medicinal plants top





Clinical stethoscope is the commonest instrument used for detecting heart sounds. A stethoscope is having a bell and a diaphragm. The former picks up low pitched sounds better and the later is more useful to receive high pitched sounds. The individual is not usually conscious of his heart beat, but is the ear or a stethoscope is placed on the chest wall a little below the left nippe and slightly nearer the midline, heart beat can be heard.


The mitral, tricuspid, pulmonary and aortic areas are auscultated in order. These areas do not indicate the location of corresponding valves.

First heart sound (S1)

It occurs at the commencement of systole and coincides with the clossure of atrio ventricular valves. It is best heard over the left 5th intercostal space 1.27 cm inside the midclavicualr line. It coincides with R - wave of ECG.


Second heart sound (S2)

It marks the onset of diastole and indicates the closure of semilunar vales. The valves-aortic and pulmonary do not close simultaneously and the pulmonary pressure preceeds the aortic one. During inspiration, the sound is split into an aortic component and later a pulmonary component. Its occurance is at the end of T-wave of ECG . Clinical pulmonary area is 2nd left intercostal space close to sternum. Clinical aortic area is right 2nd intercostal area close to sternum.

Third heart sound (S3)

Occurs in the earliest part of diastole and it coinsides with the rapid ventricular filling.

Fourth heart sound (S4)

Produced by atrial contraction and it corresponds to the last rapid filling space or it denotes the end of diastole.



Write briefly on: 1. Mitral stenosis 2. Mitral regurgitation.

Periodic breathing: is irregular breathing with period of apnoea in between

Eg: Cheyne strokes breathing

This is characterised by waxing and waning type od breathing cycles followed by a period of apnoea. It is seen in congestive cardiac failure.

Biot’s breathing is another type of periodic breathing in which cycles of hyperventialtion with intermittent periods of apnoea occur.