Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cardiovascular and Pulmonary > Cardiovascular Systems Physiology and Pathophysiology > Flashcards

Cardiovascular Systems Physiology and Pathophysiology Flashcards

1
Q

Describe the vasculature that blood passes through as it leaves the heart

A

Heart (oxygenated blood) —> arteries —> arterioles —> capillary beds (gas exchange) —> venules (deoxygenated blood) —> veins —> SVC and IVC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the component of the microcirculation of blood?

A

Arterioles, capillaries, and venules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The vena cava empty mixed venous blood (i.e.

deoxygenated blood from the superior and inferior circulatory beds) into the

A

Right atrium of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

At any given moment in time, most of our blood is in the

A

Venous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Sequential blood flow through the central cardiovascular system during one complete cardiac
cycle is as follows:

A

Right atrium —> tricuspid valve —> right ventricle —> pulmonic semilunar valve —> pulmonary arteries (Deoxy) —> lungs —> pulmonary veins (Oxy) —> left atrium —> bicuspid valve —> left ventricle —> aortic semilunar valve —> aortic arch —> aorta —> arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The heart functions as two pumps in series which allow for which two types of circulations?

A
  1. ) Pulmonary circuolation (Exchange of CO2 for O2)

2. ) Systemic circulation (exchange of O2 for CO2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In general, two phases of the cardiac pump occur and are defined by the properties of the ventricles. They are:

A
  1. ) Diastole: Ventriclular relaxation (low intraventricular pressure)
  2. ) Systole: Ventricular contraction (high intraventricular pressure)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Cardiac muscle is known as

A

Myocardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Comprise the major portion of the ventricles by volume, however occupy only 25-30% by number

A

Cardiomyocytes (or just myocytes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The heart beats on average around 100,000 beats per day to circulate around 6 tons of blood per day. This is a metabolically expensive process that uses approximately

A

6 kg of ATP daily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The substrate for all of this comes predominantly from

A
  1. ) Glucose (glycolysis)

2. ) Free fatty acids (FFA β-oxidation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Glucose and free fatty acids feed into oxidative phosphorylation for generation of

A

ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In a healthy adult, approximately 60% of ATP is derived from

A

FFA β-oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Under conditions of stress (e.g., heart failure or ischemia), a shift occurs resulting in proportionally more ATP being generated from

A

Glucose oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

This metabolic shift is important when you consider that glucose oxidation yields around

A

13% ATP per O2 molecule consumed than FFA β-oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The use of FFA for energy in the heart is energetically wasteful because FFA stimulate the synthesis of

A

Mitochondrial uncoupling proteins

-releases heat instead of ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Collectively, the stressinduced shift from the β-oxidation of FFA to the oxidation of glucose results in the production of approximately

A

40% more ATP per O2 molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which has a thinner myocardium, atria or ventricles?

A

Atria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the cells of the myocardium called?

A

Myocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Contraction of the myocyte operates via the sliding filament model that depends on

A

Ca2+ and ATP-dependent cross bridge cycling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The contractile element of the myocyte is referred to as the

A

Sarcomere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Intercalated disks form the end borders between myocyte fibers; and the fibers are separated laterally by the

A

Plasma membrane-like Sarcolemma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Cardiac muscle resembles a syncytium in that each fiber contains multiple nuclei; i.e. cardiac muscle fibers operate as a

A

Functional syncytium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Cardiac muscle cells and fibers are joined by

A

Gap junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Enable a high degree of electrical conductivity as well

as the free diffusion of very small molecules such as ions and some second messengers between cells

A

Gap junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Cardiac myocytes utilize oxidative phosphorylation for the production of ATP; thus, the cells are rich in

A

Mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Intracellular Ca2+ sinks that cab bolster sarcoplasmic Ca2+ concentrations

A

Mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

An isoform of creatine kinase that is referred to as cardiac-specific CK

A

Creatine kinase MB (CK-MB)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the clinical importance of CK-MB?

A

CK-MB is dumped following a myocardial infarcation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How many hours from a myocardial infarction do we see:

  1. ) Rise of CK-MB
  2. ) Peak of CK-MB
  3. ) Return to normal CK-MB
A
  1. ) 3-8 hours
  2. ) 24 hours
  3. ) 48-72 hours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Since there are other CK isoforms, the ratio of CK-MB: total CK is measured. A reliable marker for myocardial injury is CK-MB : Total CK ratio of

A

> 2.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Cardiac muscle contains a T-tubule network as well as an abundant representation of

A

Sarcoplasmic reticulum (SR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Cardiac muscle fibers are well vascularized, such that we have what type of correlation between capillaries and mucle fibers?

