Oesophagus Flashcards
To learn anatomy
Length
Breadth
How is the lumen flattened
25 cm
2 cm
Flattened antero posteriorly
Course
The oesophagus begins in the neck at the lower border of the cricoid cartilage(the lower border of of C6 vertebra) ,descends in the front of the vertebral column ,passes through superior and posterior mediastina,pierces the diaphragm at the level of the T10 vertebra and ends in the abdomen at the cardiac orifice of the stomach at the level of the T11 vertebra
Curvatures of oesophagus
Two anteroposterior curvatures
- Corresponding to the curvature of cervical spine
- Corresponding to the curvature of thoracic spine
Two side to side urvatures to the left
- At the root of the neck, before entering the thoracic inlet
- T7 vertebra before passing in front of the descending thoracic aorta
Constrictions in oesophagus
- C6,6 in,cricipharyngeous
- T4, 9in,aortA
- T7,11in,left principal bronchus
- TWO,15 in, diaphragm
What is the narrowest part of oesophagus
Commencement at the cricopharyngeal sphincter
Clinical significance of the construction
- Foreign bodies
- Corrosive substances
- Predilection for carcinoma
- Difficulty of passing oesophagoscope
Parts of oesophagus
3 parts
1. Cervical 4cm
From the cricoid cartilage to the upper border of manubrium sterni
2. Thoracic 20 cm till the oesophageal opening of the diaphragm
- Abdominal till the cardiac end od the stomach.1-2cm
Anterior relations
Trachea Arch of aorta Right pulmonary artery Left principal bronchus Left atrium Diaphragm
Posterior relations
Vertebral column Right posterior intercostal arteries Thoracic duct Azygos vein Hemiazgos Descending thoracic aorta
Relations of the right side
Right lung and pleura
Azygos vein
Right vagus nerve
Left relations
Left lung and pleura Arch of aorta Left subclavian artery Thoracic duct Left recurrent laryngeal nerve Descending thoracic aorta
Anterior relations of the abdominal part of oesophagus
Pósterior surface of the left live of liver
Left gastric nerve
Posterior relations of the abdominal part of oesophagus
Left crus of diaphragm
Right gastric nerve
Specialty of abdominal part
Shortest
Covered by peritoneum
Arterial supply
Cervical- inferior thyroid artery
Thoracic- oesophageal branches of descending thoracic aorta and bronchial arteries
Abdominal - oesophageal branches of left gastric artery and left inferior phrenic artery
Venous drainage
Cervical part is drained by inferior thyroid veins . Thoracic part is drained by azygos vein and hemiazgos vein. Abdominal part is drained by two Venus channels namely hemizygous vein a tributary of inferior Vena cava and left gastric vein, a tributary of portal vein. Thus the abdominal part of the oesophagus is the site of portacaval anastomosis.
Oesophageal varices
The lower end of the oesophagus is one of the important sides of portocaval anastomosis . In portal hypertension, for example, due to cirrhosis of liver there is back pressure in portal circulation as a result collateral channels of portacaval anastomosis not only open but become dilated and tortuous to form oesophageal varices. The ruptured oesophageal varices cause hematemesis( vomiting of blood).
Lymphatic drainage
Cervical,- deep cervical lymph nodes
Thoracic- posterior mediastinal lymph nodes
Abdominal- left gastric and Coeliac lymph nodes
Nerve supply
P symp- recurrent laryngeal nerve and oesophageal plexus of vagus
Symp- T5*T9
Where is the pain referred to
Lower thoracica and epigastric
Microscopic structure
- Mucosa- epithelium,lamina propria,muscularis mucosa
- Submucosa
- Muscular- 3 different parts and muscles
- Adventita
Barret’s oesophagus
A clinical condition where the squamous epithelium of the oesophagus is replaced by the gastric epithelium. It canead to oesophageal carcinoma.
Development and abnormalities
It develops from the foregut.
Failure of canalisation leads to oesophagial atresia
(@) separation of laryngotracheal tube by the formation of laryngotracheal septum
(b) recanalization of the obliterated lumen
Radiological examination
it is performed to detect the enlargement of the left atrium due to mitral stenosis , oesophageal strictures, and carcinoma and achlasia cardia.
Oesophagoscopy
it is performed to visualise the interior of the oesophagus while passing is the oesophagoscope is sites of normal constructions should be kept in mind.
Most common motility disorder of the oesophagus
Achlasia cardia
it is a clinical condition in which the sphincter at the lower end of the oesophagus fails to relax when food is swallowed as a result food accumulates in the oesophagus and is regurgitation occurs . This condition occurs probably due to the congenital absence of ganglion cells in the myenteric plexus of nerves in the oesophageal wall a radiographic barium swallow examination of the oesophagus is a characteristic birds beak or rat tail appearance.
Causes of dysphagia
(a) compression of the oesophagus from outside by the aortic arch aneurysm,enlargement of lymph nodes,ab normal right subclavian artery passing posterior to the oesophagus and
(b) narrowing of a lumen due to stricture or carcinoma.
Most common congenital anomalies of oesophagus
Tracheo oesophageal fistula:-
It is the most common congenital anomaly of the oesophagus that occurs due to the failure of separation of the lumen of the tracheal tube from that of oesophagus by a laryngotracheal septum. In the most common type of tracheoesophageal fistula, the upper oesophagus ends blindly and the lower oesophagus communicates with the trachea at the level of T4 vertebra
Clinically it presents as hydraminos because the foetus is unable to swallow amniotic fluid, stomach is distended with air and infant vomiting every feed given on may cough up bile. The fistula must be closed surgically to avoid the passage of swallowed liquid into the lungs.
Commonest site of cancer in the oesophagus
It most commonly occurs in its lower one third . Drains into celiac lymph nodes.
