Control of CO- Exam 1

Question 1

Cardiac output

Answer 1

sum of blood flow to all tissues of the body

Question 2

Venous return

Answer 2

amount of blood flowing from tissues into the right atrium

Question 3

What is CO affected by?

Answer 3

overall metabolic activity of body including exercise
Body mass (CO vs CI)
Age

Question 4

What is CO controlled by?

Answer 4

Venous return (i.e. how peripheral circulation affects the flow of blood from tissues into the RA)

Question 5

What is the highest rate of metabolism from birth to about 10 years of age?

Answer 5

4.0 L/min/m2

Question 6

What does the CI decrease to with age?

Answer 6

2.4 L/min/m2 @ 80 y/o

Question 7

Why does CI decrease with age?

Answer 7

Decreasing muscle mass and overall decrease in activity

Question 8

Healthy Young Male CO

Answer 8

5.6 L/min

Question 9

Healthy Young Female CO

Answer 9

4.9 L/min

Question 10

Average CO for resting adult

Answer 10

5.0 L/min

Question 11

Average adult wt

Answer 11

70 kg

Question 12

Average surface area adult

Answer 12

1.7 m2

Question 13

Average cardiac index

Answer 13

3 L/min/m2

Question 14

What are increased levels of CO caused by?

Answer 14

Increased levels of nervous tone (sympathetic)
Hypertrophy
(Changes in contractility and HR)

Question 15

What are decreased levels of CO caused by?

Answer 15

Variety of problems ex. CAD, cardiac failure, pathologies

Question 16

Normal RAP/CO (Resting values)

Answer 16

RAP = 0mmHg
CO= 5 L/min

Question 17

Hypereffective heart (nervous response) 
Max Values

Answer 17

RAP >= 4 mmHG

CO =25 L/min

Question 18

Normal RAP/CO (Max Values)

Answer 18

RAP >=4 mmHg

CO= 13 L/min

Question 19

Hypereffective heart (hypertrophy) 
Max values

Answer 19

RAP > = 4 mmHg

CO = 30-40 L/min

Question 20

What does muscle mass increase by in hypereffective heart (hypertrophy)

Answer 20

50 to 75 %

Question 21

What does CO increase by in hypereffective heart (hypertrophY)

Answer 21

60 to 100 %

Question 22

What do the max values represent?

Answer 22

Summation of nervous response and hypertrophy

Question 23

A 2 mmHg increase in intrapleural pressure means what?

Answer 23

It will take an additional 2 mmHg to fill the RA

Curve shifts to the right

Question 24

What factors alter external pressure?

Answer 24

Cyclic changes in respiration
Breathing against negative pressure (shifts left)
Postiive pressure breathing (shifts right)
Opening thoracic cage (intrapleural pressure = 0mmHg) shifts curve to right 4 mmHG
Cardiac tamponade

Question 25

How many mls will fill systemic vascular system without stretching vessels giving overall pressure of 0?

Answer 25

3560 mls

Question 26

What is the normal systemic volume?

Answer 26

4500 mls

Question 27

Adding 1000 mls to the 3500 mls will produce what change in pressure?

Answer 27

7 mmHg (1000 mls / 140 mls/mmHg)

Question 28

What’s another name for mean systemic filling pressure?

Answer 28

Mean circulatory filling pressure

Question 29

What is the resistance created by veins?

Answer 29

2/3

Question 30

What is the resistance created by arterioles/small arteries?

Answer 30

1/3

Question 31

What is the venous return equation

Answer 31

VR = Psf - RA/ Ven Resistance

Question 32

What is the normal pressure in the central venous compartment?

Answer 32

0 mmHg

Question 33

What causes a shift in cardiac function curve?

Answer 33

Change in cardiac effectiveness

Change in external pressure

Question 34

What causes a shift in venous function curve?

Answer 34

Change in mean systemic filling pressure

change in venous resistance

Question 35

What is the C for arteries?

Answer 35

2 ml/ mmHg

Question 36

What is the C for veins?

Answer 36

110 ml/mmHg