Cardiac Output L10 Flashcards
What is the cardiac cycle?
All things that are associated with ONE heartbeat
Forces blood from areas of High pressure –> to areas of low pressure
What is the concept of Supply and Demand in Cardiac Output?
CO is supply
Metabolising Tissue, muscle and/or organs are the consumers which Demand energy and therefore demand O2, which is supplied by the heart’s blood
-their demand is due to their biochemical processes which need energy and therefore creates demand
The Heart’s supplying of this demand = CO
increased demand = increased HR
The hearts job is to supply (O2) based on/in response to demand (energy needs of metabolising tissue)
What is the job of the heart?
The heart’s job is to supply (O2) based on/in response to demand (energy needs of metabolising tissue)
What is CO supply or demand?
CO is the hearts supply (due to demand/controlled by metabolising tissue demand)
Why does metabolising tissue have demand?
Due to their biochemical processes which need energy, Therefore to get this energy they need O2 (demand) (and is supplied by the heart)
Why does the heart generate pressure?
To drive blood through the circuits and mediate flow into the aorta in particular
What is the equation for cardiac output?
CO = HR x SV CO(Lmin-1) = bpm x mLbeat-1
What is CO?
Cardiac output
The volume of blood ejected into the aorta(from the LV) per minute
Lmin-1
(-note: has to include LV and aorta, as we are talking about the genuine amount actually leaving the heart, not just being pumped - R is not systemic)
-effectively we pump out/our CO is just over our total blood volume (5L) every minute
–CO=HRxSV= 70bpm x 75mLbeat= 5.25Lmin-1
=supply is CO, and is based on demand
- Venous return is linked to CO
Venous return in the volume of blood returning from the vasculature, into the heart every minture
What is the rate of CO at rest?
approximately our entire blood volume (5L) get pumped right around out body every minute
CO = HR x SV = 70bpm x 75 mLbeat-1 = 5.25Lmin-1
because at rest CO is between 4-7 Lmin-1
What is CO cardiac output linked to?
Venous return
venous return is linked to CO
-venous return is the volume of blood returning form the vasculature, into the heart every mintue
What is venous return?
the volume of blood returning form the vasculature, into the heart every minute
-is linked to CO
Is cardiac output linked to anything?
Venous return
What is venous return linked to?
CO
Wha tis the volume of blood ejected into the aorta (From the LV) per minute?
Cardiac output
Lmin-1
(-note: has to include LV and aorta, as we are talking about the genuine amount actually leaving the heart, not just being pumped - R is not systemic)
What is the unit for CO?
Lmin-1
What is Lmin-1 the unit for?
Cardiac output
What is SV?
Stoke Volume
Lbeat-1
The volume of blood ejected by the ventricle during each contraction
SV=EDV-ESV
What is the unit for SV?
Lbeat-1
What is Lbeat-1 for?
SV
What is the volume of blood ejected by the ventricle during each contraction?
SV stroke volume
(each contraction=each beat)
Lbeat-1
What is the equation for SV?
EDV-ESV
What does EDV-ESV equal?
SV
SV = EDV-ESV
What is HR?
Heart Rate
beatsmin-1
the number of heart beats per minute
Increase in demand = increase in HR
What happens if there is an increase in demand?
Increase in HR