The advent of high-speed real-time (RT) MRI permits monitoring of physiological function at unprecedented frame-rates. Here, physiological dynamics at 25-100 frames-per-second are explored using temporal domain Fourier transform (FT) and principal component analysis (PCA). RT cerebral, cardiac and pharyngeal datasets are acquired with continuous radial encoding and nonlinear inverse reconstruction implemented in graphics processing units. FT detects spectral patterns in pharyngeal images acquired during speaking. FT and PCA reflect components associated with breathing and cardiac functions in the brain while decomposition and synthesis in the time-domain can pinpoint cardiac wall motion abnormalities in patients with heart disease.