Cardiovascular system

Question 1

What happens in the diastolic phase?

Answer 1

relaxation of myocardium

Question 2

What happens in the systolic phase?

Answer 2

Contraction of myocardium

Question 3

What is tachycardia?

Answer 3

resting heart rate above 100bpm

Question 4

what is bradycardia?

Answer 4

heart rate below 60bpm

Question 5

what is premature atrial contraction?

Answer 5

occasional shortened intervals between contractions

Question 6

Cardiac output

Answer 6

The amount of blood the heart pumps through the circulatory system in a minute.
CO = Heart rate x Stroke vol

Question 7

Stroke volume

Answer 7

volume of blood pumped by a ventricle per beat
SV = End diastolic vol (EDV) - End systolic vol (ESC)

Question 8

ejection fraction

Answer 8

% of EDV pumped by ventricle

Question 9

what happens during ventricular filling?

Answer 9

ventricular diastole (relax)
atrial systole (contract)

Question 10

isovolumetric contraction

Answer 10

ventricles contract (systole)
AV valve closed

Question 11

ventricular ejection

Answer 11

ventricles contract (systole)

Question 12

isovolumetric relaxation

Answer 12

ventricles and atria relax (diastole)

Question 13

what does the impulse conductor do?

Answer 13

ensures atria and ventricles contract separately

Question 14

What is preload?

Answer 14

tension/stetching before muscle works
EDV

Question 15

what is afterload?

Answer 15

pressure that preloaded muscle has to work against

Question 16

what effect does increase in preload have on cardiac output?

Answer 16

increases CO

Question 17

what happens to cardiac output when afterload is increased?

Answer 17

CO decreases

Question 18

3 steps of the renin-angiotensin-aldosterone system?

Answer 18

1) renin secreted by kidneys when BP is reduced
2) converts angiotensinogen to angiotensin I
3) ACE converts angiotensin I to II

Question 19

Actions of angiotensin II?

Answer 19

vasoconstriction
causes release of aldosterone
increase blood volume and pressure

Question 20

function of ACE inhibitors?

Answer 20

inhibit angiotensin formation
decrease aldosterone

Question 21

what happens at the SA node?

Answer 21

generates spontaneous action potentials

Question 22

what happens at AV node?

Answer 22

Action potentials conducted slowly
ensures that ventricles contract after atria

Question 23

Function of purkinje fibres?

Answer 23

conduct action potentials to ventricle muscles (myocardium)

Question 24

heart attack

Answer 24

deprivation of supply of blood to tissue

Question 25

cardiac arrest

Answer 25

disruption to control of contractions

Question 26

heart failure

Answer 26

inability to distribute blood around body