Lecture 15 - Superior and Posterior Mediastinum

Question 1

What separates the the post/ant mediastinum from the superior mediastinum

Answer 1

The bottom of the manubrium

Question 2

What distinguishes the ant/post mediastinum and inferior

Answer 2

Top of the xiphoid process

Question 3

What spinal segments are associated with the posterior mediastinum

Answer 3

T5-12

Question 4

Where is the jugular notch

Answer 4

T2 in men and T3 in women

Question 5

What joins to form the brachiocephalic vein

Answer 5

Subclavian and internal jugular

Question 6

At what level is the trachea bifurcation and the beginning of the aortic arch

Answer 6

T4

Question 7

Where do the phrenic nerves run in relation to the lung

Answer 7

Anterior

Question 8

Where does the vagus nerve run

Answer 8

Posterior

Question 9

What does the left recurrent laryngeal nerve go

Answer 9

Hooked around the ligamentum arteriosum

Question 10

What nerves are involved in MI

Answer 10

Cardiac pain via left sympathetic nn and BP and O2 sensors via vagus n

Question 11

What are the branches supposed to be off of the aortic arch

Answer 11

1. Brachiocephalic trunk branches into R common carotid and R subclavian
2. L common carotid
3. L subclavian

Question 12

What do the brochial AA supply

Answer 12

They go into the hilum of the lungs and supply primary, secondary, and tertiary brochioles

Question 13

What do superior phrenic A supply

Answer 13

Diaphragm

Question 14

What drains the R posterior thorax

Answer 14

Azygos v

Question 15

Where is the hemiazygos v

Answer 15

Below T9 on the left side where it crosses behind the esophagus and dumps into azygos v

Question 16

What are the branches of the internal thoracic A

Answer 16

Pericardiacophrenic A
Superior epigastric A (terminal)
Musculophrenic A (terminal)

Question 17

What does the thoracic aorta give rises to

Answer 17

Superior phrenic AA

Question 18

What are the 3 parts of the esophagus

Answer 18

Cervical (C6-T1)
Thoracic (T1-diaphragm hiatus)
Abdominal

Question 19

What does the esophagus pierce

Answer 19

Left posterior diaphragm

Question 20

What are the common constriction sites for the esophagus

Answer 20

Cricopharyngeus muscle in cervical region (C6)
Aortic arch (T4)
Left bronchus
Diaphragm (T10)

Question 21

Around the esophagus what nerve travels laterally? Where does it end up

Answer 21

Vagus N.

The L Vagus goes anterior
R Vagus goes posterior

Question 22

At what levels are the greater splanchnic NN

Answer 22

T5-9 presynaptic sympathetic fibers

Pass anteriorly through the diaphragm to relay in celiac ganglion

Question 23

What level are the lesser splanchnic nn

Answer 23

T10-11

Question 24

Where are the least splanchnic nn

Answer 24

T12

Question 25

What are thoracic splanchnic nn

Answer 25

Sympathetic presynaptic ganglion

Question 26

What are the gray communicans

Answer 26

Unmyelinated neurons

Question 27

What are white rami

Answer 27

Myelinated neurons

Question 28

Where does the right thoracic duct dump into

Answer 28

Right subclavian v

Question 29

Where does the thoracic duct dump into

Answer 29

L subclavian V

Question 30

Where does the thoracic duct run

Answer 30

Between azygos v and descending aorta

Question 31

Where does the thoracic duct terminate

Answer 31

Near the junction of the internal jugular v and subclavian v

Question 32

What can impinge on the vagus n

Answer 32

Mediastinal lymph nodes (lung cancer)

Question 33

Impinging on the left recurrent laryngeal n can cause

Answer 33

Hoarseness which can disrupt speech

Question 34

What keeps the ductus arteriosus open during development

Answer 34

Prostaglandins

Question 35

What normally causes the ductus arteriosus to close

Answer 35

Changes in o2 tension and blood flow decrease prostaglandin levels which cause SM to contract around 10-15H

Question 36

What are the consequences of PDA

Answer 36

LV hypertrophy with pulmonary congestion and congestive heart failure

Question 37

What causes an increased risk of PDA

Answer 37

Maternal rubella infection

Question 38

Where do we see more coarctation

Answer 38

Turner’s syndrome

Question 39

What is an aberrant origin of the right subclavian

Answer 39

Doesn’t come off brachiocephalic trunk instead comes off on the left most position and comes behind the esophagus

Question 40

What can occur with the R aortic arch

Answer 40

It can persist after development causing a double aortic arch

Question 41

Where are interrupted aortic arches more common

Answer 41

DiGeorge Syndrome

Question 42

What is a disrupted aortic arch

Answer 42

The left and right aortic arches degenerate so the L and R trunks are separate

Question 43

Where do the common carotid come from

Answer 43

The third aortic arch

Question 44

Where does the mature aortic arch come from

Answer 44

L 4th aortic arch

Question 45

Where does the left subclavian come from

Answer 45

7th intersegmental aortic arch

Question 46

What does the left recurrent laryngeal n get hooked to

Answer 46

Ligamentum arteriosum

Question 47

The R recurrent laryngeal gets hooked to the

Answer 47

R subclavian A

Question 48

Is preductal coarction or postductal worse?

Answer 48

Preductal, b/c postductal can still provide blood via collateral system through the L subclavian A which then connects to the internal thoracic A and intercostal A to the lower limb

Question 49

What can an aberrant R subclavian cause

Answer 49

Dysphagia since it wraps around the esophagus posteriorly