Mediastinum

Question 1

pulmonary cavities

Answer 1

lateral, lie on either side of the mediastinum

Question 2

mediastinum and divisions

Answer 2

central compartment
superior
inferior
inferior has 3 - anterior middle and the posterior

Question 3

superior mediastinum

Answer 3

from oblique plane through jugular notch and T1 vertebrae (superiorly) to a horizontal plane through the sternal angle and T4/T5 intervertebral disc (iv) inferiorly
ends at the sternal angle

Question 4

inferior mediastinum

Answer 4

from sternal angle and T4/T5 (IV disc) superiorly to the diaphragm inferiorly

Question 5

Thymus

Answer 5

Superior and anterior mediastinum
most anterior structure in the superior mediastinum as it is immediatley deep to the manubrium
primary lymphoid organ
Begins atrophy after puberty

Question 6

Great vessels (arteries and veins) 
just list them

Answer 6

Great arteries

1. Arch of aorta
2. Brachiocephalic trunk
3. left common carotid
4. left subclavian (left because heart is offset to the left)

Great veins
R and left brachiocephalic veins
Superior vena cava

Question 7

aortic arch is a continuation of…

and describe its region

Answer 7

continuation of ascending aorta
begins at the level of the sternal angle (2nd sternocostal joint)
ascends anterior to RIGHT pulmonary artery and trachea (before going posterior)
continuous with the descending thoracic aorta (which passes posterior to root of left lung)

Question 8

aortic arch branches

Answer 8

brachiocephalic trunk (1st branch) - Right common carotid
Right subclavian
left common carotid - 2nd branch
left subclavian- 3rd branch

Question 9

branches of the brachiocephalic trunk

Answer 9

right common carotid

right subclavian

Question 10

T/F the aortic arch is anterior to the right pulmonary artery but posterior to the left pulmonary artery

Answer 10

TRUE

Question 11

what forms the right and left brachiocephalic veins and what do they unite to form?

Answer 11

The right and left brachiocephalic veins are from the union of the right and left subclavian and internal jugular vein

they will form the superior vena cava -drain into heart

Question 12

SVC is fromed at what level from what

where does it end?

Answer 12

Superior vena cava is formed at the level of the first costal cartilage (in superior mediastinum) and then descends at level of 3rd costal cartilage
(*passes into the middle mediastinum at sternal angel/2nd costal cartilage)
The SVC is formed from the right and left brachiocephalic veins which are formed from the R and L internal jugular vein and the R and L subclavian vein

Question 13

function of SVC

Answer 13

returns blood from structures superior to the diaphragm

except the heart and lungs

Question 14

left recurrent laryngeal nerve

Answer 14

as left vagus nerve passes anterior to the aortic arch it gives off the left recurrent laryngeal nerve- it passes around the aortic arch, before ascending between the trachea and esophagus to reach the larnyx

Question 15

location of vagus in the superior mediastinum

Answer 15

anterior to the aortic arch

Question 16

location of vagus in realtion to lung

Answer 16

posteiror - now in the posterior mediastinum

Question 17

vagus contributions

Answer 17

pulmonary plexus (lungs)
inferiorly to esophageal plexus
anterior to vagus trunk (main)

Question 18

right vagus nerve contribution to the vagal trunk

Answer 18

posterior vagal trunk (left vagus does more anterior vagal trunk)

Question 19

course of right vagus

Answer 19

in superior will descend posterior to the superior vena cava and along the right margin of the trachea and will pass to the posterior aspect of the lung (posteiror mediastinum)

Question 20

what level do the esophagus and trachea originate at?

Answer 20

C6

Question 21

what level does the esophagus end

Answer 21

T11- goes out of the diapgragm at t10

Question 22

when does the trachea end?

Answer 22

at the sternal angle- so does not pass into the inferior mediastinum

Question 23

thoracic duct drains?

Answer 23

conveys most lymph of body to venous system except Right upper quadrant - right neck, upper extremity

Question 24

extension of the thoracic duct

Answer 24

from t12 at the cistyerni chyli to the neck

Question 25

important branches off of the thoracic aorta

Answer 25

superior phrenic arteries 
posterior intercostal arteries
esophogeal arteries
bronchial arteries 
pericardial branches

Question 26

posterior mediastinum

Answer 26

portion of thoracic duct (rest in superior) - goes from t12 up into neck at the junction of the internal jugular vein and the left subclavian
esophagus + plexus
thoracic aorta -after arch to t12
azygous and hemiazygous
sympathetic chain (thoracic portion)
greater, lesser, and least splanchnic nerves

Question 27

sensory innervation of the phrenic nerve

Answer 27

sensory to the pericardium, mediastinal pleura, and the disphragm

Question 28

course of the phrenic nerves in the superior mediastinum

Answer 28

anterior to the subclavian arteries and posterior to the subclavian veins - then enter the superior mediastinum

Question 29

course of pericardiacophrenic vessels

Answer 29

these travel with the phrenic nerves and with the phrenic nerves will take an anterior course over the lungs and descend into the middle mediastinum BETWEEN THE FIBROUS PERICARDIUM AND THE MEDIASTINAL PLEURA

Question 30

Contents of the anterior mediastinum

Answer 30

thymus
lyphatic vessels and lymph nodes
mediastinal branches of the internal thoracic vessels
loose connective tissue
smallest subdivision
sternum - anterior with pericardium posteriorly