Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cardiology > Lecture 10 - Cardiovascular responses to stress > Flashcards

Lecture 10 - Cardiovascular responses to stress Flashcards

1
Q

cardiac output equation

A

heart rate x stroke volume

usually 72 x 0.07 L = 5L/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a more ideal measurement than cardiac output?

A

mean arterial pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

mean arterial pressure equation

A

cardiac output x total peripheral resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is total peripheral resistance

A

how much vessels are squeezing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how does heart regulate itself to respond to changes?

A

increase preload - increase stroke volume
decrease in preload - decreases stroke volume
preload best measured as EDV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how is edv measured?

A

echo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does a very high preload result in

A

decrease in stroke volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what can increase the preload?

A

increase in circulating volume - overhydration/fluid
increase in central venous pressure - increases amount of blood in heart
eg. respiratory pump
decrease in venous compliance
increase in atrial filling or contraction - atrial fibrillation
decreased heart rate - prolongs diastole
increases in aortic or pulmonary pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Intrinsic regulation in cardiac function is done by what effect?

A

Bowditch effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the bowditch effect?

A

relationship between heart rate and cardiac performance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the bowditch effect suggest?

A

increase in heart rate - increase in force of contraction
decrease in heart rate - decrease in force
high levels of heart rate - eventually leads to a decreased force of contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is bowditch independent to frank-starling?

A

length of the muscle is not affected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does the extrinsic regulation of cardiac activity work?

A

autonomic - sympathetic and parasympathetic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the sympathetic nervous system supply importantly?

A

the heart, kidneys and the adrenal gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the parasympathetic system innervated

A

innervates the heart but not kidneys or suprarenal glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Sympathetic actions, the direct cardiac effects

A 
positive chronotropy on sa node
positive dromotropy (conduction) on AV node
Positive inotropy (contraction) ventricles and atria
positive lusitropy (relaxation) - ventricles and atria
17
Q

what are the systemic effects of sympathetic system

A

RAA system

Suprarenal stimulation - catecholamine release

18
Q

increase in chronotropy/ionotropy/preload

A

causes an increase in cardiac performance up to a certain point and then it will decrease

19
Q

Outline the RAAS

A

renin from the kidney converts angiotensinogen from the liver to angiotensin 1.
angiotensin 1 is converted to 2 by ACE.
angiotensin 2 acts on suprarenal glands to produce aldosterone (sodium and water retention) and on pituitary to secrete vasopressin (increase vasoconstriction) and acts on kidneys to increase sodium and water retention.

20
Q

what does aldosterone do

A

causes sodium and water retention

21
Q

what does vasopressin do

A

promotes water retention by acting on the aquaporins in the collecting duct of the nephrons

22
Q

actions of raas on stroke volume

A

increases central venous pressure by an increase in circulating fluid and increase in cardiac output

23
Q

What contributes to total peripheral resistance

A

vasoconstriction, increases BP

24
Q

which direct action on the suprarenal glands causes an increase in heart rate.

A

catecholamine release in the blood. leads to production of adrenaline by the suprarenal glands which acts on the kidney to secrete renin and so on…
adrenalin - vasoconstrictor - effects peripheral resistance
increases heart rate and stroke volume

25
Q

What are the parasympathetic actions

A

decreased heart rate - chronotropy
decreased av conduction - dromotropy
decreased atrial contractility - inotropy
ventricular contractility - no significant effect
raas - no significant effect

26
Q

which parts does the parasympathetic system not have much effect on

A

ventricular contractility

raas - doesnt act on kidneys or suprerenal glands

27
Q

Where are the baroreceptors located

A

carotid sinus and aortic arch

28
Q

an increase in arterial pressure will result in

A

increased baroreceptor firing

29
Q

an increase in baroreceptor firing will cause

A

a decrease in sympathetic tone and an increase in parasympathetic tone

30
Q

a decrease in baroreceptor firing will cause

A

an increase in sympathetic and a decrease in parasympathetic tone

31
Q

What happens when someone experiences blood loss?

A

decrease in central venous pressure, decrease in stroke volume, decrease in cardiac output, decrease in arterial pressure, increase in baroreceptor firing leads to an increase in sympathetic tone, decrease in parasympathetic, increase in vascular resistance and an increase in venous tone.

32
Q

poor urine output is indicative of

A

lack of blood flow to the kidnets

33
Q

What does giving fluids do to someone with blood loss

A

increases preload, increases central venous pressure increases stroke volume

34
Q

What does giving too much fluid to a person with blood loss do?

A

the preload becomes too high above threshold and too much stretch of muscle stroke volume decreases again and decreased cardiac output and mean arterial pressure

35
Q

What does an excess left ventricular pressure do?

A

back pressure to lungs - increase in alveolar capillary pressure. imbalance in mechanical pressure in alveoli and vessel and tissue compartments which causes pulmonary oedema and enlarged heart

36
Q

normal thoracic diameter

A

when horizontally measured - around half of the cavity.

37
Q

what sort of treatment would you give for pulmonary oedema and increased blood fluid.

A

furosemide (diuretics)

too much fluid in system - need to get rid of it. treat rapidly

38
Q

cardiopulmonary testing

A

exercise ECG, treadmill, metabolic cart, sphygmomanometer, rebreathing bag for non-invasive CO

39
Q

What does VO2 max indicate?

A

overall function of cardiovascular system, overall heart function, maximum amount of oxygen delivered to the tissues.

Cardiology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions