Spots Mediastinum Flashcards
Name the structure which connects the left pulmonary artery to the isthmus of aorta (final part of aortic arch or first part of descending aorta).
Ligamentum arteriosum
What name is given to ligamentum arteriosum in embyro?
Ductus arteriosum
What is the function of the embryological structure from which ligamentum arteriosum arises?
Ductus arteriosum works to shunt blood off from the lungs in utero.
What structure lies immediately behind the ductus arteriosus/ligamentum arteriosus?
Left recurrent laryngeal nerve
Where does the left current laryngeal nerve pass under?
The aortic arch
Within which division of the mediastinum is the aortic arch located?
Superior mediastinum
What is the surface marking of the aortic arch?
Behind the manubrium
Where does the aortic arch start and finish?
At the level of the sternal angle for both
At which vertebral levels are the openings in the diaphragm muscle and what passes through these openings?
T8 - opening for inferior vena cava in central tendon
T10 - oesophageal hiatus for oesophagus, vagus trunks
T12 - aortic hiatus for aorta, thoracic duct
Where does the brachiocephalic trunk divide?
Behind the right sternoclavicular joint
Name the dilatation at the end of the right common carotid artery.
Carotid sinus
Within which division of the mediastinum are the sympathetic trunks located?
Superior and posterior mediastinum
Describe the surface markings of the left brachiocephalic vein.
Crosses midline from left to right, posterior to manubrium of sternum
Why is the left brachiocephalic vein more vulnerable to injury in children?
In children it rises above upper border of manubrium and is therefore less protected from injury
From which nerve does the left recurrent laryngeal nerve arise?
Left vagus nerve
Where are the vagus nerves located in relation to the root of the lung?
Posteriorly to reach oesophagus
Where is the phrenic nerve located in relation to the root of the lung?
Anteriorly as they descend within the pericardial sac to reach the diaphragm
What is the distribution of the right phrenic nerve?
Motor to diaphragm
Sensory to central aspects of diaphragm, fibrous pericardium and parietal layer of serous pericardium
Describe the course of the azygos vein.
Arises in abdomen
Passes through diaphragm through the right aortic hiatus/crus to the posterior mediastinum
Runs upward along right side of vertebral bodies
Receives intercostal veins
Arches over the root of the right lung draining into the superior vena cava
Describe the course of the hemiazygos vein.
Arises in abdomen
Passes through the left aortic hiatus/crus of the diaphragm into the posterior mediastinum
Runs upward along left posterior intercostal veins
Receives from left posterior intercostal veins
Crosses to right side posterior to thoracic aorta and empties into the azygos vein
Which chamber of the heart lies immediately anterior to the oesophagus?
Left atrium
What vessels are closely related to the right vagus nerve in the neck region?
Right internal carotid artery and right internal jugular vein
What nerve fibers are found within the left vagus nerve?
Parasympathetic nerves and visceral afferent nerve fibers
From which vessel do the posterior intercostal arteries arise?
Descending aorta except the posterior intercostal arteries for the first 2 spaces which are supplied indirectly by the subclavian artery
Which structures are medial to the left phrenic nerve and the right phrenic nerve?
R - Superior vena cava
L - Aortic arch
List the locations in the aorta where a sudden deceleration may cause injury.
Aortic valve
Attachment of ligamentum arteriosum
As it passes through the diaphragm
AKA FIXED POINTS OF AORTA
Describe the surface markings of the superior vena cava.
Lateral to sternum, between lower border of 1st right costal cartilage and lower border of 3rd right costal cartilage
Where do the left and right brachiocephalic veins unite?
Behind lower border of first right costal cartilage
What vessels unite to form the right brachiocephalic vein and what is the surface marking of this union?
Junction of internal jugular vein and subclavian vein
Union is behind the medial end of the right clavicle.
Which blood vessel does the right recurrent laryngeal nerve loop around?
Right subclavian artery
What nerve fibers are carried in the thoracic sphlanchic nerves?
Preganglionic sympathetic fibres
Visceral afferent fibres from abdomen
In the superior mediastinum, describe the position of the left vagus nerve relative to the arteries.
Descends between left common carotid and left subclavian arteries
Crosses left side of aortic arch
During thoracic surgery, the surgeon noticed a sudden haemorrhage from the vessel which drains the posterior intercostal veins on the right side. which vessel is injured?
azygos vein
List the branches of the descending aorta.
Posterior intercostal arteries (9 pairs)
Right and left bronchial arteries
Oesophageal branches
Where is the thoracic duct located?
Posterior, superior mediastinum
Where does the thoracic duct drain into the venous system?
Junction of left internal and left subclavian veins
