NEET Solved Paper 2019 Question 26
Question: What would be the heart rate of a person if the cardiac output is 5L, blood volume in the ventricles at the end of diastole is 100 mL and at the end of ventricular systole is 50 mL? [NEET 5-5-2019]
Options:
A) 100 beats per minute
B) 125 beats per minute
C) 50 beats per minute
D) 75 beats per minute
Show Answer
Answer:
Correct Answer: A
Solution:
- To find the heart rate, we can use the formula for cardiac output (CO):
[ \text{CO} = \text{Heart Rate (HR)} \times \text{Stroke Volume (SV)} ]
First, we need to calculate the stroke volume (SV), which is the difference between the volume of blood in the ventricles at the end of diastole (EDV) and at the end of systole (ESV):
[ \text{SV} = \text{EDV} - \text{ESV} ] [ \text{SV} = 100 , \text{mL} - 50 , \text{mL} ] [ \text{SV} = 50 , \text{mL} ]
Next, we convert the cardiac output from liters to milliliters:
[ \text{CO} = 5 , \text{L/min} = 5000 , \text{mL/min} ]
Now, we can solve for the heart rate (HR):
[ \text{HR} = \frac{\text{CO}}{\text{SV}} ] [ \text{HR} = \frac{5000 , \text{mL/min}}{50 , \text{mL/beat}} ] [ \text{HR} = 100 , \text{beats/min} ]
So, the heart rate is:
BETA
