Why our heart beat sounds like "LUB" and "DUB". What does it mean?

Answer 1

With the aid of a stethoscope you can hear the characteristic sounds of the normal heartbeat, typically described as a "lub-dub." These sounds are produced by the closure of the heart valves. The first heart sound or "lub" results from closure of the tricuspid and mitral valves. It is a rather low-pitched and a relatively long sound which, as indicated in, represents the beginning of ventricular systole.

The second heart sound, or "dub," marks the beginning of ventricular diastole. It is produced by closure of the aortic and pulmonary (pulmonic) semilunar vanes when the intraventricular pressure begins to fall. This "dub" sound is typically heard as a sharp snap because the semilunar valves tend to close much more rapidly than the AV valves. Because diastole occupies more time than systole, a brief pause occurs after the second heart sound when the heart is beating at a normal rate. Therefore, the pattern that one hears is one of: "lub-dub" pause, "lub-dub" pause, and so on.

Sometimes, especially in young normal individuals, a third heart sound can be heard. This sound is produced by the very rapid influx of blood into the partially filled ventricle. It is typically very faint and as such difficult to hear.

Answer 2

Heart Sounds Lub Dub

Answer 3

The cardiac cycle consists of three phases:
a)atrial systole
b)ventricular systole
c)common diastole
The 2nd phase involves the simultaneous relaxation of atrium(auricles) & contraction of ventricles.Due to due to ventricular systole the blood pressure in ventricles is increased and therefore the tricuspid and the bicuspid valve close shut with a loud 'LUB' sound preventing the back flow of blood into the auricles and so the blood is pushed into the aorta

In the 3rd phase, as the atria are already in diastole after ventricular systole all the chambers of the heart enter the common diastolic phase for 0.4 s.During this time the pressure in the aorta is more than that in the ventricles and so the semi-lunar valves at the base of the arteries close shut with a lighter 'DUB' sound, thus preventing the back flow of blood from the arteries to the ventricles

Answer 4

Nainap and Allen are both correct, but a little deep in their explanations. Basically, your heart is pumping blood in two different directions, but alternate between the two. The "lub" is on the low pressure side and the "dub" is on the high pressure side. Kind of like a pump that creates pressure as it forces a liquid through a pipe, as opposed to a second pump that is sucking the liquid out of another pipe.

Answer 5

They are the normal sounds and mean that the heart is doing its job well. If you are worried, should see a doctor.

Answer 6

it is nothing but pumping of blood from vanes to heart and heart to vanes after purification.