A&P CV2 Loops previous semester Flashcards Preview

Fall'20 A&P III > A&P CV2 Loops previous semester > Flashcards

Flashcards in A&P CV2 Loops previous semester Deck (81)
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1
Q

Ventricular pressure -volume loops demonstrate the changes in

A

Intraventricular volume and pressure during normal cardiac cycle

2
Q

How many steps are in the ventricular loop cycle?

A

4

3
Q

Isovolumetric Contraction Step 1 (B-> C) Happens just after

A

the QRS

4
Q

Isovolumetric Contraction is the period between _____ and _____.

A

Mitral valve closing and aortic valve opening

5
Q

Mitral valve closing and aortic valve opening occurs in what phase of loop cycle?

A

Isovolumetric contraction

6
Q

What period has the highest O2 consumption?

A

Isovolumetric contraction

7
Q

Isovolumetric contraction CYCLE begins

A

during diastole (at point B)

8
Q

The left ventricle is filed with blood from teh left atrium (vol = 140ml) during what cycle?

A

Isovolumetric contraction

9
Q

During Isovolumetric contraction, what does the ventricular pressure do? why?

A

Pressure increases b/c the valves are closed and the ventricle is filling.

10
Q

Isovolumetric contraction follows what law?

A

Laplace’s Law

11
Q

Laplace’s Law is (equation)

A

T=Pr

12
Q

T=Pr

A

Laplace’s law

13
Q

What part of the loop cycle follows Laplace’s Law?

A

Isovolumetric Contraction (B to C)

14
Q

What is the ventricular end -diastolic volume?

A

~ 140ml

15
Q

Cycle 2 of the ventricular P-Vol Loop is

A

Ventricular Ejection (C to D) or “emptying”

16
Q

Ventricular Ejection is what cycle of the P-Vol loop?

A

cycle 2 (C to D)

17
Q

Cycle 2, Ventricular Ejection is the period between what opening and closing?

A

aortic valve opening and closing

18
Q

at what point (A, B, C, D) does the aortic valve open?

A

C

19
Q

The aortic valve opens when pressure in …

A

the left Ventricle exceeds pressure in the aorta.

20
Q

When the left Ventricle exceeds pressure in the aorta what happens? Where do we see this on the loop graph?

A

The aortic valve opens

See at point C

21
Q

During Cycle 2, Ventricular Ejection blood is ejected into the aorta, and Ventricular Vol does what?

A

decreases

22
Q

The volume ejected during cycle 2 from the ventricle is known as the:

A

Stroke Volume

23
Q

Stroke volume can be measured on the P-Vol loop graph where?

A

The WIDTH of the loop

24
Q

The volume remaining in the left ventricle (at Point A) is:

A

end-systolic volume

25
Q

Equation for loop calculation of SV

A

SV = EDV - ESV

SV = EDV (point B) - ESV (point A)

26
Q

Equation for loop calculation of EF

A

EF = SV / EDV

[(point B - point A)/ point B]

27
Q

Cycle 3 of Ventricular P-Vol Loop is called

A

Isovolumetric relaxation

28
Q

Isovolumetric relaxation occurs at what cycle in the loop?

A

cycle 3 - point D to point A

29
Q

Isovolumetric relaxation is the period between

A

aortic valve closing and mitral valve opening.

30
Q

the period between aortic valve closing and mitral valve opening is known as:

A

Isovolumetric relaxation (D to A)

31
Q

What happens at point D?

A

the ventricle relaxes

32
Q

Where does the Ventricle relax on the loop? (what point)

A

D

33
Q

When the ventricle relaxes, what is happening?

A

The Ventricular pressure decreases to less than aortic pressure.

-Aortic valve closes.

34
Q

Why is cycle 3 Isovolumetric? What’s happening?

A

The aortic valve closes.

B/c all the valves close again, ventricular vol. is constant (isovolumetric)

35
Q

Ventricular Filling is what cycle of the P-Vol loop?

A

cycle 4. (A to B)

36
Q

Cycle 4 is called what?

A

Ventricular Filling (point A to B)

37
Q

Ventricular Filling (cycle 4) is the period just after what:

A

mitral valve opening (point A)

38
Q

What point does the Mitral valve open?

A

Point A

39
Q

At point D the ventricle

A

relaxes

40
Q

Once left ventricular pressure decreases to less than the left atrial pressure, what happens?

