Thorax 7 - Superior & Anterior Mediastinum

Question 1

Where are the vagus and phrenic nerves positioned in relation to each other?

Answer 1

Phrenic nerves lie lateral to the vagus nerves

Question 2

Which section of the aorta lies in the superior mediastinum?

Answer 2

Aortic arch

Question 3

In relation to where the common carotid artery arises from the aorta, where does the subclavian arise?

Answer 3

Posterior

Question 4

Which directions does the aortic arch travel?

Answer 4

Superiorly
Posteriorly
To the left

Question 5

What landmark marks the superior point of the thymus?

Answer 5

Jugular notch

Question 6

What landmark marks the inferior point of the thymus?

Answer 6

4th cc

Question 7

In which mediastinum is the thymus found?

Answer 7

Anterior

Question 8

Which structures does the thymus lie between?

Answer 8

Posterior to manubrium & body of sternum

Anterior to pericardium

Question 9

What is the function of the thymus?

Answer 9

To programme T-lymphocytes

Question 10

Where do the internal jugular and subclavian veins join and become the brachiocephalic vein?

Answer 10

Posterior to the sternoclavicular joint

Question 11

Which aspect of the arch of the aorta does the LBCV pass closest to?

Answer 11

Anterior

Question 12

Does the LBCV pass anterior to the manubrium?

Answer 12

No

Question 13

Where do the RBCV & LBCV meet to become the SVC

Answer 13

Posterior to 1st right cc

Question 14

Where does the azygos vein join the SVC?

Answer 14

Posterior to 2nd right cc

Question 15

At what level does the SVC enter the right atrium?

Answer 15

Posterior to 3rd right cc

Question 16

Is the pulmonary trunk in the superior mediastinum?

Answer 16

No

Question 17

Is the ligamentum arteriosum in the superior mediastinum?

Answer 17

Yes

Question 18

What are the boundaries of the anterior mediastinum?

Answer 18

Sternum, pericardium, lungs & pleura

Question 19

What are the boundaries of the superior mediastinum?

Answer 19

Thoracic inlet, sternal angle (T4/5), posterior to manubrium, anterior to T1-4, oblique from manubrium up to T1, lungs & pleura

Question 20

Where does the aortic arch lie?

Answer 20

At the level of T4/5

Question 21

At the level of T3, where do the vagus nerves lie in relation to the phrenic nerves?

Answer 21

Medially & Posteriorly

Question 22

At what spinal level does the bifurcation of the trachea into bronchi occur?

Answer 22

T5/6

Question 23

Between what two landmarks does the thymus lie?

Answer 23

Jugular notch

4th CC

Question 24

From which two arteries does the thymus get its blood supply?

Answer 24

Internal thoracic

Inferior thyroid

Question 25

Which vein carries blood away from the thymus?

Answer 25

Left brachiocephalic

Question 26

Where are the right and left BCV's formed and which veins form them?

Answer 26

Posterior to the sternoclavicular joints. | Internal jugulars and subclavians

Question 27

Venous drainage: 1. Azygos 2. Subclavian 3. Internal jugular 4. LBCV

Answer 27

1. posterior chest wall 2. UL 3. head & neck 4. anterior chest wall (via internal thoracic veins)

Question 28

Which vein do the azygos, subclavian, internal jugular and LBC veins drain to?

Answer 28

SVC

Question 29

Which veins may be at risk during tracheostomy in children?

Answer 29

Thyroid veins, since in children they may protrude above the manubrium

Question 30

A key note to remember...

Answer 30

The nerves lie BETWEEN the arteries and veins

Question 31

Which arteries are contained in the superior mediastinum?

Answer 31

``` Arch of aorta (NOT descending aorta) BCT Right subclavian Right common carotid Left subclavian Left common carotid ```

Question 32

With regard to landmarks, where does the arch of aorta lie?

Answer 32

Sternal angle - T4/5 plane

Question 33

At which spinal level does the PT bifurcate?

Answer 33

T5

Question 34

Where does the PT lie in relation to the aorta?

Answer 34

To the left

Question 35

In which mediastinum does the ligamentum arteriosum lie?

Answer 35

Superior

Question 36

What are the C shaped rings in the trachea made of?

Answer 36

Hyaline cartilage

Question 37

What is the carina?

Answer 37

Tracheal bifurcation

Question 38

Between which spinal levels does the trachea run?

Answer 38

C6 - T4/5

Question 39

What structure lies between the trachea (anterior) and the oesophagus (posterior)?

Answer 39

Left recurrent laryngeal nerve

Question 40

When does trachealis muscle contract and when does it relax?

Answer 40

Contracts at rest | Relaxes upon exertion (greater capacity)

Question 41

At which spinal level does the oesophagus start?

Answer 41

C6

Question 42

Between which two structures does the thoracic duct lie?

Answer 42

Azygous vein | Thoracic aorta

Question 43

In which mediastinum does the thoracic duct lie?

Answer 43

Extends from posterior mediastinum up to the superior mediastinum

Question 44

What assists lymph movement?

Answer 44

Aortic pulsations

Question 45

At which vertebral level does the thoracic duct cross behind the oesophagus to ascend on its left side?

Answer 45

T4/5

Question 46

Where does the thoracic duct enter the venous system?

Answer 46

At the junction between the left internal jugular and the left subclavian veins, i.e. the LBCV

Question 47

What pathology can affect the left recurrent laryngeal nerve and what would the result of this be?

Answer 47

Left lung tumours | Causes hoarse voice

Question 48

To which lymph nodes does the lung and lung hilum lymph drain to?

Answer 48

Mediastinal

Question 49

Where can mediastinal lymph nodes be found?

Answer 49

Clustered around the trachea and oesophagus in the superior mediastinum

Question 50

Where do superior tracheobronchial lymph nodes lie?

Answer 50

Above the carina (tracheal bifurcation)

Question 51

Where do inferior tracheobronchial lymph nodes lie?

Answer 51

Below the carina

Question 52

Where might palpable lymph nodes be found in lung tumour cases and why?

Answer 52

Neck - due to communication with deep cervical lymph nodes

Question 53

Around which structure can anterior lymph nodes be found?

Answer 53

Brachiocephalic veins