Lectures 14 and 15

Question 1

when AV valves are open, most blood returning to atria pass right through to the ______ (60-90% of blood)

Answer 1

ventricles (this is a function of the atria)

Question 2

when atria do ______, they push more blood into ventricles (10-40%)

Answer 2

contract (this is a function of atria)

Question 3

atria function to enhance the amount of ______ in ventricles, which enhances ventricular pumping

Answer 3

blood (this is a function of atria)

Question 4

yes or no? the heart can function without atrial contraction

Answer 4

yes (this is a function of atria)

Question 5

what is the function of the ventricles?

Answer 5

pump blood through pulmonary circulation (right) and systemic circulation (left)

Question 6

valves ____ and _____ passively

Answer 6

open; close (this is a function of valves)

Question 7

forward pressure gradient ____ valves

Answer 7

open (this is a function of valves)

Question 8

backward pressure gradient _____ valves

Answer 8

closes (this is a function of valves)

Question 9

papillary muscle of AV valves prevent _____ from protruding into as ventricles contract

Answer 9

cusps (this is a function of valves)

Question 10

damage to chordae tendinae or papillary muscle results in _______ flow of blood as ventricles contract and could be lethal

Answer 10

backward (this is a function of valves)

Question 11

yes or no? semilunar valves have chordae tendinae or papillary muscle

Answer 11

no

Question 12

the cardiac cycle refers to the sequence of events (electrical and mechanical) occurring in the heart during a ______

Answer 12

single beat

Question 13

1. atrial contraction
2. isovolumetric contraction
3. ejection
4. isovolumetric contraction
5. ventricular filling

Answer 13

phases of the cardiac cycle

Question 14

AV valve is open; atrium pumps blood into ventricle

Answer 14

atrial contraction

Question 15

ventricle begins to contract-once pressure in ventricle exceed that of atrium, the AV valve will close

Answer 15

period of isovolumetric contraction

Question 16

the period of contraction while the AV valve and semilunar valve are closed

Answer 16

isovolumetic contraction phase

Question 17

once the pressure in the ventricle exceeds that of the aorta (arterial pressure) then the semilunar valve will open (leading to the ejection phase)

Answer 17

isovolumetric contraction

Question 18

as ventricular pressure rises above arterial pressure, semilunar valve opens and blood is ejected out of ventricles

Answer 18

period of ejection

Question 19

ventricle begins to relax; pressure begins to drop within ventricle

Answer 19

period of isovolumetric relaxation

Question 20

as pressure drops below arterial pressure, semilunar valve closes

Answer 20

period of isovolumetric relaxation

Question 21

period of relaxation while both valves (AV and semilunar valves) are closed

Answer 21

isovolumetric relaxation phase

Question 22

ventricle continues to relax and eventually the pressure drops below that of atrium and therefore the AV valve opens (leading to the ventricular filling phase)

Answer 22

isovolumetric relaxation phase

Question 23

passive filling of ventricle

Answer 23

ventricular filling

Question 24

contraction phase of cardiac cycle

Answer 24

systole

Question 25

relaxation phase of cardiac cycle

Answer 25

diastole

Question 26

the pressure in the systemic arteries (aorta) while the left ventricle is contraction and ejecting blood

Answer 26

systolic blood pressure

Question 27

the pressure in the systemic arteries (aorta) while the left ventricle is relaxing and not ejecting blood

Answer 27

diastolic blood pressure

Question 28

the volume of blood in the ventricle at the end of diastole; the amount of blood in the ventricle before it contracts

Answer 28

end diastolic volume (EDV)

Question 29

venous return is an important determinant of ____

Answer 29

end diastolic volume (EDV)

Question 30

the volume of blood in the ventricle at the end of systole

Answer 30

end systolic volume (ESV)

Question 31

the volume of blood pumped out of the left ventricle per contraction; determined by preload, afterload, and contractility

Answer 31

stroke volume (SV)

Question 32

the fraction of EDV that was pumped out of the left ventricle per contraction

Answer 32

ejection fraction | SV/EDV X100= EF

Question 33

the amount of blood pumped out of the left ventricle per minute

Answer 33

``` cardiac output (CO, Q) CO= HR X SV ```

Question 34

the amount of blood returned to the heart

Answer 34

venous return

Question 35

the pressure stretching the chamber of the heart before it contracts

Answer 35

preload

Question 36

_____ is determined primarily by EDV

Answer 36

preload

Question 37

as the muscle stretches, the stretching induces length-dependent activation of the contractile apparatus leading to greater strength of contraction. in other words, ______ is the stretched state of the ventricle before it contracts; the greater the stretch, the greater the ______....so when it contracts it will contract with greater force

Answer 37

preload; preload

Question 38

the pressure that the chamber of the heart has to overcome in order to eject blood

Answer 38

afterload

Question 39

_______ pressure is an important determinant of the afterload of the left ventricle

Answer 39

aortic

Question 40

______ pressure is an important determinant of the afterload of the right ventricle

Answer 40

pulmonary

Question 41

as ______ pressure increases, the ______ of the left ventricle increases

Answer 41

aortic; afterload

Question 42

the intrinsic ability of cardiac muscle to produce tension, independent of fiber (sarcomere) length

Answer 42

contractility (inotropy)

Question 43

a change in the _____ of contraction at a constant end-diastolic fiber length reflects a change in contractility

Answer 43

force

Question 44

intracellular ______ concentration is an important determinant of contractility

Answer 44

calcium

Question 45

anything that stimulates an increase in intracellular calcium concentration in cardiomyocytes will ______ contractility

Answer 45

increase

Question 46

an increase in preload or an increase in contractility will each ________ the strength of contraction

Answer 46

increase

Question 47

affecting heart rate

Answer 47

chronotropic effect

Question 48

affecting contractility

Answer 48

inotropic effect

Question 49

the work that the heart is able to perform beyond that is required of it under basal/resting conditions (300-400%)

Answer 49

cardiac reserve

Question 50

an indirect index of myocardial oxygen consumption (how hard the ventricle is working)

Answer 50

pressure-rate product or double product HR X SPB (or MAP)

Question 51

what kind of sound does the heart make?

Answer 51

lub-dub (S1 and S2)

Question 52

S1 or S2? closing of AV valves

Answer 52

S1

Question 53

S1 or S2? closing of semilunar valves

Answer 53

S2

Question 54

presence of S3 and/or S4 may be indicative of an ________

Answer 54

abnormality

Question 55

S3 or S4? vibrations during rapid phase of ventricular filling

Answer 55

S3

Question 56

_____ is thought to be caused by the oscillation of blood back and forth between the walls of the ventricles initiated by inrushing blood from the atria (increased volume of blood within the ventricle; may be associated with ventricular dilation)

Answer 56

S3

Question 57

S3 or S4? may be heard during atrial contraction

Answer 57

S4

Question 58

S3 or S4? may be heard when atrial pressure is high or ventricle is stiff (ex: ____ may be heard if there is ventricular hypertrophy; hypertrophy causes stiffening of the ventricle)

Answer 58

S4

Question 59

T or F? the mitral valve opens due to contraction, and corresponding pressure rise, of the atrium?

Answer 59

false

Question 60

how would aortic stenosis affect afterload?

Answer 60

increase it

Question 61

what effect does increased afterload have on SV?

Answer 61

decrease it

Question 62

how will an increase in afterload affect ESV?

Answer 62

increase it

Question 63

Yes or No? in order to increase contractility, does there have to be an increase in EDV?

Answer 63

no