Thorax: Posterior mediastinum and thoracic exit Flashcards
Major contents of the posterior mediastinum
Nerve plexus
Esophagus
Thoracic aorta and branches
Azygos system of veins
Thoracic duct
Sympathetic trunk and thoraco-splanchnic nerves.
At which vertebral levels does the oesophagus starts and ends?
Starts at C6 and ends at T11.
How does the oesophagus pass through the diaphragm?
Via the oesophageal hiatus at T10.
Four locations whereby the oesophagus is compressed?
- Junction btwn the pharynx and oesophagus.
- When it crosses the aorta.
- By the left main bronchus.
- At the oesophageal hiatus of diaphragm.
At which vertebral levels does the descending thoracic aorta starts and ends?
Starts at T4/T5 and ends at T12.
How does the thoracic aorta pass through the diaphragm?
Aortic hiatus of diaphragm.
Branches that are given off by the descending thoracic aorta? (7)
-Bronchial branches
-Mediastinal branches
-Oesophageal branches
-Pericardial branches
- Posterior intercostal arteries
-Subcostal artery
-Superior phrenic arteries
The azygos system of veins is made up of:
-Azygos vein (right)
-Accessory hemiazygos vein (left, superiorly)
-Hemiazygos vein (left, inferiorly)
How does the azygos vein enter the thorax?
Via the aortic hiatus of diaphragm or posterior to the right crus of diaphragm.
What are the tributaries of the azygos vein? (9)
-Right superior intercostal vein
-5th-11th posterior intercostal veins
-Hemiazygos vein
-Accessory hemiazygos vein
-Mediastinal vein
-Oesophageal vein
-Pericardial vein
-Right bronchial vein
-Right ascending lumbar and subcostal vein
How does the hemiazygos vein enter the thorax? (2)
It enters posterior to the left crus f the diaphragm, it may also enter via the aortic hiatus.
At which vertebral level does the hemiazygos vein cross the vertebral column to join the azygos vein?
T8
Tributaries of the hemiazygos vein? (4)
-9th-11th posterior intercostal veins
-Oesophageal vein
-Mediastinal vein
-Left bronchial vein (sometimes)
Tributaries of the accessory hemiazygos vein(2)
-4th/5th-8th posterior intercostal veins
-Left bronchial vein (sometimes)
Principal lymphatic channel that drains lymph from most of the body?
Lymphatic duct
At which vertebral level does the cysterna chyli extends?
L2
How does the thoracic duct enter the thorax?
Via the aortic hiatus
Which lymphatic vessels drain into the thoracic duct?
-The left jugular trunk and left subclavian trunk.
Where does the thoracic duct empty its contents?
At the junction btwn the left internal jugular and subclavian veins.
Lymphatic nodes responsible for the drainage of subcutaneous tissue?
Axillary lymph nodes
Five types of axillary lymph nodes
-Apical
-Central
-Anterior
-Posterior
-Lateral
Where do the axillary lymph nodes drain into?
The anterior, lateral, and posterior drain into the central.
-The central drains into the apical.
-Apical into the subclavian trunk.
Lymph nodes resp. for drainage of deeper tissues and thoracic wall? (3)
-Intercostal nodes
-Parasternal nodes
-Diaphragmatic nodes
Lymph nodes resp. for the drainage of sup. and deep lymphatic of lung?
Tracheobronchial nodes