Biomechanics of the cardiovascular system: the aorta as an illustratory example

Abstract

Biomechanics relates the function of a physiological system to its structure. The objective of biomechanics is to deduce the function of a system from its geometry, material properties and boundary conditions based on the balance laws of mechanics (e.g. conservation of mass, momentum and energy). In the present review, we shall outline the general approach of biomechanics. As this is an enormously broad field, we shall consider a detailed biomechanical analysis of the aorta as an illustration. Specifically, we will consider the geometry and material properties of the aorta in conjunction with appropriate boundary conditions to formulate and solve several well-posed boundary value problems. Among other issues, we shall consider the effect of longitudinal pre-stretch and surrounding tissue on the mechanical status of the vessel wall. The solutions of the boundary value problems predict the presence of mechanical homeostasis in the vessel wall. The implications of mechanical homeostasis on growth, remodelling and postnatal development of the aorta are considered.

Age estimation based on a combined arteriosclerotic index

“…It is also not clear whether the area ratio depends linearly on age since the prestrain, which is a dimensionless deformation measure, depends nonlinearly on age [22,23]. Finally, it should be noted that this was a somewhat simplified interpretation, since the cylindrical geometry of an artery is also prestrained in the circumferential direction (this strain is usually called "residual" and is manifested when a radial cut of an arterial ring is made as an abrupt opening to a sector [30,31]). We therefore prefer to use CAI, although its biomechanical interpretation is not as straightforward as in case of the area ratio.…”

Mechanical behavior of human aortas: Experiments, material constants and 3-D finite element modeling including residual stress

“…Although the mechanical properties of the aorta have received considerable attention (see recent review in Kassab, 2006), most studies have dealt with animal species only. Thus, testing of fresh human aortas is needed, and the accuracy of constitutive models and finite element simulations must be ascertained.…”

Effect of Tulbaghia violacea on the blood pressure and heart rate in male spontaneously hypertensive Wistar rats

“…Blood serves as the vehicle for delivery and removal of nutrients and waste products respectively, while the vessels serve as the highways. These 'highways' have a passive capacitance function that maintains the BP in diastole, and an active auto-regulatory control that allows the organ to respond to local metabolic demands (Kassab, 2006).…”