CVS Flashcards
the heart is supplied by…
the left and right coronary arteries
blood flow to the myocardium occurs…
mainly during diastole
the left coronary artery divides into…
the left anterior descending (LAD) and circumflex arteries
Compared to other veins, the oxygen saturation in coronary venous blood is very low (often O2 saturation of only 35%). This is because…
oxygen extraction by the heart muscle is very high
the right coronary artery supplies…
the inferior surface of the heart
what is responsible for synthesising coagulation factors and fibrinogen?
the liver
what is the precursor for an enzyme that lyses clots?
plasminogen
what constitutes the coagulation cascade?
A series of proteolytic enzymes that circulate in plasma in an inactive form and generate thrombin when activated
what cleaves fibrinogen to create fibrin?
thrombin
what are released upon cell activation and contain a high concentration of a molecule that acts as an agonist at the platelet P2Y12 receptor?
platelet dense granules
Responsible for the apex beat normally palpated in the left 5th intercostal space and midclavicular line…
left ventricle
Prevents backflow of blood into the left atrium during ventricular systole
mitral valve
Carries oxygenated blood from the lungs to the left side of the heart
pulmonary vein
Maintains the systemic diastolic blood pressure by preventing backflow of blood into the heart during diastole
aortic valve
Prevents high pressures developing in the jugular veins during ventricular systole
tricuspid valve
Carries deoxygenated blood back to the right atrium
inferior vena cava
This represents ventricular repolarisation
T wave
The normal duration for this is 120 to 200 ms (0.12-0.2 sec)
PR interval
Assess the electrical activity within the lateral myocardial territory
Leads 1, aVL, V5 and V6
This yields complexes that are normally inverted compared to the anterior and inferior leads
Lead aVR
Assess the electrical activity within the inferior myocardial territory
Leads II, III and aVF
This represents atrial depolarisation
P wave
This represents ventricular depolarization and should be less than 120 ms in duration
QRS complex
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
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.
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
C. biventricular failure
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.
D. Parasympathetic nerves do not have a major influence on peripheral blood vessel diameter as blood vessels do not have parasympathetic innervation.
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.
A. allow blood to bypass the foetal lungs by shunting it from the Pulmonary Artery to the Aorta
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
A. heart rate x stroke volume
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
B. A, C, E, B, D, F
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
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.
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.
C. Sympathetic nerves decrease peripheral blood vessel diameter thereby increasing systemic vascular resistance and increasing blood pressure.
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
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.
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
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.
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
A. 50mls
EDV of 120 mls.
Stroke volume of 70 mls in the average person
Leaving an ESV of 50 mls
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
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.
Which nerve innervates the pericardium? A. Vagus nerve B. Medial Pectoral nerve C. Internal Thoracic nerve D. Phrenic nerve E. T2-T4 intercostal nerves
D. Phrenic nerve
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
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.
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
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.
