Переведите.. when we listen to the heart we canhear two sounds. the third sound is also heard in some young persons before the age of 30. the first heart sound is the longest one. it is heard at the moment of contraction of the ventricles when the atrio - ventricular valves close. the second sound lasts for a shorter period of time. it is heard at the moment when the pulmonary and aortic semilunar valves close. the third heart sound is heard when the blood is passing from the atria into the ventricles. the first and often over the large vesseles. the first heart sound is greater over the surface of the ventricles and it is the gratest over the surface of the mitral and tricuspid valves. the second heart sound is heard loudest over the aorta and the pulmonary artery. heart sounds are also heard over some portions of the chest. normally the first heart sound is heard best over the apex of the heart in the fifth costal interspace. the second sound is heard best over the pulmonary artery and the aorta, that is in the second left and right costalinterspaces. the aortic sound is normally louder than the pulmonic sound.
