Answered

Thanks to the Doppler effect, we can calculate the velocity at which blood is moving through the aorta. The average velocity over multiple heartbeats is measured in cm/sec, and the cardiac output is measured in cm³/sec. Once that is known, what other parameter is important to calculate the cardiac output?

a) The volume of the left ventricle, measured in cm³
b) The length of the aorta, measured in cm
c) The cross-sectional area of the aorta, measured in cm²
d) The volume of the left atrium, measured in cm³



Answer :

GinnyAnswer
To determine the cardiac output, which is the volume of blood being pumped by the heart per unit time (measured in cm³/sec), we need to correctly identify the parameters involved in the calculation.

Cardiac output [tex]\( Q \)[/tex] can be calculated using the formula:
[tex]\[ Q = A \times v \][/tex]
where:
- [tex]\( A \)[/tex] is the cross-sectional area of the aorta (measured in cm²).
- [tex]\( v \)[/tex] is the velocity of blood flow (measured in cm/sec).

Given the options:
a) The volume of the left ventricle, measured in cm³, does not directly contribute to calculating cardiac output in the equation mentioned.
b) The length of the aorta, measured in cm, is not needed for this calculation.
d) The volume of the left atrium, measured in cm³, is also irrelevant in this context.

Therefore, the correct parameter crucial for calculating the cardiac output is:
c) The cross-sectional area of the aorta, measured in cm².