The Superior and Posterior Mediastinum - gross

Question 1

What are the divisions of the Mediastinum?

Answer 1

• Superior
• Inferior
• Anterior
• Middle
• Posterior

Question 2

What 6 structures are found in the Superior mediastinum?

Answer 2

• Thymus
• SVC & great vv.
• Arch of aorta & Great aa.
• Vagus nn. & Phrenic nn.
• Trachea & Esophagus
• Thoracic duct

Question 3

Why is the thymus?

Answer 3

Posterior to manubrium of sternum.

• Lies anterior to brachiocephalic vv.
• Functionally inactive & atrophies in adults.

Question 4

Where is the thymus?

Answer 4

Posterior to manubrium of sternum.

• Lies anterior to brachiocephalic vv.
• Functionally inactive & atrophies in adults.

Question 5

L. Branchiocephalic vein crosses _______ anteriorly.

Answer 5

Trachea

Question 6

L. Brachiocephalic vein crosses _______ anteriorly.

Answer 6

Trachea

Question 7

At what level does the Aortic arch begin and end?

Answer 7

T4-T5

Question 8

Aorta arches over ____ & _____.

Answer 8

Bronchus & pulmonary trunk

Question 9

_____ & _____ pass through the thoracic inlet between a vein and artery.

Answer 9

Vagus Nerves & Phrenic N.

Question 10

Vagus provides what kind of innervation to thorax and abdomen?

Answer 10

Parasympathetic

Question 11

Vagus Nerve provides what kind of innervation to thorax and abdomen?

Answer 11

Parasympathetic

Question 12

______ Descends to poster root of lung.

Answer 12

Vagus

Question 13

Phrenic Nerve provides what kind innervation to Diaphragm?

Answer 13

Somatic innervation

Question 14

______ Descends to anterior root of the lung.

Answer 14

Phrenic nerve

Question 15

_____ Descends immediately anterior to esophagus.

Answer 15

Trachea

Question 16

Where does the trachea bifurcate (level)?

Answer 16

at inferior limit of superior Mediastinum

Question 17

T or F, Numerous lymph nodes are found at the carina.

Answer 17

True

Question 18

What is the carina?

Answer 18

Septum-like structure where R & L main bronchi split.

Question 19

Which bronchi usually aspirate foreign objects?

Answer 19

The right main bronchus because its shorter, wider, and more vertically orient than left bronchus.

Question 20

What are the two types of Esophageal Hiatus?

Answer 20

Type I: sliding hiatal hernia

Type II: Paraesophageal hernia

Question 21

Describe type I esophageal hiatus…

Answer 21

• Stomach slides freely into thorax
• most common
• often asymptomatic

Question 22

Describe type II esophageal hiatus….

Answer 22

• fundus

- Often fixed in position risking gastric blood supply.

Question 23

Infection may spread from retropharyngeal space into _______.

Answer 23

Danger Space

Question 24

What is found in the Posterior Mediastinum?

Answer 24

• Esophagus & esophageal plexus
• Azygous system of vv.
  Descending Aorta
• Thoracic duct
• thoracic splanchnic nn.

Question 25

______ joins to form plexus around the esophagus (Esophageal plexus).

Answer 25

Vagus nn.

Question 26

L. Vagus N. = ?

Answer 26

Anterior Vagal trunk

Question 27

R. Vagus N. = ?

Answer 27

Posterior vagal trunk

Question 28

Both Vagal trunks pass through diaphragm with _____.

Answer 28

esophagus

Question 29

__________ drains intercostal vv from right side of thorax.

Answer 29

Azygous V.

Question 30

______ & _______ drains left thorax.

Answer 30

Hemiazygos & accessory hemiazygous vv.

Question 31

______ & _______ drains left thorax.

Answer 31

Hemiazygos & accessory hemiazygous vv. | *Both drain to azygous V.

Question 32

Where does Azygous V. drain?

Answer 32

Arches over right superior bronchus to drain into SVC

Question 33

______ lies just L of esophagus.

Answer 33

Descending Aorta

Question 34

Descending aorta gives rise to what?

Answer 34

- posterior intercostal aa. supplying thorax. | - supplies branches to trachea, bronchi & esophagus.

Question 35

Where is the thoracic duct?

Answer 35

Posterior to esophagus & anterior to vertebral bodies.

Question 36

Where is the thoracic duct?

Answer 36

Posterior to esophagus & anterior to vertebral bodies. *Between azygous v. & descending aorta.

Question 37

______ Enters the Venous angle between L subclavian V. & Left IJV.

Answer 37

thoracic duct

Question 38

What does the thoracic duct do?

Answer 38

drains lymph from entire body below diaphragm.

Question 39

________ is accumulation of lymph in pleural cavity.

Answer 39

chylothorax

Question 40

________ is accumulation of lymph in pleural cavity.

Answer 40

chylothorax

Question 41

What causes chylothorax?

Answer 41

Results from torn or leaking thoracic duct. | *Looks like massive white haze in chest cavity of x-ray film.

Question 42

What are the 2 thoracic branches from ganglia?

Answer 42

1st = postgang. symp. to thoracic viscera. 2nd = preganglionic symp. innervate the abdomen (not thorax) - grater splanchnic nn. - lesser splanchnic nn - least splanchinic nn.

Question 43

Thoracic Autonomic sympathetic nerves originate from what level?

Answer 43

T1-T5

Question 44

Thoracic autonomic parasymp. nerves originate from where?

Answer 44

CN X

Question 45

What 3 nerves commingle to form thoracic plexus of nerves?

Answer 45

- cardiac - Pulmonary - Esophageal