Predictions for ciliary beat frequency modulation. (A) The comparison of experimental data and model predictions for the CBF dependence on Ca2+ concentrations. The experimental data for CBF  is shown as circles whereas the model prediction is represented as continuous blue line . (B) GC activity depends on a number of intracellular mediators. The model describes the correlation of the right "peak" with the GC activity levels. (C) The model predicts that extracellular signals via G-protein pathway can significantly modulate the left "peak" of the plot of CBF dependence on Ca2+ concentration. In both cases (B and C) the diminishing amplitude is shown as green and red lines. The model describes the distinct contribution of both internal and external signals to CBF modulation.