Thorax 4

Question 1

what does the mediastinum contain

Answer 1

all thoracic structures apart from lungs and surrounding pleura

Question 2

how is the superior mediastinum and inferior mediastinum separated?

Answer 2

there is a horizontal plan at level between T4 and T5 and the sternal angle of sternum (also at birufication of trachea)

Question 3

what is in the superior mediastinum?

Answer 3

-thymus (also in anterior mediastinum)
-SVC and 2 great veins
-arch of aorta
-trachea
-oesophgus
-thoracic duct -> lymphatic trunks-> subclavian veins

Question 4

why is one brachiocephalic vein longer than the other

Answer 4

left is longer than right due to left-> right venous shunting where the superior vena cava sits slightly to the right

Question 5

how is the superior mediastinum bound?

Answer 5

superiorly: superior thoracic aperture
inferiorly: sternal angle-> transverse thoracic plane
anteriorly: bound by manubrium
posteriorly: bound by first 4 vertebrae

Question 6

what are the nerves innervating the heart

Answer 6

-right and leftvagus nerve-> vagal cardiac branches
-cardiac nerves from sympathetic trunk-> superficial cardiac plexus (sort of under aortic arch)

Question 7

what is in the most anterior part of posterior mediastinum

Answer 7

-descending thoracic aorta
-oesophagus

Question 8

most posterior structures of the inferior mediastinum

Answer 8

-azygos system of veins
-thoracic duct
-sympathetic trunks on either side of vertebral column

Question 9

when does the descending thoracic aorta start?

Answer 9

continuation of arch of aorta (which is in the superior mediastinum) and starts at T5

Question 10

what does the thoracic aorta do?

Answer 10

-gives off mediastinal branches (and more) which supplies things such as the lymph nodes of posterior mediastinum
-supplies the posterior intercostal arteries

Question 11

what are the branches of the vagus nerve on the oesophagus called?

Answer 11

oesophageal plexus- innervates oesophagus

Question 12

what do the mediastinal branches of aorta supply?

Answer 12

lymph nodes

Question 13

what do the pericardial branches of the thoracic aorta supply?

Answer 13

posterial aspect of pericardium of heart

Question 14

oesophageal branch of thoracic aorta supplies the?

Answer 14

oesophagus

Question 15

what does the oesophageal plexus of vagus nerve converge into?

Answer 15

the anterior vagal trunk (left vagus nerve) and posterior vagual trunk (right) (on anterior and posterior surfaces of oesophagus)

Question 16

what side of the oesophagus is the thoracic aorta on

Answer 16

left side

Question 17

when do the superior phrenic arteries branch off?

Answer 17

right before thoracic aorta passes through aortic hiatus

Question 18

what does the superior phrenic arteries supply?

Answer 18

the superior aspect of the diaphragm

Question 19

where does the azygous vein sit?

Answer 19

right hand side on thoracic verterbral bodies

Question 20

other than the left brachiocephalic vein, what other vein shows left-> right venous shunting?

Answer 20

hemiazygous vein

Question 21

how is the azygous vein formed?

Answer 21

uniting the right ascending lumbar vein and right subcostal vein quite low down

Question 22

azygous vein function

Answer 22

drains majority of posterior intercostal veins (T1-T2 first intercostal space drained by supreme intercostal vein)

Question 23

hemiazygos vein role

Answer 23

responsible for draining intercostal spaces from 9th intercostal space-> last intercostal region 11
(accessory hemiazygos does 4-8-> left side be dif ig cah right side azygous 2-11 w/ siv for 1)

Question 24

what is the only intercostal space that isnt drained by azygos veins and what does it drain into

Answer 24

T1-T2 first intercostal space drained by supreme intercostal vein into left
and right brachiocephalic vein

Question 25

at what level does the azygous vein unite with superior vena cava

Answer 25

at level of sternal angle (between t4 and t5)

Question 26

what is the accessory hemiozygos vein?

Answer 26

branch above the hemiozygous vein of the azygos vein that drains the left posterior intercostal veins 4-8

Question 27

drainage of the cisterna chyli

Answer 27

penultimate drainage point for all of the lymmph below the diaphragm before it is drained by the thoracic duct

Question 28

thoracic duct role

Answer 28

-largest lymphatic duct responsible for draining all lymphatic fluid from entire body except for upper right quadrant into junction between
left internal juglar vein and left subclavian vein

Question 29

splanchic nerves branching

Answer 29

-greater
-lesser
-least

Question 30

where do the splanchic nerves travel?

Answer 30

-travels down through diaphragm to supply the viscera of the abdomen with sympathetic innervation

Question 31

thoracic duct travel

Answer 31

goes over the vertebral bodies then moves off left to drain in junction of left interal juglar vein and left subclavian vein (thoracic duct)

Question 32

describe how the sympathetic trunk travels and what they do

Answer 32

sympathetic efference from T1 to L2 will
-travel up chain into cervical ganglia providing sympathetic innervation
-or go down all the way to sacrum and coccygeal regions to supply pelvis and lower limbs with sympathetic innervation

Question 33

what nerves innervate heart with sympathetic innervation

Answer 33

levels T1-T4 cardiac branches of sympathetic chain