Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
Read the following statements and choose the correct option:

A. The first heart sound (lub) is associated with the closure of both semilunar valves.
B. The duration between the adjacent second heart sound and first heart sound is 0.3 seconds
C. The cardiac output is the stroke volume multiplied by the number of heartbeats per minute.
BiologyBody Fluids and CirculationNEET
Options:
  • A A, B and C are correct
  • B A, C are correct but B is incorrect
  • C A is correct but B, C are incorrect
  • D A, B are incorrect but C is correct
Solution:
1716 Upvotes Verified Answer
The correct answer is: A, B are incorrect but C is correct
The first heart sound (lub) is associated with the closure of the tricuspid and bicuspid valves, which occurs at the beginning of ventricular systole of a cardiac cycle.

The duration between the adjacent second heart sound (dub) and first heart sound (lub) is 0.5 seconds.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.