Regulation of Cardiac Output

Question 1

What is the equation for cardiac output?

Answer 1

mean arterial pressure divided by peripheral resistance
OR
Stroke volume X heart rate

Question 2

Cardiac index peaks and then reduces when?

Answer 2

by age around 12

Question 3

Cardiac output is linearly related to (blank)

Answer 3

stress or exercise

Question 4

increase preload you will increase (blank)

Answer 4

rate of contraction

Question 5

If you increase atrial pressure you will increase (blank)

Answer 5

ventricular output

Question 6

inside the chest there is a normal (blank) intrapleural pressure

Answer 6

negative

Question 7

During inspiration the intrapleural pressure becomes more positive or more negative?

Answer 7

more negative

Question 8

When afterload increases, cardiac output

blank

Answer 8

decreases

Question 9

What normalizes Cardiac output (CO) with respect to body mass and the fact that CO changes with age?

Answer 9

cardiac index

Question 10

The cardiac function curve can only be shifted

up by two mechanisms:

Answer 10

1) sympathetic stimulation
(increase in heart rate and cardiac contractility), and
2)cardiac hypertrophy or increased cardiac mass through growth

Question 11

The more negative your interpleural pressure the more negative your (blank)

Answer 11

atrial pressure is

Question 12

The cardiac function curve is highly
dependent on extracardiac pressures,
which originates mainly from (blank)

Answer 12

intrapleural pressure.

Question 13

This negative pressure inside the chest has a major

impact on cardiac function as well as venous return because it determines the (blank)

Answer 13

pressure in the
right atrium and thus the pressure gradient (and filling pressure) between the venous system and
the heart.

Question 14

When you reach 175 bpm your cardiac output will start to decrease, why?

Answer 14

the ventricle isnt filling properly and starts to not pump which lowers your ejection fraction

Question 15

as you increase right atrial pressure you will decrease what?

Answer 15

venous return

Question 16

Why can you still get venous return when you have no pressure gradient?

Answer 16

because you still have blood in your cardiovascular system

Question 17

Why is there a pleteau of venous return at very negative atrial pressures?

Answer 17

Becase of partial collapse of the large veins entering the thorax due to large negative pressures

Question 18

cardiac output increases with (blank)

Answer 18

atrial pressure

Question 19

Venous return decrease with (blank)

Answer 19

atrial pressure

Question 20

Working cardiac output is where venous return curve meets (blank)

Answer 20

cardiac output curve

Question 21

the more resistance the less (blakn)

Answer 21

venous return

Question 22

The lower the venous pressure the lower the (blank)

Answer 22

venous return

Question 23

Venous return must match (blank)

Answer 23

cardiac output

Question 24

increase cardiac output increases capillary pressure, sending more fluid to the (blank)

Answer 24

tissues

Question 25

the cardiac output curve depicts Frank-starling relationship for ventricle and shows the CO is a function of (blank)

Answer 25

diastolic end volume

Question 26

The vascular function curve (venous return) shows the relationship between blood flow through venous return and (blank0

Answer 26

atrial pressure

Question 27

(blank) is the point at which the vascular function curve intersects the X-axis.

Answer 27

Mean systemic pressure

Question 28

When is mean systemic pressure decreased?

Answer 28

decrease blood volume, increase in venous compliance ( left shift venous return curve)

Question 29

WHat is the slope of the venous return curve determined by?

Answer 29

resistance of veins (2/3) and arterioles

Question 30

If increased total peripheral resistance of venous return you will get a venous return curve that is a

Answer 30

counterclockwise rotation

Question 31

If you give positive breathing (assisted respiration) what will happen to your cardiac output curve/

Answer 31

shifted to right

Question 32

If you make your interpleural pressure more negative how will it change your cardiac output curve

Answer 32

will shift it to the left

Question 33

if you increase mean systemic pressure you will reach a new (blank)

Answer 33

steady state

Question 34

if you increase cardiac contractility you will increase (blank)

Answer 34

venous return

Question 35

if you have a stiffer heart you will have decreased compliance so you will have a (blank)slope on a pressure scale

Answer 35

steeper slope

Question 36

If you ave a more dilated heart you will have a (blank) slope on a pressure scale

Answer 36

flatter

Question 37

What affects diastolic filling

Answer 37

filling pressure, ventricular compliance, and filling time

Question 38

What affects systolic ejection?

Answer 38

arterial pressure and myocardial contractility

Question 39

What affects cardiac ouput?

Answer 39

heart rate and stroke volume