EXAM3_G23_Superior_Posterior_Mediastinum

Question 1

Order of 6 major structures from Anterior to Posterior of the superior mediastinum

This should be your mental checklist:

TGGTEL

Answer 1

1. Thymus
2. Great Veins
3. Great Arteries
4. Trachea
5. Esophagus
6. Lymphatics (mainly posterior)

Question 2

What arteries supplies blood to the thymus?

Answer 2

1. Internal thoracic artery

2. Anterior intercostal Arteries

Question 3

Where does blood drain from the thymus?

Answer 3

1. Left brachiocephalic vein
2. Internal thoracic vein
3. Inferior thyroid vein

Question 4

What does lymph from thymus drain to?

Answer 4

1. Parasternal nodes
2. Brachiocephalic nodes
3. Tracheobronchial nodes

Question 5

What drains lymph into the thymus?

Answer 5

NOTHING! - no afferent lymphatics for thymus

Question 6

What drains blood from head neck and upper limbs into the right atrium?

Answer 6

Brachiocephalic Veins (LEFT IS LONGER)
-

Question 7

What is the point called where the jugular vein and subclavian vein combine to form the LR brachiocephalic vein

Answer 7

LR Venous Angles

Question 8

Blood from all structures superior to diaphragm (except heart and lungs) drain into the ?

Answer 8

SUPERIOR VENA CAVA

Question 9

The Transverse thoracic plane is a landmark for what feature of the heart?

Answer 9

Base of arch of the Aorta

ascending and descending shows at this level on radiograph

Question 10

In an AP radiograph- At the transverse thoracic plane- the aorta ascends anterior to the ________ and ____. It arches over and posterior to the _______. and Descends ___ of midline

Answer 10

ascends anterior to right pulmonary artery and tracheal bifurcation.

Arches over and posterior to root of the lung and descends LEFT of midline

Question 11

What two landmarks that your looking at the Descending aorta on radiograph (at transverse thoracic plane)

Answer 11

1. Left midline deviation

2. Posterior to root of the lung

Question 12

Blood bypasses the ______ circuit in a fetus via a shunt called the_____ which becomes the ____ _______ after birth. This forms between the ______ and the _____,

Answer 12

Pulmonary Circuit via the Ductus Arteriosus

which becomes the ligamentum arteriosum which forms between the LPA and Aortic Arch

Question 13

The transverse thoracic plane is a landmark for what feature of the trachea?

Answer 13

Ends at the transverse thoracic plane by branching into right and left main bronchi

Question 14

What are two Keys that define you’re looking at the Trachea at the TTP level of a radiograph?

Answer 14

1. widening/bifurcation
2. slight right deviation
3. anterior to esophagus
4. posterior to aortic branches

Question 15

Vagus and phrenic nerve which is anterior/posterior to ROL?

Answer 15

VP- Posterior ROL is Vagus (with Left recurrent laryngeal n)

AP- anterior ROL is PHRENIC

Question 16

LEFT recurrent laryngeal nerve located? and innervates?

Answer 16

Hooks medially under AORTIC ARCH superiorly to innervate laryngeal muscles

Question 17

RIGHT recurrent laryngeal nerve located?

Answer 17

Hooks posteriorly under right SUBCLAVIAN artery superiorly to innervate laryngeal muscles

Question 18

5 Components of the Posterior mediastinum

Answer 18

1. Thoracic Aorta
2. Thoracic Duct
3. Azygos system of veins
4. Esophagus
5. Nerves

Question 19

What are the Vertebral levels of the posterior mediastinum?

Answer 19

Posterior (means inferior mediastinum) Under TTP-

T5 - T12

Question 20

What are the branches of the Thoracic Aorta?

Answer 20

1. Bronchial aa
2. Esophageal aa (ribs 2-5)
3. Posterior Intercostal aa (ribs 3-11)- anast w/ Ant Intcstls
4. Subcostal aa. 1 pair inferior to rib 12

Question 21

Esophageal aa are found at what rib levels of the thoracic aorta?

Answer 21

ribs 2-5 (unpaired)

Question 22

Posterior intercostal arteries (9 pairs) course inferior to ribs ? What do they anastomose with?

Answer 22

3-11

anastomose with Anterior intercostal aa

Question 23

Subcostal aa (1 pair) run inferior to rib ?

Answer 23

12

Question 24

Esophagus runs ____ of the thoracic aorta

Answer 24

Right

Question 25

What are the three points of compression of the esophagus?

Answer 25

1. Cervical constriction 2. Thoracic constriction (Aorta/Trachea) 3. Diaphragmatic constriction

Question 26

What drains into the azygous veins? | What is a unique feature about these veins?

Answer 26

Thoraco-abdominal walls Mediastinal structures - NO VALVES -Communicates with vertebral venous plexuses

Question 27

Azygous veins can communicate with the vertebral venous plexus. This is one pathway for cancer to spread from where to where??

Answer 27

From thoracic wall & Viscera to the CNS

Question 28

Azygous vein Transverses along the ____ side of the thoracic vertebrae and provides collateral pathway between the ____ and _____ and joints the SVC at the ______.

Answer 28

RIGHT side of vertebrae | SVC & IVC and joins SVC at TTP.

Question 29

Hemiazygous vein courses on ___ side of thoracic vertebrae and usually at ____ turns medially to drain into the _____vein.

Answer 29

Left at T9, drains into Azygous vein

Question 30

Acessory hemiazygous vein courses ____ of thoracic ver. usually at ____ vert level turns medially and drains into the ____. vein . sometimes it connects to ______.

Answer 30

Left of TV, usually at T8 turns medial drains into Azygous | Sometimes connects to hemiazygous v.

Question 31

Thoracic duct courses superiorly on the ____ side of the thoracic vertebrae and switches to the ___ side at ___ to ___ vert levels

Answer 31

Right side, switches to left side at t4-t6 vertebral levels

Question 32

The thoracic duct returns lymph to venous circulation where?

Answer 32

at Left venous angle

Question 33

Posterior Mediastinal Lymph nodes filter lymph from 4 places?

Answer 33

1. esophagus 2. posterior pericardium 3. diaphragm 4. posterior intercostal space

Question 34

Esophagus, posterior pericardium, diaphragm, and posterior intercostal space drain their lymph into?

Answer 34

Posterior mediastinal lymph nodes

Question 35

Sympathetic trunks

Answer 35

Bilateral chain of paravertebral ganglia

Question 36

Sympathetic trunks supply sympathetic innervation to viscera of body wall & cavities (sweat glands, arector pili). the thoracic portion gives rise to ____. nerves

Answer 36

abdominopelvic splanchnic nn. White/Gray RC- >ParaVert ganglion- >abdominopelvic splanchnic nn

Question 37

Abdominopelvic splanchnic nerves- where do they arise? what do they innervate?

Answer 37

Three bilateral pairs of abdominopelvic splanchnic nerves originate in the thorax and supply sympathetic innervation to viscera inferior of the diaphragm.

Question 38

Vert level for Greater splanchnic Nerves

Answer 38

T5-T9

Question 39

Vert level for Lesser splanchnic Nerves

Answer 39

T10-T11

Question 40

Vert level for Least splanchnic nerves

Answer 40

T12

Question 41

4 contents of anterior mediastinum

Answer 41

1. Adipose/thymus 2. Internal thoracic aa/vv 3. Anterior intercostal aa/vv 4. Parasternal nodes