Superior & Posterior Mediastinum

Question 1

Define mediastinum

Answer 1

mass of tissues & organs separating the 2 lungs

Question 2

Where is the mediastinum located

Answer 2

Located between sternum in front & vertebral column behind
Located from thoracic inlet above to diaphragm below

Question 3

What does the mediastinum contain within it?

Answer 3

Contains all structures in thorax, except the lungs!

Question 4

What is within the 5 different boundaries of the mediastinum?

Answer 4

Anterior: sternum & costal cartilages
Posterior: thoracic vertebral bodies
Superior: thoracic inlet
Inferior: diaphragm
Lateral: pleura

Question 5

What organs/vessels/nerves are within the middle of the mediastinum?

Answer 5

Heart
Pericardium
Great vessels
phrenic nerves

Question 6

What organs/vessels/nerves are within the superior portion of the mediastinum?

Answer 6

Trachea
esophagus
Great vessels
Vagus nerves
Thoracic duct
Thymus

Question 7

What organs/vessels/nerves are within the posterior portion of the mediastinum?

Answer 7

Esophagus, descending aorta, vagal trunks, azygos and hemiazygos nerves

Question 8

What organs/vessels/nerves are within the anterior portion of the mediastinum?

Answer 8

Thymus and lymph nodes

Question 9

The superior mediastinum contains what 7 things?

Answer 9

Aortic arch
Superior vena cava
Esophagus & trachea
Thoracic duct
Vagus & phrenic nerves
Thymus gland
Azygos vein

Question 10

The aortic arch is a continuation of ___ as it leaves the heart

Answer 10

ascending aorta

Question 11

___ is a remnant of ductus arteriorsis

Answer 11

Ligamentum arteriosum

Question 12

What are the 3 branches of the aortic arch?

Answer 12

Brachiocephalic trunk
Left common carotid artery
Left subclavian artery

Question 13

What does the brachiocephalic trunk subdivide into?

Answer 13

Right subclavian artery & right common carotide

Question 14

What combines to form the superior vena cava?

Answer 14

R & L brachiocephalic vein

Question 15

What are the brachiocephalic veins?

Answer 15

Internal thoracic, vertebral, inferior thyroid, highest intercostal vein

Question 16

Deoxygenated or oxygenated blood goes into the superior vena cava

Answer 16

Deoxygenated

Question 17

Where does the superior vena cava lie?

Answer 17

lies on R side of mediastinum anterolateral to trachea & posterolateral to ascending aorta

Question 18

Esophagus location

Answer 18

runs posterior to trachea, anterior to bodies of vertebra, posterior to L principal bronchus

Question 19

Trachea location

Answer 19

between aorta & esophagus

Question 20

Thoracic duct originates in the ___ and ascends through ___ and terminates at ___

Answer 20

Originates in abdomen & starts above diaphragm in a structure called cysterna chyli

Ascends through both posterior & superior mediastinum

Terminates at L subclavian & internal jugular veins

Question 21

Vagus & phrenic nerve location

Answer 21

Neck

Question 22

The R & L vagus nerve branches to ___.
What does the R recurrent laryngeal nerve loop around & ascend into?
What does the L recurrent laryngeal nerve loop around & ascend into?

Answer 22

Branches to pulmonary, esophageal & cardiac plexuses

R recurrent laryngeal nerve - loops around subclavian artery & ascends into neck to innervate larynx

Left recurrent laryngeal nerve - loops around aortic arch & ascends into neck to innervate larynx

Question 23

Phrenic nerves come off of what roots?

Answer 23

3, 4, 5

Question 24

What’s significant about the thymus gland?

Answer 24

It shrinks after puberty

Question 25

The posterior mediastinum contains the

Answer 25

Descending aorta Azygos vein Homizygos vein Thoracic duct Esophagus Phrenic nerves Vagus nerves Splanchnic nerves

Question 26

Where does the descending aorta begin, where's its location?

Answer 26

Begins at lower border of T4 (at level of sternal angle) Located posterior to diaphragm

Question 27

What are the branches of the descending aorta?

Answer 27

Bronchial artery Posterior intercostal artery Subcostal artery Esophageal artery Phrenic (superior) artery

Question 28

The azygos vein is formed by the junction of the. Where does it end?

Answer 28

- R subcostal & R ascending lumbar veins - Ends in lower part of superior vena cava

Question 29

The azygos vein receives tributaries from

Answer 29

R posterior intercostal vein R superior costal V

Question 30

The accessory homizygos vein is formed by the union of

Answer 30

3 or 4 posterior intercostal veins above T8

Question 31

The homizygos vein is formed by the junction of ___. It ends around ___

Answer 31

L subcostal & L ascending lumbar veins Ends around T8 by crossing to R & joining azygos vein

Question 32

The homizygos vein receives tributaries from

Answer 32

L posterior intercostal veins below T8 Accessory hemiazygos vein

Question 33

The upper 1/3 is ___ & lower 2/3 is ___ in the esophagus

Answer 33

Voluntary Involuntary

Question 34

Where does the esophagus lie? What does it have a close relationship with?

Answer 34

Lies posterior to trachea & aorta in superior mediastinum & a bit to R of midline Has close relationship w/ vagus, cervical, & thoracic sympathetic trunk

Question 35

The vagus nerves lie behind the

Answer 35

Principal bronchi

Question 36

In the esophageal plexus, ___ lie in the upper 1/3 & ___ lie in the lower 2/3

Answer 36

Voluntary motor fibers Autonomic fibers

Question 37

What are the vagal trunks? What lies in the anterior & posterior portion?

Answer 37

R & L nerves come together Anterior = primarily from L vagus Posterior = primarily from R vagus

Question 38

What are splanchnic nerves? Where are the greater, lesser, & lowest splanchnic located?

Answer 38

Preganglionic sympathetic fibers that pass through diaphragm to abdominal viscera Greater = T5-T10 Lesser = T9-T11 Lowest = T12 or last

Question 39

The sympathetic trunk is part of what nervous system?

Answer 39

Autonomic nervous system

Question 40

In the splanchnic nerves, ganglia communicate w/ intercostal nerves via

Answer 40

rami communications (gray & white)

Question 41

Trosier's sign is accompanied by

Answer 41

weight loss & vomiting