Mediastinum

Question 1

where is sympathetic chain wrt vertebral column?

Answer 1

lateral to vertebral column

Question 2

which side of the mediastinum is the SVC on?

Answer 2

superior vena cava is on right side

Question 3

Describe the course of the esophagus

Answer 3

• originates at C6
• pass from neck to superior mediastinum
• posterior to trachea
• into inferior (posterior) medastintum
• through diaphragm at T10
• ends at T11

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Question 5

descibe borders of anterior mediastinum

Answer 5

continuous with superior mediastinum at sternal angle, bottom is diaphragm, anterior is sternum and posterior is pericardium

Question 6

boundaries of superior mediastinum

Answer 6

from plane through jugular notch and T1 vertebra down to

plane though sternal angle and T4/T5 intervertebral disc

Question 7

where does thoracic aorta begin/end?

Answer 7

• begins at T4/T5 IV disc
• ends at T12 vertebral level at aortic hiatus (to become abdominal aorta)

Question 8

contents of anterior mediastinum

Answer 8

• thymus (extends into anterior mediastinum)
• loose CT and fat
• lymph vessels and lymph nodes
• mediastinal branches of internal thoracic vessels

Question 9

where is thymus

Answer 9

root of neck (superior mediastinum and anterior mediastinum)

immediately deep to manubrium

Question 10

Superior vena cava returns blood from what structures to heart?

Answer 10

returns blood from everything superior to diaphragm except heart and lungs

Question 11

contents of middle mediastinum (13)

Answer 11

1. heart
2. ascending aorta
3. inferior portion of SVC
4. terminal portion of azygous vein
5. primary bronchi
6. pulmonary trunk
7. R and L pulmonary arteries
8. pulmonary veins
9. phrenic nerves
10. pericardiacophrenic vessels
11. cardiac plexus
12. IVC
13. lymph nodes

Question 12

what is azygos sytem of veins?

Answer 12

• longitudinal veins that receive blood from the body wall and mediastinal viscera
• forms collateral pathways between IVC and SVC

Question 13

thoracic duct drains lymph from where?

Answer 13

from all of body except right upper quadrant

Question 14

When the aortic arch is ascending where is it in relation to other structures?

Answer 14

aortic arch ascends anterior to right pulmonary artery and trachea, then goes posterior

Question 15

Trachea and esophagus orginate at what vertebral level?

Answer 15

C6

Question 16

describe path of hemiazygos & accessory hemiazygous veins

Answer 16

normally empty into azygous vein but path is variable

Question 17

What occurs at the indicated spots?

Answer 17

Question 18

Label A-D

Answer 18

A. Sympathetic chain

B. Greater splanchnic nerve

C. Lesser splanchnic nerve

D. Least splanchnic nerve

Question 19

branches of aortic arch

Answer 19

• brachiocephalic trunk (1st branch)
  
  • right common corotid artery
  • right subclavian artery
• left common carotid artery (2nd brach)
• left subclavian artery (3rd branch)

Question 20

describe path of azygos veins

Answer 20

• originates around L1
• enters thorax @ posterior mediastinum via aortic hiatus
• ascends to the right of thoracic duct
• arches over root of right lung to join SVC

Question 21

at what level does the superior vena cava pass into the mediastinum and where does it terminate?

Answer 21

into mediastinum at sternal angle and terminates at level of 3rd costal cartilage

Question 22

inferior mediastinum boundaries

Answer 22

from plane through sternal angle and T4/T5 intervertebral disc down to

diaphragm

further subdivided into anterior, middle, posterior mediastunum

Question 23

describe path of left recurrent laryngeal nerve

Answer 23

• arises from left vagus nerve
• passes around aortic arch before ascending between trachea and esophagus to reach larynx

Question 24

significant branches of thoracic aorta (6)

Answer 24

1. posterior intercostal arteries
2. esophageal arteries
3. bronchial arteries
4. mediastinal branches
5. pericardial branches
6. superior phrenic arteries

Question 25

describe path of thoracic duct

Answer 25

* starts at cisterna chyli (~T12) * ascends through posterior mediastinum posterior to esophagus between descending thoracic aorta and azygous vein * goes left and enters superior mediastinum * ends at junction of left subclavian vein and left IJV (internal jugular vein)

Question 26

describe path of right vagus nerve

Answer 26

* enters superior mediastinum posterior to brachiocephalic vein * descends posterior to superior vena cava and along right margin of trachea * passes posterior to root of lung in posterior mediastinum * branches into pulmonary plexus and inferiorly to esophageal plexus and posterior vagal trunk

Question 27

which 3 thoracic splanchnic nerves course in posterior mediastinum and where are they formed?

Answer 27

1. Greater splanchnic nerve (formed from T5-T9) 2. Lesser splanchnic nerve (formed from T10-T11) 3. Least Splanchnic nerve (formed from T12)

Question 28

Whats the smallest subdivision of the mediastinum?

Answer 28

anterior (inferior) mediastinum

Question 29

where is thoracic aorta wrt esophagus?

Answer 29

thoracic aorta is mostly to the LEFT of the esophagus

Question 30

what are the great veins and what part of the mediastinum are they in?

Answer 30

* right and left brachiocephalic veins * superior vena cava all in superior mediastinum

Question 31

Describe left vagus nerve path

Answer 31

* enters superior mediastinum posterior to left brachiocephalic vein * passes anterior to aortic arch and posterior to root of lung in posterior mediastinum * gives off left recurrent laryngial nerve * branches into pulmonary plexus, inferiorly to esophageal plexus and anterior vagal trunk

Question 32

what joins to form left and right brachiocephalic veins and where do they join?

Answer 32

union of internal jugular veins and subclavian veins occurs posterior to sternoclavicular joint

Question 33

what nerve supplys motor innervation to diaphragm?

Answer 33

phrenic nerve

Question 34

what are the great arteries and what section of the mediastinum are they part of?

Answer 34

* arch of aorta (and proximal portion of its major branches) * brachiocephalic trunk * left common carotid * left subclavian all in superior mediastinum

Question 35

what is the aortic arch continuous with on both sides?

Answer 35

continuous with ascending aorta then continuous with descending thoracic aorta (posterior to root of left lung)

Question 36

what is the primary lymphoid organ?

Answer 36

thymus

Question 37

what unites to form superior vena cava and where does this occur?

Answer 37

left and right brachiocephalic veins join at level of 1st costal cartilage

Question 38

phrenic nerve supplies sensory branches to what?

Answer 38

pericardium, mediastinal pleura, diaphragm

Question 39

describe path of pericardiacophrenic vessels

Answer 39

* travel with phrenic nerves * 3 structures * pass anterior to root of lung and descend through the middle mediastinum between fibrous pericardium and medastinal pleura

Question 40

describe path of phrenic nerve

Answer 40

* originates in neck (C3,4,5) * pass anterior to subclavian artery and posterior to subclavian vein * enter superior mediastinum

Question 41

where does trachea end

Answer 41

ends at sternal angle (before inferior mediastinum)

Question 42

where does arch of aorta start?

Answer 42

begins at level of sternal angle, posterior to 2nd right sternocostal joint (not covered by pericardium)