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The trachea extends from the lower border of the cricoid cartilage (C6) to the level of the sternal angle (T4/T5), where it divides into right and left bronchi.
It is about 10–12 cm long and 2 cm wide in adults.
It consists of 16–20 C-shaped hyaline cartilaginous rings, open posteriorly.
The trachealis muscle connects the open ends of the cartilage rings posteriorly.
Right bronchus is wider, shorter, and more vertical, hence foreign bodies commonly enter it.
The carina marks the bifurcation of the trachea; it is the most sensitive part for cough reflex.
The trachea is lined by pseudostratified ciliated columnar epithelium with goblet cells.
Blood supply – Inferior thyroid and bronchial arteries.
Nerve supply – Vagus (parasympathetic) and sympathetic trunks.
Tracheostomy is done between the 2nd and 4th tracheal rings.
The oesophagus is about 25 cm long and extends from the lower border of the cricoid cartilage (C6) to the cardiac orifice of the stomach (T11).
It passes through the diaphragm at the level of T10.
There are three natural constrictions at:
C6 – at the cricoid cartilage,
T4 – where it is crossed by the aortic arch,
T10 – where it pierces the diaphragm.
The upper third contains striated muscle, the middle third has mixed, and the lower third contains smooth muscle.
The lining epithelium is stratified squamous non-keratinized.
Venous drainage forms porto-systemic anastomosis between the azygos and left gastric veins.
Lymphatic drainage – Deep cervical, posterior mediastinal, and left gastric nodes.
Blood supply – Inferior thyroid, oesophageal branches of aorta, and left gastric arteries.
Nerve supply – Vagus (parasympathetic) and sympathetic trunks.
Clinical importance:
Achalasia cardia: failure of the lower oesophageal sphincter to relax.
Oesophageal varices: due to portal hypertension.
Tracheoesophageal fistula: abnormal communication between oesophagus and trachea.
Barium swallow study shows constrictions and pathological compressions.
The largest lymphatic vessel, about 45 cm long, beginning at the cisterna chyli (T12).
Enters the thorax through the aortic opening of the diaphragm.
Ascends in the posterior mediastinum, between the aorta (left) and azygos vein (right).
Crosses to the left side at T5, ascends in the superior mediastinum, and arches in the neck at C7 to open into the left venous angle (junction of left internal jugular and subclavian veins).
Drains lymph from the entire body below the diaphragm and the left half above it.
Major tributaries:
Left jugular trunk
Left subclavian trunk
Left bronchomediastinal trunk
Posterior intercostal and mediastinal lymph vessels
Clinical points:
Chylothorax: rupture of thoracic duct → chyle in pleural cavity.
Obstruction: due to tumors or fibrosis → lymphedema.
Injury during neck or thoracic surgery causes chyle leak.
Duplication of the thoracic duct may occur congenitally.
A young woman in her mid-pregnancy presented with rapid breathing and difficulty in swallowing.
She also gave a past history of sore throat accompanied by pain in her joints during childhood.
1. What is the likely diagnosis?
The most probable diagnosis is rheumatic heart disease, specifically mitral stenosis.
2. What is the cause of these symptoms?
Rheumatic fever, a post-streptococcal infection, damages the mitral valve, leading to mitral stenosis.
This results in obstruction to blood flow from the left atrium to the left ventricle, causing left atrial enlargement.
The enlarged left atrium lies anterior to the oesophagus and compresses it, producing dysphagia (difficulty in swallowing).
A barium swallow X-ray shows a characteristic indentation on the oesophagus due to the enlarged atrium.
The reduced cardiac output and pulmonary congestion from mitral stenosis lead to breathlessness and fatigue.
The rapid breathing (tachypnea) occurs because less oxygenated blood reaches the lungs and systemic circulation.
| Symptom | Anatomical Cause |
|---|---|
| Dysphagia | Compression of oesophagus by enlarged left atrium |
| Breathlessness | Pulmonary congestion due to mitral stenosis |
| Fatigue | Decreased oxygen delivery to tissues |
| Systolic murmur | Turbulent flow through stenosed mitral valve |
A barium swallow study demonstrates the indentation on the posterior wall of oesophagus, confirming left atrial enlargement secondary to mitral stenosis.
This case highlights the close anatomical relationship between the oesophagus and heart, showing how cardiac enlargement can produce gastro-oesophageal symptoms.
A young woman in her mid-pregnancy presented with rapid breathing and difficulty in swallowing, with a history of sore throat and joint pains in childhood.
Diagnosis:
Rheumatic heart disease (Mitral stenosis).
Anatomical Explanation:
Rheumatic fever damages the mitral valve, causing mitral stenosis and left atrial enlargement.
The oesophagus, lying immediately posterior to the left atrium, becomes compressed by the enlarged chamber, leading to dysphagia (difficulty swallowing).
A barium swallow test shows a posterior indentation of the oesophagus due to the enlarged atrium.
Impaired left ventricular filling and pulmonary venous congestion cause breathlessness and fatigue due to reduced oxygenation.
Thus, the clinical features are a direct consequence of the close anatomical relationship between the heart and the oesophagus
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.A newborn presents with frothing at the mouth, choking during feeding, and cyanosis.
Diagnosis:
Tracheoesophageal fistula (TEF) — abnormal communication between trachea and oesophagus.
Anatomical Explanation:
During embryonic development, incomplete separation of the trachea and oesophagus leads to a persistent connection.
Air passes into the stomach, and milk regurgitates into the lungs, causing aspiration pneumonia.
Surgical correction is required immediately to prevent respiratory complications
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.A middle-aged patient complains of difficulty swallowing solids and liquids, regurgitation, and chest discomfort.
Diagnosis:
Achalasia cardia — failure of the lower oesophageal sphincter to relax.
Anatomical Explanation:
Caused by degeneration or absence of ganglion cells in the myenteric plexus (Auerbach’s plexus) of the oesophageal wall.
The lower end of the oesophagus remains closed, and food accumulates, causing dilatation of the upper segment.
Barium swallow shows a bird’s beak appearance due to tapering of the distal oesophagus
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.A patient with liver cirrhosis presents with vomiting of blood (haematemesis).
Diagnosis:
Oesophageal varices due to portal hypertension.
Anatomical Explanation:
The lower end of the oesophagus contains a porto-systemic anastomosis between the left gastric vein (portal) and azygos vein (systemic).
In portal hypertension, these veins dilate to form varices that can rupture, causing massive upper GI bleeding.
Seen radiologically as worm-like shadows on barium swallow
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.A patient after neck dissection or thoracic surgery develops milky fluid collection in the pleural cavity.
Diagnosis:
Chylothorax — leakage of lymph due to thoracic duct injury.
Anatomical Explanation:
The thoracic duct, ascending behind the oesophagus and arching in the neck to open at the left venous angle, may be injured during surgery or trauma.
Lymph (chyle) containing fat droplets accumulates in the pleural space.
It causes respiratory distress and must be treated by ligation of the duct or drainage
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