CVS

Question 1

the heart is supplied by…

Answer 1

the left and right coronary arteries

Question 2

blood flow to the myocardium occurs…

Answer 2

mainly during diastole

Question 3

the left coronary artery divides into…

Answer 3

the left anterior descending (LAD) and circumflex arteries

Question 4

Compared to other veins, the oxygen saturation in coronary venous blood is very low (often O2 saturation of only 35%). This is because…

Answer 4

oxygen extraction by the heart muscle is very high

Question 5

the right coronary artery supplies…

Answer 5

the inferior surface of the heart

Question 6

what is responsible for synthesising coagulation factors and fibrinogen?

Answer 6

the liver

Question 7

what is the precursor for an enzyme that lyses clots?

Answer 7

plasminogen

Question 8

what constitutes the coagulation cascade?

Answer 8

A series of proteolytic enzymes that circulate in plasma in an inactive form and generate thrombin when activated

Question 9

what cleaves fibrinogen to create fibrin?

Answer 9

thrombin

Question 10

what are released upon cell activation and contain a high concentration of a molecule that acts as an agonist at the platelet P2Y12 receptor?

Answer 10

platelet dense granules

Question 11

Responsible for the apex beat normally palpated in the left 5th intercostal space and midclavicular line…

Answer 11

left ventricle

Question 12

Prevents backflow of blood into the left atrium during ventricular systole

Answer 12

mitral valve

Question 13

Carries oxygenated blood from the lungs to the left side of the heart

Answer 13

pulmonary vein

Question 14

Maintains the systemic diastolic blood pressure by preventing backflow of blood into the heart during diastole

Answer 14

aortic valve

Question 15

Prevents high pressures developing in the jugular veins during ventricular systole

Answer 15

tricuspid valve

Question 16

Carries deoxygenated blood back to the right atrium

Answer 16

inferior vena cava

Question 17

This represents ventricular repolarisation

Answer 17

T wave

Question 18

The normal duration for this is 120 to 200 ms (0.12-0.2 sec)

Answer 18

PR interval

Question 19

Assess the electrical activity within the lateral myocardial territory

Answer 19

Leads 1, aVL, V5 and V6

Question 20

This yields complexes that are normally inverted compared to the anterior and inferior leads

Answer 20

Lead aVR

Question 21

Assess the electrical activity within the inferior myocardial territory

Answer 21

Leads II, III and aVF

Question 22

This represents atrial depolarisation

Answer 22

P wave

Question 23

This represents ventricular depolarization and should be less than 120 ms in duration

Answer 23

QRS complex

Question 24

Occlusion is most likely to result in a fatal heart attack?
A. Left main coronary artery
B. Left circumflex artery
C. Right circumflex artery
D. Right main coronary artery
E. Left anterior descending artery

Answer 24

A. Left main coronary artery
Occlusion of the left main coronary artery - it supplies the largest area of heart muscle via its many branches including the left circumflex and LAD.

Question 25

``` Shortness of breath, severe peripheral oedema and ascites after a heart attack indicates A. left heart failure B. isolated septal hypertrophy C. biventricular failure D. biatrial failure E. right heart failure ```

Answer 25

C. biventricular failure

Question 26

Which sentence best describes the relationships of BP & SVR with the parasympathetic nervous system? A. Parasympathetic nerves decrease peripheral blood vessel diameter thereby decreasing systemic vascular resistance and decreasing blood pressure. B. Parasympathetic nerves increase peripheral blood vessel diameter thereby decreasing systemic vascular resistance and decreasing blood pressure. C. Parasympathetic nerves decrease peripheral blood vessel diameter thereby increasing systemic vascular resistance and increasing blood pressure. D. Parasympathetic nerves do not have a major influence on peripheral blood vessel diameter as blood vessels do not have parasympathetic innervation. E. Parasympathetic nerves increase peripheral blood vessel diameter thereby increasing systemic vascular resistance and increasing blood pressure.

Answer 26

D. Parasympathetic nerves do not have a major influence on peripheral blood vessel diameter as blood vessels do not have parasympathetic innervation.

Question 27

What is the purpose of the Ductus Arteriosus in the foetal cardiovascular system? A. allow blood to bypass the foetal lungs by shunting it from the Pulmonary Artery to the Aorta B. allow blood to bypass the foetal lungs by shunting it from the Right Atrium to Left Atrium. C. allow blood to bypass the foetal systematic circulation by shunting it from the Aorta to the Pulmonary Artery. D. allow blood to bypass the foetal systemic circulation by shunting it from the Left Atrium to the Right Atrium. E. allow blood to bypass the foetal Liver by shunting maternal blood to the Inferior Vena Cava.

Answer 27

A. allow blood to bypass the foetal lungs by shunting it from the Pulmonary Artery to the Aorta

Question 28

Cardiac Output is calculated from… A. heart rate x stroke volume B. mean blood pressure x stroke volume C. heart rate x mean blood pressure D. stroke volume x systemic resistance E. mean blood pressure x systemic resistance

Answer 28

A. heart rate x stroke volume

Question 29

