We present a model of the cardiorespiratory system that includes a 1D-0D description of the cardiovascular system, a 0D description of lung mechanics, a 1D-0D description of gas transport and exchange in the systemic and pulmonary vessels, and a description of short timescale regulatory mechanisms. Simulations are performed on two 1D arterial-venous network models characterized by different degrees of anatomical detail, calibrated to ensure comparable cardiac output, mean arterial pressure, and flow rates in selected arteries and veins. Respiratory gases are treated as passive scalars transported by blood. Gas exchange is simulated both at the level of the lungs and between the peripheral capillaries and tissues. Additionally, we include a description of local autoregulation phenomena, baroreflex, and peripheral and central chemoreflex mechanisms [3], which act on cardiovascular function and ventilation in response to acute perturbations in arterial and venous pressures and blood gas composition. We discuss model calibration, show that our model is able to reproduce cardiovascular and respiratory physiological data under normal, hypercapnic, and hypoxic conditions, and analyse the impact of each control mechanism on the response to these conditions.