A

One capillary per muscle fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Like skeletal muscle, cardiac sarcomeres contain Z discs (Z lines) that anchor

A

Actin filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Like creatine kinases, there are specific cardiac

troponins. These are

A
  1. ) Cardiac troponin 1 (cTn1)

2. ) Cardiac troponin T (cTnT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

In the event of a myocardial infarction, cTn1 and cTnT will both rise. When will we see their

  1. ) Rise
  2. ) Peak
  3. ) Return to normal
A
  1. ) 3-4 hours post infarction
  2. ) 18-36 hours post infarction
  3. ) 10-14 days post infarction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the current gold standard for diagnosis of a myocardial injury?

A

Measurement of the cardiac troponins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Cardiac muscle fibers are strongest at the

A

Onset of contraction (from approximately L0)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Unlike skeletal muscle, we see a greater contractile force when cardiac muscle is

A

Stretched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

This is because unlike skeletal muscle, a very slight stretch from L0 is one signal to the cardiomyocyte to

A

Release intracellular Ca2+ from SR and mitochondria

41
Q

With increase intracellular Ca2+ comes

A

Increased contractile force

42
Q

When compared to other muscle types, cardiac muscle can develop much more tension from

A

Stretch

43
Q

Represents the phase following the ejection of blood from the left ventricle (LV)

A

Beinning of diastole

44
Q

Diastole is considered the relaxed (resting) stage; hence the LV fibers have essentially no

A

Load

45
Q

During diastole the

  1. ) Aortic valve is
  2. ) Mirtal valve is
A
  1. ) Closed

2. ) Open

46
Q

During early diastole, the mitral valve opens in response to an

A

Increasing LA pressure (from filling) and low LV pressure

-When mitral valve opens, LV begins to fill

47
Q

The atria contract in response to SA nodal firing;

this represents the later stage of

A

Ventricular diastole

48
Q

Only about 20% of ventricular filling is due to

A

Atrial systole

49
Q

Filling causes preload on the LV muscle fibers. In other words, preload is caused by blood induced filling that causes

A

Stretch from L0

50
Q

What is laplaces law for the left ventricle?

A

T = P x r

Wall tension = Pressure x radius

51
Q

Therefore, greater chamber wall tensions are experienced with greater filling, and increased wall tension upregulates

A

Oxygen demand

52
Q

As the LV muscle fibers are stretched to the optimal length, intracellular Ca2+ is increased and systole begins; this early systolic phase is specifically referred to as

A

Isovolumetric contraction

53
Q

The optimal myosin cross-bridge/actin overlap is referred to as the

A

Optimal length

54
Q

Contraction of cardiomyocytes depends upon Na+ stimulated AP that in turn activates

A

Voltage-dependent Ca2+ channels

55
Q

What happens during isovolumetric contraction?

A

Mitral and aortic valves are closed and LV pressure (LVP) soars

56
Q

As isovolumetric contraction proceeds, the resistance of aortic blood pressure against LVP is added, and this opposing aortic pressure is known as

A

Afterload

57
Q

What must happen in order for the LV to empty efficiently?

A

Preload must be greater than afterload

58
Q

As the force of isovolumetric contraction exceeds afterload, the aortic semilunar valve is pushed open, the LV ejects blood into the aorta, and

A

Systolic contraction of the LV terminates

59
Q

When arterial blood pressure is increased, the heart has to work even harder to eject blood from the LV. This is the case often seen with

A

Hypertension

60
Q

In cardiac muscle, how do we represent

  1. ) Stress
  2. ) Length
A
  1. ) Pressure

2. ) Volume

61
Q

The relationship between volume and pressure seen in the heart are referred to as the

A

Frank-Starling Laws

62
Q

Explains what happens to the stress (pressure) in a cardiac cycle?

