This paper provides a summary of our recent work on the scaling relations between the specific angular momentum j _ { \star } and mass M _ { \star } of the stellar parts of normal galaxies of different bulge fraction \beta _ { \star } .
We find that the observations are consistent with a simple model based on a linear superposition of disks and bulges that follow separate scaling relations of the form j _ { \star { d } } \propto M _ { \star { d } } ^ { \alpha } and j _ { \star { b } } \propto M _ { \star { b } } ^ { \alpha } with \alpha = 0.67 \pm 0.07 but offset from each other by a factor of 8 \pm 2 over the mass range 8.9 \leq \log ( M _ { \star } / M _ { \odot } ) \leq 11.8 .
This model correctly predicts that galaxies follow a curved 2D surface in the 3D space of \log j _ { \star } , \log M _ { \star } , and \beta _ { \star } .