Why is the second heart sound louder than the first?

The loudness of each component of the second heart sound is proportional to the respective pressures in the aorta and pulmonary artery at the onset of diastole. Dilatation of the aorta or pulmonary artery may also cause accentuation of the aortic and pulmonic components, respectively.

Why are the first and second heart sounds different in intensity?

The first heart sound has slightly greater intensity than the second heart sound. The first heart sound is produced by the closing of the mitral and tricuspid valve leaflets. The second heart sound is produced by the closing of the aortic and pulmonic valve leaflets.

Is S1 louder than S2?

Normally S1 is louder than S2 at the apex. The loudness of the mitral valve closure depends upon 3 things: the degree of valve opening (whether it has had time to passively swing shut because of heart block), the force of ventricular contraction shutting the valve, and.

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Why is the lub sound louder?

Identify: S1 – The first heart sound (lub) can be heard the loudest at the mitral area. This sound represents the closure of the mitral and tricuspid valves and is a low pitched, dull sound at the beginning of ventricular systole.

In which listening point the second sound is louder than the first?

In the first and fourth listening points first heart sound is louder than second one S1 > S2, in the second and third – second heart sound is louder than the first S1 < S2, the second sound over aorta and pulmonary artery is of the same loudness A2 = P2.

What is the difference between first heart sound and second heart sound?

S1 is normally a single sound because mitral and tricuspid valve closure occurs almost simultaneously. Clinically S1 corresponds to the pulse. The second heart sound (S2) represents closure of the semilunar (aortic and pulmonary) valves (point d).

Which heart sound is louder after exercise?

The intensity of the first sound is greater than the second. In a normal heart S1 is louder than S2 in the apex, and S2 is louder than S1 in the base. Compare the sounds from apex to base of the heart. S1 is generated by closure of mitral and tricuspid valves and they are close to the apex of heart.

What heart sound is the loudest?

Normally the first (S1) and second (S2) heart sounds are loudest and are audible in all normal animals. S1 is audible at the onset of mechanical systole and occurs in association with closure of the atrioventricular valves. S2 is heard at the end of systole with closure of the semilunar valves (see Fig. 1.5).

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Where does S2 sound loudest?

Normally, S1 is louder than S2 at the apex, and softer than S2 at the base of the heart.

What causes the first heart sound?

The first heart sound (S1) is produced by vibrations generated by closure of the mitral (M1) and tricuspid valves (T1). It corresponds to the end of diastole and beginning of ventricular systole and precedes the upstroke of carotid pulsation.

Why does the second heart sound occur after the T wave?

The second heart sound, called S2, makes a “dub” sound caused by the closure of the semilunar (aortic and pulmonary) valves following ventricular systole. S2 is split because aortic valve closure occurs before pulmonary valve closure.

Why is the first heart sound loud in mitral stenosis?

Upon auscultation of an individual with mitral stenosis, the first heart sound is usually loud and may be palpable (tapping apex beat) because of increased force in closing the mitral valve. The first heart sound is made by the mitral and tricuspid heart valves closing.

What action causes the second heart sound heard through a stethoscope?

The second heart sound, called S2, makes a “dub” sound caused by the closure of the semilunar (aortic and pulmonary) valves following ventricular systole. S2 is split because aortic valve closure occurs before pulmonary valve closure.

When does second heart sound occur?

The vibrations of the second heart sound occur at the end of ventricular contraction and identify the onset of ventricular diastole and the end of mechanical systole.

Which of the following events result in the second heart sound?

Second Heart Sound (S2) The second heart sound is produced by the closure of the aortic and pulmonic valves. The sound produced by the closure of the aortic valve is termed A2, and the sound produced by the closure of the pulmonic valve is termed P2.

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