Thorax 5: Superior and Posterior Mediastinum

Question 1

What are the subdivisions of the mediastinum

Answer 1

superior and inferior

Question 2

What is the inferior mediastinum divided further into

Answer 2

anterior, middle, and posterior

Question 3

What nerves are found in the superior mediastinum

Answer 3

phrenic, vagus, branches from sympathetic chain

Question 4

What can the superior mediastinum be further divided into

Answer 4

retrosternal
intermediate
prevertebral

Question 5

What are the contents of the retrosternal mediastinum

Answer 5

great vessels and thymus

Question 6

What are the contents of the intermediate mediastinum

Answer 6

aortic arch
great branches
ligamentum arteriosum
nerves (phrenic, vagus, sympathetic cardiac branches)

Question 7

Where is the brachiocephalic artery found and what will it divide into

Answer 7

comes off aorta on the right side: gives rise to subclavian and right common carotid

Question 8

Where does the vagus nerve course within the mediastinum

Answer 8

follow esophagus into the abdomen

branches to form left recurrent under arch of aorta (right recurrent under subclavian)

Question 9

What is contained in the prevertebral aspect of the superior mediastinum

Answer 9

trachea
esophagus
left recurrent laryngeal
lymph nodes
thoracic duct

Question 10

What structures are contained in the posterior mediastinum

Answer 10

thoracic aorta
esophagus (autonomic nerves)
thoracic duct
primary bronchi and nodes
azygos system

Question 11

What structures compose Kuleza’s triangle

Answer 11

thoracic aorta, azygos vein, and esophagus

Question 12

What is contained in Kuleza’s triangle

Answer 12

thoracic duct

Question 13

What type of arches are seen in the mediastinum

Answer 13

venous arch on right (azygos system)

arterial arch on left: aorta

Question 14

What structures are seen in the mediastinum form the right side

Answer 14

azygos vein, vagus

Question 15

What structures are seen in the mediastinum from the left side

Answer 15

aorta
vagus/left recurrent
esophagus

Question 16

What are the 3 places esophagus may become compressed

Answer 16

esophageal hiatus at diaphragm
where it crosses aorta
left main bronchus

Question 17

What are the 3 regions of muscle in esophagus

Answer 17

proximal 1/3: skeletal
middle 1/3: skeletal+ smooth
distal 1/3: smooth

Question 18

What is the arterial supply to neck esophagus

Answer 18

inferior thyroid

Question 19

What is the arterial supply to thoracic esophagus

Answer 19

branches from aorta

Question 20

What is the arterial supply to abdominal esophagus

Answer 20

celiac artery from left gastric artery

Question 21

What is the venous drainage of the esophagus

Answer 21

azygos: upper portion

portal system: lower portion

Question 22

Where might an adenocarcinoma (Barrett’s esophagus) within the abdominal esophagus spread

Answer 22

liver through the portal system venous system

Question 23

What is the innervation of the esophagus

Answer 23

parasympathetic: vagus
Symp: T1-T4

Question 24

What is Virchow’s node

Answer 24

sign of esophageal or gastric cancer

Question 25

Describe the relationship of the thoracic aorta to the esophagus

Answer 25

at first is positioned to the left then twists behind the esophagus

Question 26

What are the smaller branches off the thoracic aorta

Answer 26

``` bronchial pericardial posterior intercostal superior phrenic esophageal mediastinal ```

Question 27

What is coarctation of the aorta

Answer 27

narrowing of the aorta within the aortic arch, not completely occluded but impedes flow

Question 28

How will the body compensate for coarctation of the aorta

Answer 28

use collateral vessels: internal thoracic, anterior intercostals, posterior intercostals

Question 29

What does the azygos system drain

Answer 29

body wall

Question 30

Where does the azygos system return venous to

Answer 30

SVC

Question 31

What is the valsalva maneuver

Answer 31

exhaling forcibly with the glottis closed: compresses abdominal contents and backs blood up into azygos system

Question 32

What are the pros of the azygos system

Answer 32

ensures blood gets back to the heart

Question 33

What are the cons of the azygos system

Answer 33

valveless, easily spreads cancer, leads to skull and brain metastasis

Question 34

What is the cisterns chyli

Answer 34

large sac that collects lymph from lower body and intestines: termination of thoracic duct

Question 35

Where will the thoracic duct drain

Answer 35

left jugulovenous angle

Question 36

What will the sympathetic chain give off on the medial aspect

Answer 36

cardiac nerves: in neck | Splanchnic nerves: in thorax

Question 37

How many branches are found in greater, lesser, and least splanchnic nerves

Answer 37

greater: 3 lesser: 2 Least 1

Question 38

What patten do splanchnic nerves follow

Answer 38

GVAs preganglionic enter sympathethetic chain without synapsing and leave. synapse at ganglia near organ

Question 39

Where are preganglionic GVA cell bodies of splanchnic nerves found

Answer 39

bodies in IML