The Mediastinum

Question 1

what are the boundaries of the mediastinum

Answer 1

superior thoracic aperture
inferior thoracic aperture
sternum
thoracic vertebrae

Question 2

what vertebral level is the transthoracic plane and what does this divide

Answer 2

the transthoracic plane is an imaginary line b/w vertebral bodies T4/T5 that divides the mediastinum into superior and inferior sections

Question 3

what structures pass through the superior mediastinum

Answer 3

PVT Left BATTLE
Phrenic nerve
Vagus nerve
Thoracic ducts
left recurrent laryngeal nerve
Brachiocephalic veins
aortic arch and branches (L. CCA, L. subclavian, brachiocephalic trunk)
Trachea
Thymus
Lymph node
Esophagus

Question 4

how is the inferior mediastinum further divided?

Answer 4

into anterior, middle and posterior sections

Question 5

what are the contents of the anterior mediastinum? what are its boundaries?

Answer 5

inferior thymus, fat, lymph nodes
bounded by the parietal pleura, diaphragm and sternal angle

Question 6

what are the main structures in the middle mediastinum

Answer 6

the heart and pericardium

Question 7

what are the contents of the posterior mediastinum

Answer 7

the inferior esophagus, thoracic aorta, azygos and hemiazygos veins

Question 8

what are the branches of the ascending aorta

Answer 8

right and left coronary arteries

Question 9

what are the branches of the aortic arch

Answer 9

brachiocephalic trunk
left common carotid artery
left subclavian artery

Question 10

what are the branches of the brachiocephalic trunk

Answer 10

the right common carotid artery
the right subclavian artery

Question 11

what contributes to form a brachiocephalic vein?

Answer 11

the internal jugular vein and the subclavian vein

Question 12

what joins to form the SVC

Answer 12

The left and right brachiocephalic veins

Question 13

where does the SVC drain?

Answer 13

into the right atrium

Question 14

what two veins form the IVC

Answer 14

the left and right common iliac veins

Question 15

give a brief description of azygos venous system

Answer 15

they are a collateral circulation b/w the IVC and SVC, they drain blood from pericardium, the posterior thoracic wall and bronchi.
hemiazygos on the left, azygos on the right, hemi drains into azygos, azygos drains into SVC

Question 16

where does the pulmonary trunk arise from?

Answer 16

the right ventricle

Question 17

what are the branches of the pulmonary trunk

Answer 17

left and right pulmonary arteries, they carry deoxygenated blood to the lungs for CO2 exchange for O2

Question 18

what do the pulmonary veins carry and where do they drain

Answer 18

they carry oxygenated blood from the lungs and drain into the left atrium

Question 19

describe the course of the right recurrent laryngeal nerve

Answer 19

this arises from the r. vagus nerve, anterior to the r. subclavian artery, hooks around this artery and ascends b/w trachea and esophagus to supply the larynx

Question 20

describe the course of the left recurrent laryngeal nerve

Answer 20

branch of the l. vagus nerve at inferior border of the aortic arch, passes inferiorly to the arch, ascends b/w trachea and esophagus to supply the larynx

Question 21

what are the spinal roots of the phrenic nerve

Answer 21

C3, C4, C5

Question 22

what is the position of the phrenic nerve relative to the vagus nerve

Answer 22

the phrenic nerve runs laterally to the vagus nerve

Question 23

what are the two layers to the serous pericardium

Answer 23

parietal and visceral

Question 24

what are the atrioventricular valves

Answer 24

tricuspid on the right, mitral or bicuspid on the left

Question 25

what are the semilunar valves

Answer 25

aortic and pulmonary valves

Question 26

what does the aortic valve separate

Answer 26

the Left ventricle and the ascending aortaw

Question 27

what does the pulmonary valve separate

Answer 27

the right ventricle and the pulmonary trunk

Question 28

what is the relationship between the sulcus terminalis and the crista terminalis

Answer 28

the sulcus terminalis is on the external surface of the RA the crista terminalis is on the internal surface of the RA

Question 29

What chamber are the pectinate muscles located in

Answer 29

the RA

Question 30

what are the chordae tendineae extensions of

Answer 30

they are extensions of the atrioventricular valve

Question 31

what is the attachment of the chordae tendineae

Answer 31

to the papillary muscles

Question 32

what are the trabeculae carneae

Answer 32

they are irregular muscular ridges in the ventricles

Question 33

what is the significance of the semilunar cusps of the aortic valve?

Answer 33

the right cusp gives rise to the right aortic sinus which branches into the Right coronary artery the left cusp gives rise to the left coronary sinus which branches into the left coronary artery the posterior cusp is the aortic sinus

Question 34

what are the branches of the right coronary arteries

Answer 34

the posterior interventricular artery the right marginal artery sinoatrial nodal branch

Question 35

what are the direct branches of the left coronary artery

Answer 35

the anterior interventricular artery (LAD) the left circumflex artery

Question 36

name the branch of the LAD

Answer 36

diagonal branches

Question 37

name the branch of the left circumflex artery

Answer 37

left marginal

Question 38

what coronary artery does the great cardiac vein run with

Answer 38

the left anterior descending artery

Question 39

what coronary artery does the middle cardiac vein run with

Answer 39

the posterior interventricular artery

Question 40

what coronary artery does the small cardiac vein run with

Answer 40

the right marginal artery

Question 41

where do the cardiac veins drain

Answer 41

into the coronary sinus on the posterior heart surface

Question 42

what is meant by diastole

Answer 42

blood flows from major veins into the atria, then blood flows PASSIVELY into the ventricles

Question 43

what is meant by atrial systole

Answer 43

when the atria contract to completely fill the ventricles

Question 44

what is meant by ventricular systole

Answer 44

ventricles contract to push blood out of the heart