``` Describe the normal pathway of electrical conduction through the heart Where A = Sino Atrial Node (SAN) B = Bundle of his C = Contraction of the atria D = Purkinje fibres E = Atrio Ventricular Node (AVN) F = Contraction of the ventricles A. E, C, A, D, B, F B. A, C, E, B, D, F C. A, C, E, D, B, F D. A, E, C, B, D, F E. E, C, A, B, D, F ```

Answer 29

B. A, C, E, B, D, F

Question 30

Consider the pressure changes within the heart and decide which pressure is most affected in the following situation: Increase in this indicates mitral valve stenosis A. Left atrial end-diastolic pressure B. Left atrial end-systolic pressure C. Left ventricular end-diastolic pressure D. Left ventricular end-systolic pressure E. Mean aortic pressure

Answer 30

B. Left atrial end-systolic pressure Mitral stenosis causes an increased resistance to blood flow across the valve therefore a higher pressure is required to force blood from atrium to ventricle i.e. a higher left atrial end systolic pressure.

Question 31

Which sentence best describes the relationships of SVR & BP with the sympathetic nervous system? A. Sympathetic nerves decrease peripheral blood vessel diameter thereby decreasing systemic vascular resistance and decreasing blood pressure. B. Sympathetic nerves increase peripheral blood vessel diameter thereby decreasing systemic vascular resistance and decreasing blood pressure. C. Sympathetic nerves decrease peripheral blood vessel diameter thereby increasing systemic vascular resistance and increasing blood pressure. D. Sympathetic nerves increase peripheral blood vessel diameter thereby increasing systemic vascular resistance and increasing blood pressure. E. Sympathetic nerves do not influence peripheral blood vessel diameter and have no effect on systemic vascular resistance and blood pressure.

Answer 31

C. Sympathetic nerves decrease peripheral blood vessel diameter thereby increasing systemic vascular resistance and increasing blood pressure.

Question 32

Consider the pressure changes within the heart and decide which pressure is most affected in the following situation: Increase in this signifies left heart failure A. Left atrial end-systolic pressure B. Left ventricular end-diastolic pressure C. Mean aortic pressure D. Left atrial end-diastolic pressure E. Left ventricular end-systolic pressure

Answer 32

B. Left ventricular end-diastolic pressure In heart failure there is reduced contractility therefore there will be a reduction in stroke volume so end diastolic volume and end diastolic pressure will be increased.

Question 33

``` Pulmonary oedema in the presence of a normal central venous pressure is a sign of A. right heart failure B. respiratory failure C. left heart failure D. biventricular failure E. biatrial failure ```

Answer 33

C. left heart failure A raised central venous pressure is a reflection of right sided heart failure. Respiratory failure can lead to right heart failure. Left sided heart failure causes and increase in pulmonary pressure leading to pulmonary oedema.

Question 34

``` If the end diastolic volume (EDV) in the average healthy person’s left ventricle is 120mls, what would you expect the end systolic volume (ESV) to be? A. 50mls B. 100mls C. 70mls D. 0mls E. 10mls ```

Answer 34

A. 50mls EDV of 120 mls. Stroke volume of 70 mls in the average person Leaving an ESV of 50 mls

Question 35

``` Which artery most frequently supplies the Atrio-Ventricular Node? A. Left anterior descending artery B. Left circumflex artery C. Right coronary artery D. Posterior descending artery E. Left coronary artery ```

Answer 35

C. Right coronary artery The RCA supplies the area above including both SA & AV nodes. The LAD supplies most of the area below the AV conducting system, the His-Purkinje system.

Question 36

``` Which nerve innervates the pericardium? A. Vagus nerve B. Medial Pectoral nerve C. Internal Thoracic nerve D. Phrenic nerve E. T2-T4 intercostal nerves ```

Answer 36

D. Phrenic nerve

Question 37

``` Severe pulmonary hypertension is a cause of A. biventricular failure B. isolated septal hypertrophy C. left heart failure D. biatrial failure E. right heart failure ```

Answer 37

E. right heart failure Severe pulmonary hypertension means the right ventricle has to work harder to pump blood through the pulmonary artery. Ultimately the right ventricle is unable to generate sufficient pressure and therefore starts to fail.

Question 38

Which of these following statements is correct? A. For part of the cardiac cycle, both atrial and ventricular diastole occur together B. Ventricular volume increases during ventricular systole C. Atrial contraction occurs before the P-wave on ECG D. Atrial systole corresponds to closure of the tricuspid valve E. Ventricular systole corresponds to closure of the pulmonary valve

Answer 38

A. For part of the cardiac cycle, both atrial and ventricular diastole occur together Atrial systole opens the tricuspid valve P wave precedes atrial contraction Ventricular systole opens the pulmonary valve Ventricular volume decreases during systole Both atria and ventricles are in diastole during the isovolumetric ventricular relaxation phase of the cardiac cycle.