A

Minimum stress exists at L0. Then as the chamber fills (increased LVV during diastole) a slight stretch from L0 is initiated and from the onset of isovolumetric contraction, we see an exponential increase in the rise of stress (pressure). Then, as contraction proceeds (chamber emptying, systole) and blood is ejected, the rate of rise of pressure (stress) slows, peaks, and begins a rapid exponential decline and returns to near zero at the end of systole

63
Q

The pressure-volume plot shows these relationships during one cardiac cycle and reads sequentially from

A

Left to right, then bottom to top, then right to left, then top to bottom

64
Q

Phase 1 of the pressure-volume plot represents

A

Diastolic filling and generation of preload

65
Q

The difference between the beginning of isovolumetric relaxation and end diastolic volume (EDV) represents the

A

Stroke volume (SV)

66
Q

Phase 2 of the pressure-volume plot represents

A

The isovolumetric contraction stage of systole

67
Q

Phase 3 of the pressure-volume plot represents

A

Systolic ejection

68
Q

Phase 4 of the pressure-volume plot represents

A

Isovolumetric relaxation

69
Q

Represent the maximal ventricular pressure developed at a given inotropic state

A

The end systolic pressure-volume (ESPVR) plots

70
Q

What are the effects of an increased end diastolic volume (EDV)?

A

Increased preload, increased systolic intraventricular pressure (IVP), and slightly increased end systolic volume (ESV)

71
Q

Will increase both systolic IVP and ESV and result in a greater ESV than increased preload

A

Increased afterload

72
Q

How does positive inotropy change the pressure-volume relationship?

A

Reduced ESV (from greater systolic ejection) and increased stroke volume

73
Q

What is phase 1 of a velocity of fiber shortening vs LVV?

A

Muscle fiber velocity is 0, ventricular myocardium is relaxing

74
Q

What is phase 2 of a velocity of fiber shortening vs LVV?

A

Isovolumetric contraction that terminates upon aortic valce opening

75
Q

Myocyte tension rises dramatically during

A

Isovolumetric contraction

76
Q

Myocyte tension rises dramatically during isovolumetric contraction. This provides the generation of force that is required to

A

Overcome afterload and push open aortic valve

77
Q

The rapid decline in muscle fiber shortening during phase 3 represents

A

Systole

78
Q

The velocity of muscle fibers shortening precipitously declines during

A

Systole

79
Q

Increased afterload is translated as an opposing force that results in a

A

Robust decrease in contractile velocity and increase in ESV

80
Q

Abnormally increased preload causes a

A

Slight decrease in contractile velocity and a concomitant increase in ESV

81
Q

Why does an abnormally increased preload cause a slight decrease in contractile velocity?

A

Because the fibers are stretched beyond optimal length for myosin-actin overlap

82
Q

Naturally occurring and pharmacologic factors that can alter the force of cardiac muscle contractility

A

Inotropic compounds

83
Q

What 4 things do positive inotropins increase?

A
  1. ) Ventricular contractile force
  2. ) EDV
  3. ) Contractile velocity
  4. ) May or may not alter time between excitation episodes
84
Q

Thus, a positive inotropin such as adrenergics or digitalis may increase

-as long as HR does not increase such that the time required for ventricular filling is compromised

A

Cardiac output

85
Q

The goal of positive inotropic compounds is to increase

A

Cardiac pumping efficiency

86
Q

Contraction of cardiac muscle is dependent upon APs induced by

A

Na+ influx

87
Q

Contraction of cardiac muscle is dependent upon APs induced by Na+ influx, and contraction results from (and depends upon)

A

Increased sacoplasmic Ca2+

88
Q

Prolongs the duration of contraction, thus lengthening the QT interval within the electrocardiogram (ECG)

A

Hypocalcemia

89
Q

Reduces the duration of contraction, and thereby shortens the QT interval

A

Hypercalcemia

90
Q

The effects of abnormally high or low calcium on QT involve allosteric modulation by calcium on the voltage-gated Na+ channels which control

A

Ventricular myocyte depolarization

91
Q

Abnormally low extracellular calcium (hypocalcemia) tends to cause a rapid

A

Activation-inactivation of these Na+ channels

92
Q

A cardiac glycoside; this drug that inhibits the Na+/K+ ATPase within the cardiomyocytes, this results in increased intracellular Na+

A

Digoxin

93
Q

Elevated intracellular Na+ impedes the

A

Na+/Ca2+ exchanger (NCX)

94
Q

Trades Na+ import for Ca2+ export from cardiomycetes

A

NCX

95
Q

What are the effects of impeding the NCX?

A

Intracellular Ca2+ increaes, thus enhancing contraction

96
Q

Thus, Digoxin exerts what type of inotropic effect?

A

Positive inotropic effect

97
Q

Digoxin is also a vagomimetic agent, meaning it

A

Slows SA and AV conduction and sensitizes broreceptors

98
Q

Increases afferent inhibitory activity which reduces activation of the sympathetic nervous system (SNS) afferents which up-regulate heart rate and vasoconstriction

A

Digoxins effect on baroreceptors

Cardiovascular and Pulmonary (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions