Cardiac Circulation and Conduction System

Question 1

What is conduction described like in terms of the heart?

Answer 1

Dromotropy

Question 2

What is excitability described like in terms of the heart?

Answer 2

Bathmotropy

Question 3

What is contractility described like in terms of the heart?

Answer 3

Inotropy

Question 4

What is relaxation described like in terms of the heart?

Answer 4

Lusitropy

Question 5

Where does the endocardium receive oxygen and nutrients from?

Answer 5

Directly from the chambers of the heart

Question 6

What are the only branches of the ascending aorta called?

Answer 6

Coronary arteries

Question 7

Where do the coronary arteries arise from?

Answer 7

Aortic sinuses

Question 8

When do coronary arteries fill?

Answer 8

During diastole

Question 9

What is the first branch of the right coronary artery called?

Answer 9

The SA nodal branch

Question 10

What does the RCA travel in?

Answer 10

The coronary sulcus

Question 11

What artery is the right (acute) marginal branch branch off from?

Answer 11

The Right Coronary Artery

Question 12

What artery usually gives off the posterior descending/interventricular branch/artery?

Answer 12

The right coronary artery

Question 13

What does the Left Coronary Artery divide into?

Answer 13

• Left circumflex artery

- Left Anterior interventricular (aka LAD)

Question 14

What artery is known as the widow maker / artery of sudden death?

Answer 14

Left anterior descending artery

Question 15

What does the LAD supply?

Answer 15

sternocostal surface

Question 16

Where does the LAD anastomose?

Answer 16

The apex

Question 17

What does the LAD anastamose with?

Answer 17

posterior interventricular branch of RCA

Question 18

What does the RCA and its branches supply?

Answer 18

• Walls of RA and RV
• SA and AV nodes
• Posterior part of interventricular septum (proximal portion of atrioventricular bundle of His)
• Small areas of LA and LV

Question 19

What does the LCA and its branches supply?

Answer 19

• Walls of LA and LV

- Most of the interventricular septum including part of AV bundle

Question 20

What percentage of people have a right coronary dominance?

Answer 20

80%

Question 21

What is the term given to individuals who have both coronary arteries supplying the posterior descending artery?

Answer 21

Coronary co-dominance

Question 22

What percentage of MI’s are an occlusion of the circumflex?

Answer 22

15-20%

Question 23

What percentage of MI’s are a result of RCA occlusion

Answer 23

30-40%

Question 24

What percentage of MI’s are a result of LAD occlusion?

Answer 24

40-50%

Question 25

What vessels can be used for CABG?

Answer 25

- Internal thoracic arteries - Radial artery - Saphenous vein

Question 26

What is coronary artery bypass grafting?

Answer 26

It diverts blood around narrowed or clogged parts of the major arteries to improve blood flow and oxygen supply to the heart.

Question 27

What percentage of venous blood from the heart enters via the coronary sinus?

Answer 27

60%

Question 28

What dermatomes can cardiac referred pain affect?

Answer 28

T1-T5

Question 29

What are the components of the conduction system?

Answer 29

- SA - AV - Bundle His - Left bundle branch - Right bundle branch - Purkinje fibres

Question 30

Are the nodes of the heart microscopc or macroscopic?

Answer 30

Microscopic

Question 31

What nerves increase HR and force?

Answer 31

Presynaptic sympathetic fibres which travel in T1-5(6) spinal nerves

Question 32

Where can the cardioacceleratory and cardioinhibitory centres be found?

Answer 32

Medullary reticular formation

Question 33

Where can the deep cardiac plexus be found in relation to the great vessels?

Answer 33

- Inferior to aortic arch | - Adjacent to the bifurication of both the pulmonary trunk and trachea

Question 34

What vein(s) drain into the the RA directly?

Answer 34

Anterior cardiac veins

Question 35

What is the great cardiac vein also known as?

Answer 35

The anterior interventricular branch

Question 36

What vein accompanies the right marginal branch?

Answer 36

The small cardiac vein