Zero-stress states of human pulmonary arteries and veins

Abstract

The zero-stress states of the pulmonary arteries and veins from order 3 to order 9 were determined in six normal human lungs within 15 h postmortem. The zero-stress state of each vessel was obtained by cutting the vessel transversely into a series of short rings, then cutting each ring radially, which caused the ring to spring open into a sector. Each sector was characterized by its opening angle. The mean opening angle varied between 92 and 163 degrees in the arterial tree and between 89 and 128 degrees in the venous tree. There was a tendency for opening angles to increase as the sizes of the arteries and veins increased. We computed the residual strains based on the experimental measurements and estimated the residual stresses according to Hooke's law. We found that the inner wall of a vessel at the state in which the internal pressure, external pressure, and longitudinal stress are all zero was under compression and the outer wall was in tension, and that the magnitude of compressive stress was greater than the magnitude of tensile stress.

Characterization of agonist-induced vasoconstriction in mouse pulmonary artery

“…The zero-stress state after cutting was calculated as the angle () of opening of the resting artery. Despite evidence that the opening angles at the zero-stress states vary in third-to ninth-order human PA (27), we found that the opening angles at the zero-stress states were comparable between left and right branches of intrapulmonary arteries (94.2 Ϯ 9.10 vs. 88.2 Ϯ 7.6°; P ϭ 0.6218).…”

Manual pressure distension of the human saphenous vein changes its biomechanical properties—implication for coronary artery bypass grafting

“…Extensive data have been published on stress-strain distributions of the major vessels (Fung, 1991(Fung, , 1993Fung and Liu, 1995;Han and Fung, 1996;Huang and Yen, 1998;Fung, 1988, 1992;Lu et al, 2001;Rachev et al, 1998;Zhao et al, 2000;Zhou and Fung, 1997). It is now well documented that the vascular system expresses residual strain in the no-load state Liu and Fung, 1988Zhao et al, 2000Zhao et al, , 2002.…”

A multi‐model approach to intravenous filter optimization

“…The structure of the pulmonary network ( Figure 2) was reconstructed on the basis of reported clinical investigations [8,9]. Implementation of the systemic circulation structure ( Figure 3) is more tedious.…”