3.3 Posterior Mediastinum

Question 1

Identify the Esophagus

Answer 1

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Question 2

Identify the Esophageal plexus and what it innervates.

Answer 2

Innervation on anterior surface of esophagus

Question 3

Identify the R and L vagus nerves

Answer 3

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Question 4

Identify the Thoracic duct and its function. Where does it drain?

Answer 4

Largest lymphatic vessel in the body. Drains into junction of the left subclavian vein and left internal jugular vein

Question 5

Identify the Trachea

Answer 5

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Question 6

Identify the Carina and its vertebral level.

Answer 6

Location of the trachea’s bifurcation as the left and right main/primary bronchi. This occurs at the T4/5 vertebral level.

Question 7

Identify the L and R main and primary bronchi

Answer 7

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Question 8

Identify the Thoracic aorta

Answer 8

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Question 9

Identify the Posterior intercostal artery. What does it supply?

Answer 9

Intercostal spaces.

Question 10

Identify the Esophageal arteries

Answer 10

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Question 11

Identify the Azygos vein. What are its major tributaries and where does it terminate?

Answer 11

Major tributaries include hemiazygous vein, bronchial veins, pericardial veins, and posterior right intercostal veins. Terminates at SVC.

Question 12

Identify the Posterior intercostal veins. Where do they drain?

Answer 12

Azygous vein.

Question 13

Identify the Arch of azygos

Answer 13

Region where azygous vein arches around right main bronchus.

Question 14

Identify the Accessory hemiazygos vein. What are its tributaries? Where and at what level does it terminate?

Answer 14

It receives the posterior intercostal veins from the superior aspect of the posterior thoracic wall on the left
Crosses the midline to join azygous vein around T8.

Question 15

Identify the Hemiazygos vein. What are its tributaries? Where and at what level does it terminate?

Answer 15

It receives the posterior intercostal veins from the inferior aspect of the posterior thoracic wall on the left.
Crosses the midline to join the azygos vein around T9

Question 16

Identify the Sympathetic trunk

Answer 16

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Question 17

Identify the Sympathetic (paravertebral) ganglia

Answer 17

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Question 18

Identify the Gray and white rami communicants. From where do these branch?

Answer 18

???

• Sympathetic efferents (motor inntervation): IML of spinal cord–> anterior root–> anterior ramus00> white rams communicants–> sympathetic trunk.
• From sympathetic trunk, they can go up, down, or stay at that level via gray rami communions. OR, pass thru sympathetic trunk–> thru splanchnic nerves–> synapse in paravertebral ganglia.

Question 19

Identify the Splanchnic nerves. From what nerve do these branch?

Answer 19

Come out of spinal nerves and travel inferiorly.

Question 20

Identify the Greater splanchnic nerve.

Answer 20

???

T5-T9 and provide autonomic innervation to abdominal viscera

Question 21

Identify the Intercostal nerves. Describe their course of origin.

Answer 21

A segmentally distributed ventral (anterior) ramus of a spinal nerve.