Cell shapes

A few general issues concerning the shape of cells, their visualization, spatial considerations, and resolution, need to be examined prior to discussing the use of Fourier analysis. This may somewhat complicate matters, but will allow a better focus on the quantitative evaluation of cell shapes, as well as the suitability and applicability of the proposed methods.

Basic cell shapes

Cell shapes may be divided into four main categories. The first applies to the vast majority of cells, and includes forms with convex or concave surfaces as well as short cytoplasmic extensions of the type found in epithelial, connective tissue, and smooth and cardiac muscle cells (Figures 13.1a–b, 13.1f–k). The second category includes giant structures, known as syncytia, produced by the fusion of several cells. An example of the latter is the long cylinders of skeletal muscle fibers (Figure 13.1c). The third category includes cells with branching processes, which form extended networks. The shape of these latter cells corresponds more to a logic graph (dendrogram or tree structure) than to a simple surface. Nerve cells belong to this group (Figure 13.1d). The fourth category is made up of those forms that differ topologically from the previous ones.