We present a model of the cardiorespiratory system that includes a 1D-0D description of the cardiovascular system, a 0D description of lung mechanics, gas transport and exchange in the systemic and pulmonary vessels, and a description of local autoregulation phenomena. Simulations are conducted on a highly detailed 1D arterial-venous network model, which is coupled to a 0D description of lung mechanics. We describe the transport of respiratory gases in the circulation treating them as passive scalars transported by blood. We simulate gas exchange in the lungs across the hemato-alveolar membrane, considering diffusion as instantaneous, and between peripheral capillaries and tissues, under the assumption that blood and tissues form a homogeneous blood-tissue compartment. Additionally, we include a description of basic autoregulation phenomena, which act on vascular resistances and compliances in response to changes in blood gas concentrations (metabolic response) and flow rate (myogenic responses). We show several examples that illustrate the predictive capabilities of the model, and investigate scenarios of interest.