Download cardiac-output

B – The Cardiovascular System
1. The structure and function of arteries,
capillaries and veins
2. The structure and function of the heart
3. Pathology of cardio vascular disease
(CVD)
4. Blood glucose levels and obesity
KA 6: The structure and function
of the heart
REVISION:
Structure
of the
heart
(A)
Cardiac function
and cardiac
output
2.6 Key
Topics
(B) Cardiac
cycle
(D) Blood
Pressure
(C)
The structure and
function of cardiac
conducting system
KA 6a: Learning Outcomes
• Define the terms ‘cardiac output’, ‘heart
rate’ and ‘stroke volume’
• State the formula for cardiac output
• Carry out cardiac output calculations
Key Terms
Heart Rate (pulse) (HR)
• Number of heartbeats that occurs per minute.
Stroke Volume (SV)
• Volume of blood expelled by each ventricle on contraction.
(The stronger the contraction, the greater the stroke
volume).
Cardiac Output (CO)
• The volume of blood pumped through each ventricle per
minute. (creates the pulse)
• CO = HR x SV
The left and right ventricles pump the same volume
of blood through the aorta and pulmonary artery.
Calculations
CO = HR x SV
A: 5.8/60 = 0.09
B: 6.1/68 = 0.08
C: 7.2/72 = 0.1
D: 7.6/78 = 0.09
ANSWER: C
Calculations
CO = HR x SV
The graph below shows how pulse rate and stroke volume
change with the rate of oxygen uptake
1. What is the
cardiac output
when the
oxygen uptake
is 0.6 L/min ?
2. What is the
cardiac output
when the
oxygen uptake
is 1.6 L/min?
Calculations
CO = HR x SV
The graph below shows how pulse rate and stroke volume
change with the rate of oxygen uptake
1. What is the
cardiac output
when the oxygen
uptake is 0.6
L/min ?
When oxygen uptake =
0.6…
HR = 80 and SV = 120
• BUT we need to change
120 cm3 into L (/1000)
CO = HR x SV
CO = 80 x 0.12
CO = 9.6 L/min
Calculations
CO = HR x SV
The graph below shows how pulse rate and stroke volume
change with the rate of oxygen uptake
1. What is the
cardiac output
when the oxygen
uptake is 1.6 L/min
?
When oxygen uptake =
1.6…
HR = 110 and SV = 150
• BUT we need to change
150 cm3 into L (/1000)
CO = HR x SV
CO = 110 x 0.15
CO = 16.5 L/min
KA 6a: Learning Outcomes
• Define the terms ‘cardiac output’, ‘heart
rate’ and ‘stroke volume’
• State the formula for cardiac output
• Carry out cardiac output calculations