
Useful for the staging of oesophageal cancer.
Related pathology
-<li><p><a href="/articles/vagus-nerve" title="Vagal trunk">vagal trunk</a> (<a href="/articles/parasympathetic-nervous-system" title="Parasympathetic nervous system">parasympathetic</a> fibres)</p></li>- +<li><p><a href="/articles/vagus-nerve" title="Vagal trunk">vagal trunk</a> (<a href="/articles/parasympathetic-nervous-system" title="Parasympathetic nervous system">parasympathetic fibres</a>)</p></li>
-</ul><h4><strong>Variant anatomy</strong></h4><ul>- +</ul><h4>Variant anatomy</h4><ul>
-</ul><h4>Radiographic appearance</h4><h5>Barium swallow</h5><ul>-<li><p>modified barium swallow used to evaluate pharyngeal motility during swallowing, the procedure utilises <a href="/articles/barium-sulfate-contrast-medium">barium of varying consistencies</a> given by mouth with video recording of swallowing</p></li>-<li><p><a href="/articles/barium-swallow">barium swallow</a> is the main radiological method of assessing the oesophagus. Double contrast oesophagogram using CO<sub>2</sub> gas-forming crystals and barium contrast are used to distend the oesophagus and coat the mucosa.</p></li>-</ul><h5>Ultrasound</h5><h6>Endoscopic ultrasonography</h6><p><a href="/articles/endoscopic-ultrasound">Endoscopic ultrasonography</a> is used for evaluation of the depth of the oesophageal tumour.</p><p>CT</p><ul>-<li><p>80% will contain gas allowing for appreciation of wall if there is enough surrounding mediastinal fat</p></li>- +</ul><h4>Radiographic appearance</h4><h5>Fluoroscopy</h5><ul>
- +<li><p><a href="/articles/videofluoroscopic-swallow-study" title="Modified barium swallow">modified barium swallow</a> is used to evaluate pharyngeal motility during swallowing; the procedure utilises <a href="/articles/barium-sulfate-contrast-medium">barium of varying consistencies</a> given by mouth with video recording of swallowing</p></li>
- +<li><p><a href="/articles/barium-swallow">barium swallow</a> is the main radiological method of assessing the oesophagus; double contrast oesophagogram using CO<sub>2</sub> gas-forming crystals and barium contrast are used to distend the oesophagus and coat the mucosa</p></li>
- +</ul><h5>Ultrasound</h5><p><a href="/articles/endoscopic-ultrasound">Endoscopic ultrasonography</a> is used for evaluation of the depth of the oesophageal tumour.</p><h5>CT</h5><ul>
- +<li><p>80% will contain gas allowing for appreciation of the wall if there is enough surrounding mediastinal fat</p></li>
-<li><p><strong>T1</strong>: isointense to muscle</p></li>-<li><p><strong>T2</strong>: hyperintense to muscle</p></li>- +<li><p><strong>T1:</strong> isointense to muscle</p></li>
- +<li><p><strong>T2:</strong> hyperintense to muscle</p></li>