The aim of this work was to develop a lumped parameter model of the cardiovascular system and to couple it with a model of respiratory mechanics. In comparison to existing models, modifications and additions have been implemented to include a model of the upper limb vasculature employing the electrical analogy of hemodynamic variables. The model prediction of respiratory effects on arterial pressure was compared with in vivo invasive measurement of blood pressure in patients. The model indicates that the inherent coupling between the cardiovascular and respiratory systems can be described by mathematical relationships of physiological parameters with robust predictions. With specification of parameters based on individual measurements of cardio-respiratory variables, the model can be used in the clinical setting of intensive care units to predict hemodynamic changes and to optimize ventilation and volume loading strategies.