Heart and mediastinum

Question 1

what are the boundaries of superior mediastinum

Answer 1

superior thoracic apeture to T4-T5

Question 2

what are the contents of the superior mediastinum

Answer 2

• brachiocephalic vein
• arch of aorta
• thoracic duct (drains between internal jugular and subclavian)
• trachea
• oesophagus
• thymus
• vagus nerve
• L recurrent laryngeal
• phrenic

Question 3

Compartments of inferior mediastinum

Answer 3

anterior, middle and posterior

Question 4

boundaries of inferior mediastinum

Answer 4

transverse thoracic plane and diaphragm

Question 5

contents of anterior mediastinum

Answer 5

thymus, lymph nodes and vessels, fat, connetive tissue, sternopericardial ligaments

Question 6

contents and boundaries of middle mediastinum

Answer 6

boundaries: pericardial sac

heart, roots of great vessel, arch of azygous vein, main bronchi

Question 7

contents of posterior mediastinum

Answer 7

oesphagus, thoracic aorta, azygous and hemi azygous, thoracic duct, vagus nerves, sympathetic trunks, splachnic nerve

Question 8

boundaries of pericardial sac

Answer 8

2-6 costal cartilages, T5-T8

Question 9

what does the pericardial sac consist of

Answer 9

fibrous: continuous with diaphragm - fuses with tunica adventitia of great vessels and attached to sternum via sternopericardial ligaments

stops heart overfilling

serous- 2 layers:

parietal-> lines fibrous

visceral-> lines heart = epicardium

Question 10

what is the pericardial cavity

Answer 10

space in between parietal and visceral containing serous fluid to allow for frictionless movement

Question 11

where is the transverse pericardial sinus

Answer 11

posterior to ascending aorta and pulmonary trunk

Question 12

where is the oblique pericardial sinus

Answer 12

a wide recess posterior to heart formed by the serous pericardium which covers SVC, IVC and pulmonary veins

Question 13

arterial supply of pericardium

Answer 13

pericardiocophrenic artery and internal thoracic artery branch

Question 14

venous drainage of pericardium

Answer 14

pericardiocophrenic veins, brachiocephalic

azygous system

Question 15

nerve supply of pericardium

Answer 15

phrenic nerves (sensory)

vagus nerve

sympathetic

Question 16

layers of the heart

Answer 16

1. epicardium (visceral pleura)
2. myocardium- muscle
3. endocardium- thin internal layer covering valves and heart

Question 17

Answer 17

Question 18

Answer 18

Question 19

Answer 19

Question 20

landmarks of apex of heart

Answer 20

posterior to left 5th ICS mid clavicular line

Question 21

landmarks of base of heart

Answer 21

mainly LA, T6-T9

Question 22

contents of anterior surface of heart

Answer 22

RV

Question 23

contents of diaphragmatic surface of heart

Answer 23

LV, some RV

Question 24

contents of L pulmonary surface of heart

Answer 24

LV

Question 25

contents of R pulmonary surface of heart

Answer 25

RA

Question 26

landmarks of border of heart

Answer 26

superior: 2nd LCC-\> 3rd RCC Right: 3rd cc to 6th cc inferior 6th RCC to 5th L ICS mid clavicular L: 5th ICS to 2nd CC

Question 27

what does the RA consist of

Answer 27

* pectinate muscles in wall * SVC opening: 3rd CC * ICS opening 5th CC * fossa ovalis: interatrial septum remnant of oval foramen * right auricle: muscular pounch increases capacity of atrium and overlaps with ascending aorta

Question 28

contents of RV

Answer 28

* trabeculae carnae: muscular ridges * tricupsid valve: posterior to sternum 4-5th ICS * tendinous chords: attach to valve cusps (anterior, posterior and septal) * papillary muscles: attached to wall and chords

Question 29

function of tendinous chords

Answer 29

prevent inversion and seperation of vlaves

Question 30

function of papillary muscles

Answer 30

contract before RV contraction tightens tendinuous chords

Question 31

where is the moderator band and what does it do

Answer 31

IV septum part of R bundle branches to AV bundle to anterior papilary muscle allows for coordinated contraction 'shortcut'

Question 32

landmark of pulmonary valve and number of cusps

Answer 32

3rd costal cartilage 3 semi lunar cusps sinuses prevent valves sticking due to blood

Question 33

contents of left atrium

Answer 33

* valveless R and L pul. veins * L auricle: part of L border contains pectinate muscles * smooth wall: absorption of parts of embryonic pulmonary veins * rough wall: mainly auricle remains of L primordial atrium

Question 34

contents of left ventricle

Answer 34

mitral valve- double leaflet with anterior and posterior cusps posterior to sternum at 4th CC trabeculae carnae: finer and more numerous anterior and posterior papillary muscles- larger

Question 35

aortic sinuses

Answer 35

right drains into right coronary artery left drains into left coronary artery nothing arises from posterior

Question 36

stenosis

Answer 36

failure of valve to open fully

Question 37

valvular insufficiency

Answer 37

failure of valve to close completely- regurgiation

Question 38

function of cardiac skeleton

Answer 38

* dense collagen- four fibrous rings * keeps orifices, AV amd semilunar valves patent prevents over distention * attachment for myocardium * attachment for leaflet and cusps * eletrical insulator- independent contraction of atria and ventricles

Question 39

Answer 39

Question 40

Answer 40

Question 41

what does the right coronary artery supply

Answer 41

RA, SA (2/3), AV nodes 80%, 1/3 posterior part of IV septum

Question 42

what does the left coronary artery supply

Answer 42

most of LA and LV, 2/3 anterior IV septum, AV bundles, may supply AV node 20%

Question 43

Answer 43

Question 44

where is the right recurrent laryngeal

Answer 44

crosses under and posterior to right subclavian artery. ascends lateral to trachea to the larynx