Question

A healthy individual has the cardiac output of 5.5 L and heart rate of 72 beats per minute. The stroke volume of the individual is ........ mL.

Hint:

Cardiac output is the product of heart rate and stroke volume: \( CO = HR \times SV \). A stroke volume of 70 mL is typical for a healthy adult.

Answer 1

Correct Answer: 76 - 77

Step 1: Understanding cardiac output and stroke volume. 
Cardiac output (CO) is the volume of blood the heart pumps per minute, and it is calculated using the formula: \[ CO = \text{Heart rate (HR)} \times \text{Stroke volume (SV)} \] Given: - CO = 5.5 L/min - HR = 72 beats/min We need to calculate the stroke volume (SV) of the individual.

Step 2: Rearranging the formula to solve for stroke volume. 
Rearrange the formula to find SV: \[ SV = \frac{CO}{HR} = \frac{5.5 \, \text{L/min}}{72 \, \text{beats/min}} = \frac{5500 \, \text{mL/min}}{72 \, \text{beats/min}} = 76.39 \, \text{mL} \]

Step 3: Conclusion. 
The stroke volume is 76.39 mL.