Anatomy of the Trachea and Oesophagus Flashcards
What is the trachea, and where is it located?
The trachea is a fibrocartilaginous tube that connects the larynx to the bronchi, allowing the passage of air to the lungs.
What is the length and diameter of the adult trachea?
The adult trachea is about 10–12 cm long and 2 cm in diameter.
At which vertebral level does the trachea begin and end?
The trachea begins at the level of C6 and ends at the level of T4-T5 (the carina).
What structure marks the bifurcation of the trachea?
The tracheal bifurcation is marked by the carina at the level of the sternal angle (T4-T5).
What is the histological structure of the tracheal wall?
The tracheal wall consists of mucosa, submucosa, cartilaginous rings, and adventitia.
How many cartilaginous rings are present in the trachea, and what is their function?
The trachea has 16–20 C-shaped hyaline cartilage rings that maintain airway patency.
What type of cartilage forms the tracheal rings?
The tracheal rings are made of hyaline cartilage.
What structure connects the posterior ends of the tracheal rings?
The posterior ends of the tracheal rings are connected by the trachealis muscle.
What is the function of the trachealis muscle?
The trachealis muscle controls the diameter of the trachea and facilitates coughing.
What is the arterial supply of the trachea?
The arterial supply of the trachea comes from the inferior thyroid and bronchial arteries.
What is the venous drainage of the trachea?
The venous drainage of the trachea is via the inferior thyroid and brachiocephalic veins.
What is the lymphatic drainage of the trachea?
The lymphatic drainage of the trachea is to the pretracheal, paratracheal, and deep cervical lymph nodes.
What is the nerve supply of the trachea?
The trachea is innervated by branches of the vagus nerve, recurrent laryngeal nerves, and sympathetic fibers.
What are the relations of the trachea in the neck?
In the neck, the trachea is related to the thyroid gland, esophagus, and carotid sheath.
What are the relations of the trachea in the thorax?
In the thorax, the trachea is related to the aortic arch, esophagus, and left recurrent laryngeal nerve.
What is the clinical significance of the trachea in emergency airway management?
The trachea is a crucial site for intubation and emergency cricothyroidotomy.
What are common clinical conditions affecting the trachea?
Common tracheal conditions include tracheitis, stenosis, and tumors.
What is tracheomalacia, and what causes it?
Tracheomalacia is the weakening of tracheal cartilage, leading to airway collapse, often due to congenital defects.
What is the tracheoesophageal fistula, and how does it develop?
A tracheoesophageal fistula is an abnormal connection between the trachea and esophagus, usually congenital.
What is the function of the esophagus?
The esophagus transports food and liquids from the pharynx to the stomach.
Where does the esophagus begin and end?
The esophagus begins at C6 and ends at T11.
What is the length of the esophagus in adults?
The esophagus is approximately 25 cm long in adults.
What are the three parts of the esophagus?
The esophagus has cervical, thoracic, and abdominal parts.
What are the four anatomical constrictions of the esophagus?
The four esophageal constrictions are at the cricoid cartilage, aortic arch, left main bronchus, and diaphragm.
What is the histological structure of the esophageal wall?
The esophageal wall has four layers: mucosa, submucosa, muscularis, and adventitia.
How does the muscle composition of the esophagus change along its length?
The upper third contains skeletal muscle, the middle third is mixed, and the lower third is smooth muscle.
What is the arterial supply of the cervical esophagus?
The cervical esophagus is supplied by the inferior thyroid artery.
What is the arterial supply of the thoracic esophagus?
The thoracic esophagus is supplied by branches of the thoracic aorta.
What is the arterial supply of the abdominal esophagus?
The abdominal esophagus is supplied by the left gastric and inferior phrenic arteries.
What is the venous drainage of the esophagus?
The esophagus drains into the azygos, hemiazygos, and left gastric veins.
How does the venous drainage of the esophagus contribute to portal hypertension?
Esophageal venous drainage forms portosystemic anastomoses, which can lead to varices in portal hypertension.
What is the lymphatic drainage of the esophagus?
The esophagus drains into deep cervical, mediastinal, and left gastric lymph nodes.
What is the nerve supply of the esophagus?
The esophagus is innervated by the vagus nerve and sympathetic trunk.
What is the upper esophageal sphincter, and what is its function?
The upper esophageal sphincter prevents air from entering the esophagus during breathing.
What is the lower esophageal sphincter, and what is its function?
The lower esophageal sphincter prevents gastric reflux into the esophagus.
What is the Z-line in the esophagus?
The Z-line is the histological transition between the esophageal and gastric epithelium.
What are the major relations of the esophagus in the neck?
In the neck, the esophagus is related to the trachea, thyroid, and recurrent laryngeal nerves.
What are the major relations of the esophagus in the thorax?
In the thorax, the esophagus is related to the aortic arch, left atrium, and thoracic duct.
What are the major relations of the esophagus in the abdomen?
In the abdomen, the esophagus is related to the stomach and left gastric artery.
What is the esophagogastric junction, and why is it clinically significant?
The esophagogastric junction is the site of transition between the esophagus and stomach, prone to reflux disease.
What are common clinical conditions affecting the esophagus?
Common esophageal conditions include GERD, Barrett’s esophagus, and esophageal cancer.
What is gastroesophageal reflux disease (GERD), and what causes it?
GERD is caused by dysfunction of the lower esophageal sphincter, leading to acid reflux.
What is Barrett’s esophagus, and why is it important?
Barrett’s esophagus is metaplasia of the esophageal lining due to chronic acid exposure, increasing cancer risk.
What is esophageal achalasia?
Achalasia is a motility disorder caused by failure of the lower esophageal sphincter to relax.
What is an esophageal diverticulum?
An esophageal diverticulum is an outpouching of the esophageal wall, commonly in the pharyngoesophageal region.
What is the blood supply of the tracheoesophageal region in fetal development?
The tracheoesophageal region is supplied by branches of the pharyngeal arch arteries in fetal development.
What is the importance of the azygos vein in esophageal venous drainage?
The azygos vein provides a collateral pathway for venous drainage in cases of obstruction.
What is the role of the recurrent laryngeal nerve in relation to the esophagus and trachea?
The recurrent laryngeal nerve runs close to the trachea and esophagus, making it vulnerable to injury.
What is the clinical significance of an esophageal perforation?
Esophageal perforation can cause life-threatening mediastinitis and sepsis.
What is a cricopharyngeal spasm, and how does it affect swallowing?
Cricopharyngeal spasm is an overactivity of the upper esophageal sphincter, leading to difficulty swallowing.
