Flashcards in Posterior mediastinum - descending (thoracic) aorta and oesophagus (dave's notes) Deck (18):
Where does the thoracic aorta commence?
T4, just to the left of the midline. Slanting until it sits in the midline.
Where does the oesophagus commence and terminate? How long is it?
25cm, commences at cricopharyngeus (cricoid cartilage) at C6 in the midline, running to the cardiac orifice at T10, 1" to the left of the midline.
What does the descending thoracic aorta give off?
9 posterior intercostal arteries, the subcostal artery, bronchial arteries and small oesophageal vessels.
What are the posterior relations of the oesophagus?
Initially in contact with the vertebral bodies, the oesophagus inclines forward so that it is in front of the thoracic aorta
How long is the intraabdominal part of the oesophagus?
What vessels are on the left and right of the oesophagus?
Crossed by the arch of the aorta on its left side, azygous on its right
What are the relations of the oesophagus relative to the pulmonary roots?
Below the tracheal bifurcation, the oesophagus is crossed by the left main bronchus and the right pulmonary artery
What is the general course of the oesophagus from the thoracic inlet?
From the thoracic inlet it inclines from the right to the left, posteriorly.
What is notable about oesophageal attachments just above the diaphragm?
Firm connective tissue with the aorta here.
What is the narrowest part of the oesophagus?
The cricopharyngeal sphincter (15cm from incisor teeth)
List the constrictions of the oesophagus
The cricopharungeal sphincter
-where it is crossed by the aortic arch (22cm from incisor teeth)
-crossed by the left main bronchus (27cm from incisor teeth)
-on passing into the diaphragm (38cm from incisor teeth)
If the left atrium is enlarged it can cause an indentation.
What is the blood supply and drainage of the upper 1/3rd of oesophagus?
Upper 1/3rd from the inferior thyroid artery, venous drainage to the inferior thyroid veins
What is the blood supply and drainage of the middle third of the oesophagus?
Middle third form the oesophageal branches of the aorta, venous to the azygous
What is the blood supply and drainage of the lower third of the oesophagus?
The left gastric artery, venous drainage to the left gastric vein.
Describe the lymphatic drainage of the oesophagus
Follows the arteries:
Upper third to deep cervical
Middle third to tracheobronchial group
Lower third to preaortic nodes.
Describe the structure of the oesophagus
Inner circular and outer longitudinal layers muscle; skeletal (for rapid contraction) to the upper third, visceral in the lower third.
What is the inner circular layer of oesophageal muscle in continuity with?
The cricopharyngeus muscle