If the aortal valve is closed at pressure

If the aortal valve is closed at pressure about 100 mm . , and the valve of a pulmonary artery - at pressure of an order of 20 mm hg why closing of the aortal valve occurs earlier? Components of the second warm tone appear simultaneously with corresponding on pressure curves in a pulmonary artery and in an aorta. On the other hand, it has been shown, that occurrence time is in turn bound to peripheric resistance to a blood flow. For example, than resistance and an elastic tension of pulmonary arterioles, and also the more capacity toradol injection of pulmonary arteries there is less, the will proceed more longly a blood flow and that will appear on a pressure curve in a pulmonary artery later. Resistance of pulmonary vessels makes about one tenth from size of peripheric vascular resistance. Force of an elastic tension of not changed pulmonary artery, apparently, is less, than the tension of walls of an aorta, and capacity of a pulmonary vascular bed exceeds volume of last. Thus, in relation to corresponding points of crossing of curves of pressure the blood flow in a pulmonary artery proceeds more longly, than in an aorta.
Therefore pressure decrease in a pulmonary artery and a closing snap of its valve (a pulmonary component) arise later, than on an aortal sphygmogram and an aortal component of the second warm tone. Notes: And. The excitation wave on spending system of heart comes to a left ventricle earlier, than to the right. Left ventricle reduction also begins little bit earlier. However it practically does not influence a time parity between the moments of occurrence of corresponding closing snaps. . At from heart of the general arterial trunk the unique valve theoretically cannot lead to occurrence of the split second warm tone. However when cusps are deformed or when their number more than three, splitting of the second tone rather possibly and even can be enlarged at inspiration height. The reason of such splitting is unknown. It is represented, that it can be true doubling of the second warm tone (earlier this term designated any split tone, until then it has not been established yet, that the second warm that is formed by two components which arise independently from each other on the aortal valve and on the valve of a pulmonary artery). Splitting of the second tone at the general arterial trunk can reflect the closing of the valve caused by various vascular resistance in small and big circles of a circulation or, probably, asynchronous baclofen overdose numerous cusps of the different size. Century At some healthy people have been described the split pulmonary component of the second warm tone which reason of occurrence also is unknown. PHYSIOLOGICAL MECHANISMS OF NORMAL RESPIRATORY DYNAMICS OF THE INTERVAL BETWEEN COMPONENTS OF THE SECOND WARM TONE 1. Well-known, that the interval between components of the second warm tone is enlarged on an inspiration and decreases on an exhalation. At the expense of what shift from components - aortal or pulmonary is occurs? At the expense of shift of both components. At an inspiration the pulmonary component arises later, and an aortal component - earlier, as leads to interval augmentation between them. The note: In all age groups, but in particular among persons is more senior 40 years, there can be healthy people at whom the aortal component of the second tone arises at a time without dependence from a breath phase. If the aortal component undergoes characteristic dynamics its shift defines no more than 30 from the general duration of an interval of splitting ( 4). The interval augmentation between components of the second warm tone (S2) on an inspiration in larger degree is defined by later occurrence of a pulmonary component (2), than earlier occurrence of an aortal component (2) 2. Than occurrence of a pulmonary component during an inspiration is caused more later? There are, at least, two explanations: And. During an inspiration intrathoracic pressure decreases and the right ventricle volume is enlarged. Thus lungs operate as pressure-blowing bellows. Differently, at a stretching lungs play a role of the pump which pumps over blood from venas cava in the right chambers of heart. The augmentation of volume of a right ventricle leads to later closing of the valve of a pulmonary artery since in the presence of a unique outlet opening it is required to a ventricle more time to expel additional quantity of blood. . On an inspiration the capacity of a small circle of a circulation is enlarged and, accordingly, vascular resistance decreases.