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Y2S1 CARDIO. > Control of Cardiac Output > Flashcards

Flashcards in Control of Cardiac Output Deck (17)
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1
Q

cardiac output

A

Stroke volume x heart rate

2
Q

Intrinsic mechanisms that control stroke volume

A

– Self-regulation
– Frank-Starling mechanism
– ↑EDV↑ force of contraction

3
Q

Preload

A

– Venous pressure and venous return to heart (end diastolic pressure, EDP)

4
Q

Afterload

A

– Aortic/pulmonary artery pressure

5
Q

Extrinsic mechanisms that control cardiac output

A

– Sympathetic nerves

6
Q

Frank-Starling’s Law of the Heart

A

Allows for automatic adjustment for small imbalances between the left ventricle and right ventricle.

  • Automatic balancing between CO from left-side of heart to volume returning to right-side.
7
Q

Pressure in the systemic and pulmonary vessels

A

small occelations in the left atrium
large occelations in the left ventricle which decreases from the Aorta to the arterioles then in the capillaries there is none in the capillaries

8
Q

Vascular compliance

A

compliance decreases with age and vasoconstriction

9
Q

Non-compliant:

A

rigid tubes resist expansion when internal pressure rises

capillaries, arterioles etc.

10
Q

Compliant:

A

tubes with elastic walls swell when internal pressure rises etc. arteries, veins

11
Q

Mean arterial blood pressure (MABP)

A

Diastolic pressure + 1/3 pulse pressure

12
Q

Pulse pressure

A

systolic pressure – diastolic pressure

13
Q

Factors determining the magnitude of pulse pressure

A

Stroke volume
Speed of ejection of stroke volume
Arterial compliance

14
Q

Stroke volume

A

– Intrinsic and extrinsic factors
– Remember afterload, preload, sympathetic
innervation

15
Q

Arterial compliance

A

– Decreases with age

• Arteriosclerosis

16
Q

Factors affecting flow of a fluid though a vessel

A
  • Viscosity
    – Vessel length
    – Vessel radius
17
Q

Arterial pressure

A

cardiac output x total peripheral resistance