M103 T1 L3

Question 1

What are the boundaries of the middle mediastinum?

Answer 1

anterior: anterior pericardium
posterior: posterior pericardium
lateral: mediastinal pleura
inferior: diaphragm
superior: sternal angle

Question 2

What are the contents of the middle mediastinum?

Answer 2

heart, pericardium
ascending aorta
pulmonary veins, arteries, nerves and trunk (VANT)
(HP.AA.Pvant)

Question 3

What are the structures of the heart chambers?

Answer 3

4 chambers - 2 receiving atria and 2 discharging ventricles

Question 4

What is the process of the cardiac cycle?

Answer 4

RA receives poorly oxygenated blood from SVC and IVC
RV discharges this to lungs via pulmonary trunk
LA receives well oxygenated blood from the pulmonary veins
LV discharges this to body initially through aorta

Question 5

What can be found on the anterior view of the heart (RHS)?

Answer 5

[PAVAra.C]

pulmonary trunk
aorta
right ventricle
auricle of the right atrium
coronary vessels

Question 6

What can be found on the posterior view of the heart (LHS)?

Answer 6

Pulmonary veins
Auricle of the left atrium
Left ventricle
Left coronary artery
[PAlaVCa]

Question 7

What are the structures found in the atria of the heart? (FoAP.Cs)

Answer 7

fossa ovalis
auricle
pectinate muscle
valve and opening of the coronary sinus

Question 8

What are the structures found in the right ventricle?

Answer 8

pulmonary trunk & pulmonary valve
chordae tendineae
myocardium & papillary muscle
tricuspid valve

Question 9

What are the structures found in the left ventricle?

Answer 9

aorta & valve
chordae tenideae
myocardium & papillary muscle
bicuspid valve

Question 10

What influences the movement of the pericardium?

Answer 10

the great vessels, sternum and diaphragm

Question 11

What are the layers of the pericardium?

Answer 11

serous - internal (parietal and visceral)

fibrous - external

Question 12

Where does the pericardium attach to?

Answer 12

the first part of great vessels

Question 13

Where is the pericardial cavity located?

Answer 13

between the parietal and visceral pericardium and contains small amounts of serous fluid

Question 14

What arteries are responsible for supplying the heart?

Answer 14

the coronary arteries

Question 15

Where do anastomoses occur on the heart?

Answer 15

Between coronary artery branches

Question 16

What is the process by which venous drainage occurs in the heart?

Answer 16

four major cardiac veins drain into the coronary sinus, which drains into right atrium

Question 17

How are nerve impulses conducted in the heart?

Answer 17

the SA node produces excitation signals causing atrial muscle to contract
Impulses spread through atrial wall to AV node via internodal tracts
Continues directly into AV bundle (of His) penetrating the fibrous skeleton
AV bundle divides in muscular inter-ventricular septum into the left and right bundle branches
and continues into the walls of the ventricles to the purkinje fibres

SA / AV / L,R Bundle branches / bundle of His / pkj fibres

Question 18

What is the structure of the fibrous skeleton of the heart?

Answer 18

there is a framework of four fibrous rings of dense connective tissue

Question 19

What is the conducting system of the myocardium regulated by?

Answer 19

the autonomic NS (subconscious)

Question 20

What levels of the conducting system of the heart is the sympathetic innervation from?

Answer 20

T1-5, symp trunk, cardiac plexus

Question 21

How does the pulmonary trunk branch?

Answer 21

into the left and right pulmonary arteries and enters the hilum

Question 22

What are the different pulmonary veins and what is their function?

Answer 22

Two veins from each side - inferior (R&L) and superior (R&L)
to transport oxygenated blood from lungs to left atrium

Question 23

How does the inferior vena cava travel to the heart?

Answer 23

it pierces up through the diaphragm then doesn’t have a long way to travel to get to the right atrium

Question 24

What are the two regions of the right atrium?

Answer 24

Sinus venarum

Pectinate muscle

Question 25

What are the three sources of venous blood flowing into the right atrium?

Answer 25

Superior vena cava Inferior vena cava Coronary sinus

Question 26

Why is the sinus venarum smooth walled?

Answer 26

the smooth walled parts of the heart often lie where the inflow and outflow of blood is occurring so it's really important in these regions to have nice, smooth surfaces for allow the flow of blood

Question 27

What is the function of the trabeculae carneae?

Answer 27

they prevent surface adhesion between the walls of the ventricles they help with the contraction of the ventricles

Question 28

What are the two cusps in both AV valves (and what is the third cusp in the tricuspid / right valve)?

Answer 28

anterior posterior (septal)

Question 29

What are the three leaflets of the SL valves?

Answer 29

Left Right Anterior

Question 30

Where do the left and right leaflets of the SL valves lead to?

Answer 30

the left and right coronary arteries

Question 31

In what orientation is the pericardium attached to the great vessels and to the diaphragm?

Answer 31

great vessels - superiorly | diaphragm - inferiorly

Question 32

What three structures influence the pericardium on movement?

Answer 32

thoracic viscera sternum diaphragm

Question 33

Where is the phrenic nerve in relation to the pericardium?

Answer 33

the phrenic nerve travels over the pericardium

Question 34

What are the functions of the pericardium?

Answer 34

protects cardiac distension | retains the heart in position via its ligaments

Question 35

Why don't the sternopericardial ligaments allow for cardiac expansion of the heart?

Answer 35

bc the heart is so fibrous / rigid

Question 36

What are the two main layers of the pericardium?

Answer 36

Serous pericardium | Fibrous pericardium

Question 37

What does the pericardial cavity contain and what is its function?

Answer 37

small amount of serous fluid | to allow for uninhibited movement

Question 38

What two layers make up the serous pericardium?

Answer 38

``` Parietal layer Visceral layer (or Epicardium) ```

Question 39

What is the function of the fibrous pericardium?

Answer 39

protects the heart anchors it to the surrounding walls prevents it from overfilling with blood

Question 40

What happens where the parietal and visceral layers of the serous pericardium meet?

Answer 40

the reflections form 2 sinuses

Question 41

Where are the transverse and oblique sinuses located?

Answer 41

transverse - between outflow vessels and inflow vessels of the heart oblique - between pulmonary veins

Question 42

What can the transverse sinuses be used for?

Answer 42

in surgery to clamp the outflow of blood from the heart

Question 43

Where are the coronary vessels located?

Answer 43

in the AV and IVT grooves

Question 44

What are the two main coronary arteries that arise from the ascending aorta?

Answer 44

Right and left coronary arteries

Question 45

What are the three branches of the right coronary artery?

Answer 45

(SA.R.PoV) SA node branch Right marginal branch Posterior Ventricular branch

Question 46

What are the four branches of the left coronary artery? (CLAD)

Answer 46

(Cir.LeM.AnIB.Diag'AIB) circumflex branch left marginal branch anterior interventricular branch diagonal branch of anterior interventricular branch

Question 47

What are the two types of anastamosis?

Answer 47

anatomic (true) | functional (potential)

Question 48

What percent of individuals are right and left coronary artery dominant for the PDA? Is coronary circulation varied?

Answer 48

67% - RCA dominant 15% - LCA dominant Variation in the coronary circulation is common

Question 49

What % of individuals have an accessory CA? What % have the SA nodal branch coming off the circumflex?

Answer 49

4% | 40%

Question 50

Where is the SA node located?

Answer 50

close to crista terminalis at junction between SVC and right atrium

Question 51

Where is the AV node located?

Answer 51

interatrial septum close to coronary sinus opening

Question 52

How do the SA and AV node perform a heart beat?

Answer 52

the SA node initiates contraction impulses spread through right atrial wall to left atrium - AV node via internodal tracts AV node continues into AV bundle (of His) divides in the interventricular septum to travel to left and right ventricles conducts the impulse to the left and right Purkinje fibres

Question 53

What are the features of the fibrous skeleton of the heart?

Answer 53

Framework of 4 fibrous rings of dense connective tissue

Question 54

What are the functions of the fibrous skeleton of the heart?

Answer 54

provides attachment for AV and SL valves | forms an electrical insulator between the atria and ventricles

Question 55

What is the innervation of the myocardium?

Answer 55

nerves from the ANS destined for the heart enter the Cardiac Plexus

Question 56

How do the parasympathetic fibres travel?

Answer 56

from the vagus nerve enter the cardiac plexus travel to the SA node

Question 57

How do the sympathetic fibres travel?

Answer 57

from the sympathetic trunk levels T1-5 enter the cardiac plexus travels to the SA node

Question 58

What is the largest vein draining the myocardium?

Answer 58

the coronary sinus

Question 59

What four major cardiac veins drain into the coronary sinus?

Answer 59

Great, middle, small, posterior

Question 60

Where do nerves from the ANS destined for the heart enter from and travel to?

Answer 60

the cardiac plexus | SA node

Question 61

What are the four parts of the aorta?

Answer 61

ascending (middle mediastinum) arch (superior mediastinum) descending thoracic (posterior mediastinum) descending abdominal

Question 62

What are the two main coronary arteries that arise from the ascending aorta?

Answer 62

the right and left coronary arteries

Question 63

What is the left anterior descending artery otherwise known as?

Answer 63

anterior interventricular branch of left coronary artery | anterior descending branch

Question 64

What ligaments attach the fibrous pericardium to the sternum?

Answer 64

the superior and inferior sternopericardial ligaments

Question 65

Where does the superior sternopericardial ligament attach the fibrous pericardium to?

Answer 65

the manubrium

Question 66

Where does the inferior sternopericardial ligament attach the fibrous pericardium to?

Answer 66

the xiphoid process

Question 67

What might happen if there was bleeding into the pericardial cavity?

Answer 67

it could put pressure on the heart | any pressure within the pericardium is going to push on the heart rather than making the pericardium expand

Question 68

What is the difference between the trabeculae carneae and the pectinate muscles?

Answer 68

the pectinate muscles are only found in the atria | TC is only present in the ventricles

Question 69

What is the left marginal artery otherwise known as?

Answer 69

obtuse marginal branch

Question 70

What is the coronary sulcus otherwise known as?

Answer 70

coronary groove AV groove auriculoventricular groove

Question 71

What is the largest coronary artery?

Answer 71

(LADA) | left anterior descending artery

Question 72

How many pulmonary veins are there in total?

Answer 72

4 bc an inferior and superior main vein drains each lung

Question 73

What substance do the pulmonary veins transport and where to?

Answer 73

oxygenated blood from lungs to left atrium

Question 74

Where is parasympathetic innervation of the heart from?

Answer 74

vagus nerve to the SA node

Question 75

What is the function of the fibrous skeleton of the heart?

Answer 75

so that the AV and SL valves can attach | acts as an electrical insulator between the atria and ventricles

Question 76

What side of the heart is the anterior view on?

Answer 76

RHS

Question 77

What view is the left side of the heart on?

Answer 77

the posterior view

Question 78

Where are the right and left coronary arteries located?

Answer 78

coronary arteries in the AV and IVT grooves