Spots Mediastinum

Question 1

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).

Answer 1

Ligamentum arteriosum

Question 2

What name is given to ligamentum arteriosum in embyro?

Answer 2

Ductus arteriosum

Question 3

What is the function of the embryological structure from which ligamentum arteriosum arises?

Answer 3

Ductus arteriosum works to shunt blood off from the lungs in utero.

Question 4

What structure lies immediately behind the ductus arteriosus/ligamentum arteriosus?

Answer 4

Left recurrent laryngeal nerve

Question 5

Where does the left current laryngeal nerve pass under?

Answer 5

The aortic arch

Question 6

Within which division of the mediastinum is the aortic arch located?

Answer 6

Superior mediastinum

Question 7

What is the surface marking of the aortic arch?

Answer 7

Behind the manubrium

Question 8

Where does the aortic arch start and finish?

Answer 8

At the level of the sternal angle for both

Question 9

At which vertebral levels are the openings in the diaphragm muscle and what passes through these openings?

Answer 9

T8 - opening for inferior vena cava in central tendon
T10 - oesophageal hiatus for oesophagus, vagus trunks
T12 - aortic hiatus for aorta, thoracic duct

Question 10

Where does the brachiocephalic trunk divide?

Answer 10

Behind the right sternoclavicular joint

Question 11

Name the dilatation at the end of the right common carotid artery.

Answer 11

Carotid sinus

Question 12

Within which division of the mediastinum are the sympathetic trunks located?

Answer 12

Superior and posterior mediastinum

Question 13

Describe the surface markings of the left brachiocephalic vein.

Answer 13

Crosses midline from left to right, posterior to manubrium of sternum

Question 14

Why is the left brachiocephalic vein more vulnerable to injury in children?

Answer 14

In children it rises above upper border of manubrium and is therefore less protected from injury

Question 15

From which nerve does the left recurrent laryngeal nerve arise?

Answer 15

Left vagus nerve

Question 16

Where are the vagus nerves located in relation to the root of the lung?

Answer 16

Posteriorly to reach oesophagus

Question 17

Where is the phrenic nerve located in relation to the root of the lung?

Answer 17

Anteriorly as they descend within the pericardial sac to reach the diaphragm

Question 18

What is the distribution of the right phrenic nerve?

Answer 18

Motor to diaphragm
Sensory to central aspects of diaphragm, fibrous pericardium and parietal layer of serous pericardium

Question 19

Describe the course of the azygos vein.

Answer 19

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

Question 20

Describe the course of the hemiazygos vein.

Answer 20

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

Question 21

Which chamber of the heart lies immediately anterior to the oesophagus?

Answer 21

Left atrium

Question 22

What vessels are closely related to the right vagus nerve in the neck region?

Answer 22

Right internal carotid artery and right internal jugular vein

Question 23

What nerve fibers are found within the left vagus nerve?

Answer 23

Parasympathetic nerves and visceral afferent nerve fibers

Question 24

From which vessel do the posterior intercostal arteries arise?

Answer 24

Descending aorta except the posterior intercostal arteries for the first 2 spaces which are supplied indirectly by the subclavian artery

Question 25

Which structures are medial to the left phrenic nerve and the right phrenic nerve?

Answer 25

R - Superior vena cava
L - Aortic arch

Question 26

List the locations in the aorta where a sudden deceleration may cause injury.

Answer 26

Aortic valve
Attachment of ligamentum arteriosum
As it passes through the diaphragm
AKA FIXED POINTS OF AORTA

Question 27

Describe the surface markings of the superior vena cava.

Answer 27

Lateral to sternum, between lower border of 1st right costal cartilage and lower border of 3rd right costal cartilage

Question 28

Where do the left and right brachiocephalic veins unite?

Answer 28

Behind lower border of first right costal cartilage

Question 29

What vessels unite to form the right brachiocephalic vein and what is the surface marking of this union?

Answer 29

Junction of internal jugular vein and subclavian vein
Union is behind the medial end of the right clavicle.

Question 30

Which blood vessel does the right recurrent laryngeal nerve loop around?

Answer 30

Right subclavian artery

Question 31

What nerve fibers are carried in the thoracic sphlanchic nerves?

Answer 31

Preganglionic sympathetic fibres
Visceral afferent fibres from abdomen

Question 32

In the superior mediastinum, describe the position of the left vagus nerve relative to the arteries.

Answer 32

Descends between left common carotid and left subclavian arteries
Crosses left side of aortic arch

Question 33

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?

Answer 33

azygos vein

Question 34

List the branches of the descending aorta.

Answer 34

Posterior intercostal arteries (9 pairs)
Right and left bronchial arteries
Oesophageal branches

Question 35

Where is the thoracic duct located?

Answer 35

Posterior, superior mediastinum

Question 36

Where does the thoracic duct drain into the venous system?

Answer 36

Junction of left internal and left subclavian veins