A mathematical model for pulmonary blood circulation

Human pulmonary circulation is studied by using a quasi-one-dimensional unsteady nonlinear fluid model. It is applied to 17 generations of blood vessels composed of the branching arterial, capillary, and venous distensible vessel segments which make up the complete pulmonary circulation. An idealized pressure-area relation is introduced describing the varying degrees of vessel collapse. The model gives satisfactory agreement with the experimental data: a dramatic pressure drop occurs in the arterioles and postcapillaries, and a negative transmural pressure is shown in the postcapillary and small venous segments. This model can also be used to study abnormal pulmonary circulation, such as arteriosclerosis, atherosclerosis, vasospasm, hypertension, etc