A numerical anthropomorphic model of the breathing thorax and the beating heart is presented. It includes the main thoracic/cardiac anatomical structures, the main vessel junctions as well as the structures' motion. Its main feature is that it is based on a Magnetic Resonance Imaging (MRI) examination performed on the same human subject within the same session from which both structural and motion information are retrieved. This confers to the model a very good consistency. This numerical model is virtually imaged by two simulators: a MRI simulator and a Positron Emission Tomography (PET) simulator. The overall resulting model (structure geometry & dynamics, images) is useful for the evaluation of cardiac image processing algorithms such as heart structure segmentation or multi-modality cardiac image registration.