Numerical density of convex, nonbranching organelles in anisotropically oriented cells. Cilia in tangential chondrocytes.

A stereological expression relating the mean number of organelle profiles per cell profile, Np, to the mean number of organelles per cell, Nc, is first derived and then tested for cilia in tangenital articular chondrocytes where Nc is known to be 1.0. Nc derived stereologically for this organelle-cell model is 1.19. This close approximation of the estimate to a known value provides empirical evidence of the usefulness of the derived stereological expression.