Cardiovascular System (Part 2) Flashcards Preview

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Flashcards in Cardiovascular System (Part 2) Deck (178)
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1

What are the 7 phases of the cardiac cycle?

1) atrial systole
2) isovolumetric ventricular contraction
3) rapid ventricular ejection
4) reduced ventricular ejection
5) isovolumetric ventricular relaxation
6) rapid ventricular filling
7) reduced ventricular filling or diastasis

2

What 2 major events occur during atrial systole?

- atria contraction
- final phase of ventricular filling

3

What portions of an EKG are represented by atrial systole?

P wave and PR interval

4

What sound does the heart make during atrial systole?

the fourth heart sound

5

What 3 major events occur during isovolumetric ventricular contraction?

- ventricle contraction
- ventricular pressure increases and reaches maximum
- ventricular volume is constant

6

What portion of an EKG is represented by isovolumetric ventricular contraction?

QRS complex

7

What valves are closed during isovolumetric ventricular contraction?

all valves

8

What sound does the heart make during isovolumetric ventricular contraction?

the first heart sound

9

What 5 major events occur during rapid ventricular ejection?

- ventricle contraction
- ventricular pressure increases and reaches maximum
- ventricles eject blood into arteries
- ventricular volume decreases
- aortic pressure increases and reaches maximum

10

What portion of an EKG is represented by rapid ventricular ejection?

ST segment

11

What valve opens during rapid ventricular ejection?

aortic valve

12

What 3 major events occur during reduced ventricular ejection?

- ventricles eject blood into arteries at a slower rate
- ventricular volume reaches minimum
- aortic pressure starts to fall as blood runs into arteries

13

What portion of an EKG is represented by reduced ventricular ejection?

T wave

14

What 3 major events occur during isovolumetric ventricular relaxation?

- ventricular relaxation
- ventricular pressure decreases
- ventricular pressure is constant

15

What valve closes during isovolumetric ventricular relaxation?

the aortic valve

16

What sound does the heart make during isovolumetric ventricular relaxation?

the second heart sound

17

What 4 major events occur during rapid ventricular filling?

- ventricular relaxation
- ventricles fill passively with blood from atria
- ventricular volume increases
- ventricular pressure is low and constant

18

What valve opens during rapid ventricular filling?

mitral valve

19

What sound does the heart make during rapid ventricular filling?

the third heart sound

20

What 2 major events occur during reduced ventricular filling or diastasis?

- ventricles relax
- final phase of ventricular filling

21

What is blood flow driven by?

the difference in pressure between the arterial and venous sides of the circulation

22

What is the driving force for blood flow?

mean arterial pressure

23

At what level should mean arterial pressure be maintained at?

A high, constant level of approximately 100 mm Hg (set point)

24

Mean arterial pressure = pressure in what artery?

the aorta

25

How do you calculate mean arterial pressure?

Cardiac output times total peripheral resistance

26

What happens to mean arterial pressure if cardiac output is halved? Explain why...

Mean arterial pressure decreases, but it will not be halved because there is a compensatory increase in total peripheral resistance

27

What are the 2 major systems in which mean arterial pressure is regulated?

- baroreceptor reflex (fast)
- renin-angiotensis-aldosterone system (slow)

28

The baroreceptor mechanisms are fast, _____ mediated reflexes

neurally

29

How do the baroreceptor mechanisms attempt to keep arterial pressure constant?

via changes in the output of the sympathetic and parasympathetic nervous systems to the heart and blood vessels

30

Pressure sensors located within the walls of the carotid sinus and aortic arch are called what?

baroreceptors