test 1

Question 1

CO is affected by

Answer 1

 Overall metabolic activity of body including exercise
 Body mass (Cardiac output versus Cardiac Index)
 Age

Question 2

what determines the CO

Answer 2

venous return and metabolic activity

Question 3

an increase in metabolic activity does what to CO, CI, and O2 consumption

Answer 3

increases all

Question 4

Increased VR produces

increase in what

Answer 4

-myocardial strength which increases SV and HR

Question 5

increase in metabolism does what to the SVR

Answer 5

• decreases arterial constriction and increases blood flow

- only if body maintains constant MAP

Question 6

What effect does the nervous system have on the CO and MAP

Answer 6

• with the nervous system, it keeps the MAP constant therefore allowing the CO to change appropriately with change in SVR and metabolism
• without nervous control, MAP decreases as SVR decreases with a small change in CO

Question 7

highest rate of metabolism peaks at what age

Answer 7

8-10 yrs

-4.0 L/min/m2

Question 8

what happens to CI with age

Answer 8

• decreases
• due to decreasing muscle mass and overall decrease in activity
• 2.4 L/min/m2 @ 80 years

Question 9

hypereffective

Answer 9

increased CO

Question 10

Hypoeffective

Answer 10

Decreased levels of CO

Question 11

causes of hypereffective heart

Answer 11

 Increased levels of nervous tone (sympathetic)

 Hypertrophy

Question 12

causes of Hypoeffective heart

Answer 12

• increased arterial pressure against which the heart must pump (severe hypertention)
• inhibition of nervous excitation of the heart
• coronary artery blockage causing a heart attack
• vascular heart disease

Question 13

Normal conditions (normal ANS tone) 
resting and max values of RAP and CO

Answer 13

 RESTING VALUES: RAP = 0 mmHg –> CO = 5 L/min

 MAX VALUES: RAP ≥ 4 mmHg –> CO = 13 L/min

Question 14

Hypereffective heart (nervous response)
max values of RAP and CO

Answer 14

 MAX VALUES: RAP ≥ 4 mmHg  CO = 25 L/min

Question 15

Hypereffective heart (hypertrophy)
max values of RAP and CO

Answer 15

 Increased muscle mass 50 to 75%
 Increase max CO 60 to 100%
 MAX VALUES: RAP ≥ 4 mmHg  CO = 30-40 L/min

Question 16

heart moves between levels of the cardiac functional curve based on what

Answer 16

-level of sympathetic tone

Question 17

if the intrapleural pressure goes up, what do you need to happen to maintain the same venous return

Answer 17

-a higher peripheral venous pressure (CVP)

Question 18

If the intrapleural pressure drops by 1.5, the right atrial pressure drops by what to maintain the same VR

Answer 18

1.5 mmHg

Question 19

cardiac tamponade

Answer 19

• constricts the heart

- heart becomes hypoeffective because it is unable to get enough preload into the heart

Question 20

to increase CO with cardiac tamponade

Answer 20

-need to increase RA pressure higher than zero

Question 21

with a hypereffective heart, which way does the curve shift?

Answer 21

-slightly to the left

Question 22

Breathing against negative pressure (ventillator) shifts curve to the

Answer 22

• left

- can get the same CO at a lower CVP

Question 23

Breathing against positive pressure shifts curve to the

Answer 23

• right

- it will take a higher CVP to get the same CO

Question 24

where is most of the volume of blood

Answer 24

-peripheral veins outside of the thorax

Question 25

anatomic volume

Answer 25

- filled without stretching | - no pressure

Question 26

how much volume can the body hold without causing pressure

Answer 26

3560 mls

Question 27

ventricle (diastole) Vo: compliance: resistance:

Answer 27

30 mls 24 ml/mmHg 0 mmHg/L/min

Question 28

arteries Vo: compliance: resistance:

Answer 28

600 mls 2 ml/mmHg 1 mmHg/L/min

Question 29

arterioles Vo: compliance: resistance:

Answer 29

100 mls 0 ml/mmHg 13 mmHg/L/min

Question 30

capillaries Vo: compliance: resistance:

Answer 30

250 mls 0 ml/mmHg 5 mmHg/L/min

Question 31

``` Peripheral Venous Compartment Vo: compliance: resistance: ```

Answer 31

2500 mls 110 ml/mmHg 1 mmHg/L/min

Question 32

``` Central Venous Compartment Vo: compliance: resistance: ```

Answer 32

80 mls 4 ml/mmHg 0 mmHg/L/min

Question 33

entire circuit Vo: compliance: resistance:

Answer 33

3560 mls 140 ml/mmHg 20 mmHg/L/min

Question 34

Mean systemic filling pressure (Psf)

Answer 34

- pressure when we have a normal volume and no blood flow | - adding 1000 mls to 3560 will produce an overall pressure of 7 mmHg (1000 mls/ 140 mls/mmHg)

Question 35

Mean Systemic Filling Pressure (Psf) versus Mean Circulatory Filling Pressure (Pmf)

Answer 35

 Pmf includes the pulmonary circulation which has minimal effect on overall value  Pmf ≈ Psf and will be used interchangeably

Question 36

where does the major resistance occur

Answer 36

-between the peripheral venous compartment and the central venous compartment

Question 37

normal peripheral venous compartment pressure

Answer 37

-usually equal to mean systemic filling pressure (7 mmHg)

Question 38

venous resistance

Answer 38

1.4 mmHg/L/min

Question 39

Normal central venous pressure

Answer 39

0 mmHg

Question 40

an increase in intrathoracic pressure causes what

Answer 40

-the IVC and SVC collapse causing a decrease in VR

Question 41

Decreasing circulating blood volume does what to the mean systemic filling pressure with a constant venous resistance

Answer 41

decrease in Psf and a shift to the left of the venous function curve

Question 42

at a given CVP, what will happen to the VR with a change in venous resistance

Answer 42

-at a lower resistance, there will be an increase in VR

Question 43

at a given CVP, what will happen to the VR with a change in venous resistance

Answer 43

-at a lower resistance, there will be an increase in VR

Question 44

Increased CVP causes

Answer 44

 increase Cardiac output  decrease Venous return  More volume leaves the central venous compartment than enters so CVP begins to decrease. Will continue until back at equilibrium