superior and middle mediastinum prep

Question 1

where is the superior mediastinum

Answer 1

lie above a plane joining sternal angle to lower border of thoracic vertebrae

Question 2

where is the inferior mediastinum

Answer 2

extends from the plane of sternal angle = T4 to diaphragm

it is subdivided

Question 3

3 parts of the inferior mediastinum

Answer 3

anterior - lies between sternum and pericardium
middle - composes of pericardial sac and contents
posterior - behing the pericardium, extend inferiorly between diaphragm and posterior chest wall

Question 4

what is the fibrous pericardium

Answer 4

collagenous layer fused with central tendon of diaphragm and adventitia of great vessels

Question 5

adventitia

Answer 5

outermost connective tissue covering the vessel

Question 6

serous pericardium

Answer 6

parietal layer - lines the fibrous pericardium and visceral layer - lines outer surface of the heart
provide heart with friction free surface to accommodate its sliding movements

Question 7

pericardial cavity

Answer 7

space between parietal and visceral layers containing serous fluid

Question 8

where does the ascending aorta leave

Answer 8

the LV

Question 9

where does the pul trunk leave

Answer 9

RV

Question 10

describe the path of the aorta

Answer 10

continues as the arch of aorta

curves posteriorly and to L over R pul artery

Question 11

when does the aorta become the descending thoracic aorta

Answer 11

reaches the L side of T4

Question 12

where is the brachiocephalic vein

Answer 12

lies behind the manubrium

anterior to aortic arch

Question 13

what forms the superior vena cava

Answer 13

R and L brachiocephalic veins

Question 14

veins in the neck area

Answer 14

brachiocephalic vein meets subclavian vein which drains arms, and jugular veins that drains head

Question 15

where does azygos vein go

Answer 15

arches forward over root of R lung to enter superior vena cava
drains posterior and lateral parts of thoracic cage

Question 16

what protects the great vessels other than the inf vena cava

Answer 16

manubrium

Question 17

branch of the aortic arch

Answer 17

brachiocephalic artery - crosses over the right side of the trachea
divides into R subclavian artery - pass laterally over 1st rib - enters axilla and R common carotid artery that ascends into the neck to R of trachea
next branch = L common carotid artery - into neck L of trachea
L subclavian artery - into axilla
thyroidea ima artery - may run from arch to thyroid but inconsistent

Question 18

branches in the aorta

Answer 18

brachiocephalic artery - trunk
left common carotid
left subclavian artery

Question 19

what is anterior to the superior vena cava

Answer 19

1st costal cartilage

Question 20

level of bifurcation of the trachea

Answer 20

T4/5

Question 21

what lies in the subcarinal angle

Answer 21

lymph nodes

Question 22

what does the anterior mediastinum contain

Answer 22

strands of thymus and adipose tissue

Question 23

what are the 2 pockets of the pericardial cavity called

Answer 23

pericardial sinuses

Question 24

describe the oblique sinus

Answer 24

blindly ending pocket of pericardial sac

posterior to LA and surrounded by 4 pul veins

Question 25

describe the transverse sinus

Answer 25

between great arteries and SVC

pericardium lined tunnel

Question 26

what happens when you bleed into the pericardial sac

Answer 26

cardiac tamponade
compress the heart
keep it from pumping as well as it should

Question 27

phrenic nerve

Answer 27

supplies sensory nerves to fibrous pericardium, diaphragmatic pleura and peritoneum
terminate in diaphragm

Question 28

path of vagus nerve

Answer 28

from carotid sheath
to neck in thorax
then posterior to lung roots to oesophagus
then form network (the oesophageal plexus)

Question 29

what does the recurrent laryngeal nerve do

Answer 29

supplies skeletal muscle and sensation in the larynx

Question 30

where does the laryngeal nerve go

Answer 30

leaves the L vagus at aortic arch

hook under acrh - run up to larynx in groove between trachea and oesophagus

Question 31

difference between the L and R recurrent laryngeal nerves

Answer 31

r in neck
L inn thorax
both down groove between oesophagus and trachea and enter larynx

Question 32

position of the heart

Answer 32

2/3 lies to L of mid sternal line
1/3 lies to the R
pericardial sac attached to diaphragm

Question 33

cardiac dullness

Answer 33

area of cardiac dullness - triangle at front of chest - heart not covered by lungs

Question 34

what is the apex beat

Answer 34

pulsation - caused by apex of L ventricle of heart when forced against anterior chest wall in contraction

Question 35

where is the apex beat

Answer 35

may be in 4th ICS - children
5th - adults
6-10cm from midsternal line

Question 36

how should patient be to take apex beat

Answer 36

sit on edge of bed

Question 37

which side do you start palpating the apex beat

Answer 37

lateral side - move anteriorly