Fig 2. Three layers model of the arterial wall.

(a) The unstressed reference state of a multi-layer annulus defined by A<R<D. (b) A pressurized artery with no intimal growth at time t=0. The intima is healthy and its thickness, usually on the order of 5-10 μm, is exaggerated for clarity. (c) A grown, pressurized artery at time t>0; the annulus is now defined by a<r<d. The lumen pressure is P and the intima is significantly thicker than in (b). The radial coordinate in the reference frame is denoted R and it ranges from A (radius of lumen) to D (radius of the boundary of the adventitia). The lower case letters denote positions in the deformed frame; thus r is the radial coordinate in the deformed frame and it ranges from a (radius of deformed lumen) to d (radius of the boundary of the deformed adventitia).