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Read the following statements and select...

Read the following statements and select the correct option.
A. Damage to chordae tendinae of semilunar valves in aorta causes back flow of blood in left ventricle.
B. Closure of atrio-ventricular valves during ventricular systole generates first heart sound.

A

Both statements are correct

B

Only statement A is correct

C

Only statement B is correct

D

Both statements are incorrect

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to evaluate the two statements provided and determine their correctness. ### Step 1: Analyze Statement A **Statement A:** "Damage to chordae tendinae of semilunar valves in aorta causes back flow of blood in left ventricle." - **Understanding Chordae Tendinae:** Chordae tendinae are fibrous cords that connect the papillary muscles to the atrioventricular (AV) valves (mitral and tricuspid valves). They help prevent the valves from inverting during ventricular contraction. - **Semilunar Valves:** The semilunar valves (aortic and pulmonary valves) do not have chordae tendinae. Instead, they are structured to prevent backflow of blood into the ventricles after contraction. - **Conclusion for Statement A:** Since chordae tendinae are not associated with semilunar valves, this statement is incorrect. ### Step 2: Analyze Statement B **Statement B:** "Closure of atrio-ventricular valves during ventricular systole generates first heart sound." - **Understanding Heart Sounds:** The first heart sound (S1), often described as "lub," occurs when the AV valves (mitral and tricuspid) close at the beginning of ventricular systole. - **Mechanism:** This closure prevents the backflow of blood into the atria and is a normal part of the cardiac cycle. - **Conclusion for Statement B:** This statement is correct as it accurately describes the physiological event that generates the first heart sound. ### Final Conclusion - Statement A is incorrect. - Statement B is correct. Thus, the correct option is that **only Statement B is correct.** ---
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Read the following statement and choose the correct option. A. The first heart sound (lub) is associated with the closure of both semilunar valves. 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.

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Knowledge Check

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    B
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    C
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