A

the Mitral (AV) valve opens and filling of the ventricle begins.

41
Q

During Ventricular Filling (cycle 4), ventricular volume increases to about:

A

140 ml (end-diastolic vol)

42
Q

What is occurring at Point B ?

A

end diastolic volume

ventricular volume increasing

43
Q

20% of ventricular filling is a result of the

A

atrial kick

44
Q

Atrial Kick occurs when?

A

at the end of cycle 4; just before point B

45
Q

Increased Preload refers to an

A

increase in ventricular End diastolic VOLUME (filling)

-result of increased venous return

46
Q

Frank-Startling relationship:

Increased preload =

A

increased stroke volume

47
Q

Increased SV is reflected on the P-Vol loop by

A

increased WIDTH

48
Q

Preload (ventricular) increases from:

A
  • exercise
  • increased blood vol (pregnancy, over transfusion)
  • excitement (sympathetic)
49
Q

Preload (ventricular) decreases from:

A
  • venodilators (ntg)

- diuretics (furosemide)

50
Q

**Preload = **

A

Pumps up the heart

51
Q

“Pumps up the Heart”

A

Preload

52
Q

Increased afterload refers to

A

an increase in aortic PRESSURE

53
Q

an increase in aortic PRESSURE refers to

A

increased afterload

54
Q

afterload is aka

A

diastolic arterial pressure

55
Q

diastolic arterial pressure is aka

A

afterload

56
Q

Afterload is proportional to

A

TPR (total peripheral resistance)

57
Q

Factors that increase afterload

A

HTN

Aortic Stenosis

58
Q

If the ventricle must eject blood against a higher pressure, what will decrease?

A

stroke volume

59
Q

Stroke volume is reflected on the P-Vol loop as the

A

width

60
Q

How would decreased SV change the P-Vol loop?

A

Decrease the width

61
Q

Decreased SV results in an increased

A

end systolic volume

62
Q

End systolic volume is the volume

A

left behind after systole

63
Q

We use what to decrease afterload?

A

vasodilators (hydralazine)

64
Q

Increased contractility develops when the ventricle has a greater tension than usual during systole.

Causing an increase in: (two things)

A

SV and EF

65
Q

Increased SV causes a decrease in

A

end systolic volume (ESV)

66
Q

Contractility (and SV) increase with:

A
  • catecholamines
  • increased intracellular Ca++
  • Digitalis (Increased Intracellular Na+ resulting in Increased intracellular Ca++)
67
Q

Contractility (and SV) decrease with:

A
  • Beta 1 blockade
  • HF
  • acidosis
  • hypoxia/ hypercapnia
68
Q
  • catecholamines
  • increased intracellular Ca++
  • Digitalis

All do what to Contractility/SV?

A

Increase it

69
Q
  • Beta 1 blockade
  • HF
  • acidosis
  • hypoxia/ hypercapnia

All do what to Contractility/SV?

A

Decrease it

70
Q

Visual Explain what changes in the ventricular P-vol loop graphically with increases in:
(A) Preload
(B) Afterload
(C) Contractility

A

A- preload; vol increases. loop expands to the right.
B- afterload; Pressure increases. loop increases in height; left side of loop vol decreases.
C- contractility; Vol increases to the left and a slight increase in pressure height

71
Q

SV is affected by (3 points)

A
  • contractility
  • afterload
  • preload

SV CAP

72
Q

Increased SV when Increased ___

A

Preload or Contractility

73
Q

Increased SV when decreased ____

A

afterload

74
Q

Decreased afterload does what to SV?

A

increases SV

75
Q

Increased Contractility does what to SV?

A

Increases SV

76
Q

Increased Preload does what to SV?

A

Increases SV

77
Q

constancy of CO up to a pressure level of

A

160 mmHg

78
Q

If pressure > 160mmHg; what happens to CO?

A

drops rapidly

79
Q

Nerves that stimulate Heart

A

Vagus

Sympathetic nerves

80
Q

Parasympathetic stimulation has a positive or negative effect on CO (curve)?

A

Negative

lowers the curve - lowering the RA pressure

81
Q

Sympathetic stimulation has a positive or negative effect on CO (curve)

A

Generally positive

-graphed curve: zero, Normal, and a GREAT Improvement/Increase of CO with Maximum sympathetic stimulation