Figure 5

Simplified illustrations of a ₃ ( r )with respect to the local coordinates axis given by \{\hat{\mathit{n}}\left(r\right),{\hat{\mathit{t}}}_{\mathbf{1}}\left(r\right) , {\hat{\mathit{t}}}_{\mathbf{2}}\left(r\right)\} . The blue plane contains the vectors \hat{\mathit{n}}\left(\mathit{r}\right), \hat{\mathit{k}}\left(\mathit{r}\right), and {\hat{\mathit{t}}}_1\left(\mathit{r}\right), and it is perpendicular to the gray plane formed by vectors {\hat{\mathit{t}}}_1\left(\mathit{r}\right), {\hat{\mathit{t}}}_1\left(\mathit{r}\right) and a ₃(r). The orange plane is the cross section of the uterus perpendicular to the vector {\left.\frac{d{\mathit{r}}_C\left(t\right)}{\mathit{\text{dt}}}\right|}_{t_0}. The gray curve is the curve of symmetry r _C (t)with r _C (t ₁)and r _C (t ₂)extreme points of the curve.