A&p Chapter 20: The Heart

Front 1

What is The Cardiac Cycle?

Back 1

The period between the start of 1 heartbeat and the beginning of the next

Front 2

The Cardiac Cycle includes both contraction and relaxation, true or false?

Back 2

true

Front 3

What are the 2 Phases of the Cardiac Cycle?

Back 3

systole (contraction) and diastole (relaxation)

Front 4

During systole, does blood pressure rise or fall?

Back 4

rises

Front 5

Blood pressure does what during diastole?

Back 5

falls

Front 6

What are the 4 Phases of the Cardiac Cycle?

Back 6

1. Atrial systole
2. Atrial diastole
3. Ventricular systole
4. Ventricular diastole

Front 7

When heart rate increases, what happens with all the phases of cardiac cycle?

Back 7

they shorten, especially diastole

Front 8

At 75 beats per minute, the cardiac system lasts how long?

Back 8

about 800 msecs

Front 9

How many steps are in the Cardiac Cycle?

Back 9

8

Front 10

Lack of adequate blood flow to peripheral tissues and organs due to ventricular damage is what?

Back 10

heart failure

Front 11

What are the 4 Heart Sounds?

Back 11

S1, S2, S3, and S4

Front 12

Describe S1:

Back 12

they are loud sounds,
produced by AV valves

Front 13

Describe the heart sound S2:

Back 13

makes loud sounds, produced by semilunar valves

Front 14

S3 and S4 are both what kind of sounds, soft or loud?

Back 14

soft

Front 15

What makes the sounds of S3 and S4?

Back 15

blood flow into ventricles and atrial contraction

Front 16

What is Heart Murmur?

Back 16

sounds produced by regurgitation through valves

Front 17

What is Cardiodynamics?

Back 17

the movement and force generated by cardiac contractions

Front 18

Stroke Volume is what?

Back 18

amount of blood pumped out with every heart beat

Front 19

Cardiac output is adjusted by changes in what?

Back 19

heart rate or stroke volume

Front 20

What is adjusted by the autonomic nervous system or hormones?

Back 20

heart rate

Front 21

Stroke volume is adjusted by:

Back 21

changing EDV (end-diastolic volume) or ESV (end-systolic volume)

Front 22

Cardiac plexuses innervate what?

Back 22

heart

Front 23

The Vagus nerves (X) carries what to small ganglia in cardiac plexus?

Back 23

parasympathetic preganglionic fibers

Front 24

What are the 2 Cardiac centers of medulla oblongata?

Back 24

cardioacceleratory and cardioinhibitory centers

Front 25

What does the cardioacceleratory center do?

Back 25

controls sympathetic neurons (increase heart rate)

Front 26

What does the cardioinhibitory center do?

Back 26

controls parasympathetic neurons (slow heart rate)

Front 27

In Cardiac reflexes, cardiac centers monitor what?

Back 27

baroreceptors (blood pressure) and chemoreceptors (arterial oxygen and carbon dioxide levels)

Front 28

What adjusts cardiac activity?

Back 28

Cardiac centers

Front 29

ACh (parasympathetic stimulation) speeds or slows the heart?

Back 29

slows

Front 30

NE (sympathetic stimulation) does what to the heart?

Back 30

speeds it up

Front 31

Rate of spontaneous depolarization in Autonomic Pacemaker Regulation depends on what 2 things?

Back 31

1. resting membrane potential
2. and rate of depolarization

Front 32

Membrane potential of pacemaker cells are higher or lower than other cardiac cells?

Back 32

lower

Front 33

Atrial Reflex is also called?

Back 33

Bainbridge reflex

Front 34

Atrial Reflex adjusts what in response to venous return?

Back 34

heart rate

Front 35

Stretch receptors in right atrium trigger what through increased sympathetic activity?

Back 35

increase in heart rate

Front 36

Increased heart rate (by sympathetic stimulation of SA node) is cause by what hormones?

Back 36

epinephrine (E), norepinephrine (NE), and thyroid hormone

Front 37

What are 2 Factors that affect EDV (end-diastolic volume)?

Back 37

Filling time and Venous Return

Front 38

What is Filling time?

Back 38

duration of ventricular diastole

Front 39

What is Venous Return?

Back 39

rate of blood flow during ventricular diastole

Front 40

What is Preload?

Back 40

the degree of ventricular stretching during ventricular diastole

Front 41

Preload is directly proportional to what?

Back 41

EDV

Front 42

Preload affects what?

Back 42

the ability of muscle cells to produce tension

Front 43

When are EDV and stroke volume low, and myocardium stretches less?

Back 43

at rest

Front 44

With exercise, EDV, myocardium, and stroke volume do what?

Back 44

EDV increases,
myocardium stretches more,
and stroke volume increases

Front 45

The Frank–Starling Principle states what?

Back 45

As EDV increases, stroke volume increases

Front 46

Ventricular expansion is limited by:

Back 46

myocardial connective tissue,
the fibrous skeleton,
and the pericardial sac

Front 47

What is End-Systolic Volume (ESV)?

Back 47

amount of blood remaining in the ventricle at the end of ventricular systole (heart contraction)

Front 48

There are 3 Factors that Affect ESV, what are they?

Back 48

Preload, Contractility, and Afterload

Front 49

What is Contractility?

Back 49

force produced during contraction

Front 50

What is Afterload?

Back 50

the tension the ventricle produces to open the semilunar valve and eject blood

Front 51

What affects contractility?

Back 51

autonomic activity and hormones

Front 52

How does Autonomic Activity affect contractility through sympathetic stimulation?

Back 52

– NE released by postganglionic fibers of cardiac nerves
– epinephrine and NE released by adrenal medullae
– causes ventricles to contract with more force
– increases ejection fraction and decreases ESV

Front 53

How does Autonomic Activity affect contractility through parasympathetic stimulation?

Back 53

– acetylcholine released by vagus nerves
– reduces force of cardiac contractions

Front 54

What mimics hormone actions when affecting contractility?

Back 54

Pharmaceutical drugs

Front 55

How do Pharmaceutical drugs mimic hormone actions?

Back 55

They stimulate or block beta receptors, and
affect calcium ions (e.g., calcium channel blockers)

Front 56

What is increased by any factor that restricts arterial blood flow?

Back 56

Afterload

Front 57

As afterload increases, what decreases?

Back 57

stroke volume

Front 58

What are 3 Heart Rate Control Factors?

Back 58

1. Autonomic nervous system:
sympathetic and parasympathetic
2. Circulating hormones
3. Venous return and stretch receptors

Front 59

The Stroke Volume Control Factors are?

Back 59

EDV & ESV

Front 60

The difference between resting and maximal cardiac output is called?

Back 60

Cardiac Reserve

Front 61

Stroke Volume is equal to what percent of end-diastolic volume?

Back 61

60%

Front 62

What is the relationship of stroke volume with EDV and ESV?

Back 62

SV = EDV — ESV

Front 63

What is Ejection fraction?

Back 63

the percentage of EDV represented by SV

Front 64

What is Cardiac output (CO)?

Back 64

volume pumped by each ventricle in 1 minute