Which heart sound is associated with the closure of the mitral and tricuspid valves?
S3
S1
S2
S4
The Correct Answer is B
A. S3:
S3 occurs during rapid ventricular filling in early diastole and may indicate volume overload or heart failure, not AV valve closure.
B. S1:
S1 is produced by the closure of the mitral and tricuspid valves at the beginning of ventricular systole. It marks the start of ventricular contraction and is best heard at the apex (mitral) and lower left sternal border (tricuspid).
C. S2:
S2 occurs during closure of the semilunar valves (aortic and pulmonic) at the end of systole, not AV valves.
D. S4:
S4 occurs during atrial contraction in late diastole and is associated with a stiff ventricle; it is not related to AV valve closure.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
A. Between the left ventricle and aorta; prevents backflow of blood into the left ventricle:
This describes the aortic valve, not the mitral valve. The aortic valve prevents backflow from the aorta into the left ventricle. Confusing these can lead to misinterpretation of murmurs or heart sounds.
B. Between the right atrium and right ventricle; prevents backflow of blood into the right atrium:
This describes the tricuspid valve, which is on the right side of the heart. The mitral valve is on the left side.
C. Between the right ventricle and pulmonary artery; prevents backflow of blood into the right ventricle:
This describes the pulmonic valve, which is located at the right ventricular outflow tract, not the mitral valve.
D. Between the left atrium and left ventricle; prevents backflow of blood into the left atrium:
The mitral valve (also called the bicuspid valve) is located between the left atrium and left ventricle. Its primary function is to allow unidirectional blood flow into the left ventricle during diastole and prevent regurgitation into the left atrium during systole, maintaining efficient cardiac output.
Correct Answer is A
Explanation
A. Ventricular systole:
Semilunar valves (aortic and pulmonic) open when ventricular pressure exceeds arterial pressure during systole, allowing blood to be ejected into the aorta and pulmonary artery.
B. Isovolumetric relaxation:
During this phase, the ventricles relax and pressure falls, causing the semilunar valves to close to prevent backflow.
C. Atrial systole:
During atrial contraction, the AV valves are open to fill the ventricles; semilunar valves remain closed.
D. Ventricular diastole:
During diastole, the ventricles fill with blood, and the semilunar valves remain closed until the next systole.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.