Fig. 1.

Schematic representation of proposed hypothesis for mechanical regulation of ovarian function and disease. a Immature follicles reside in the cortex in the human ovary. Unknown signals stimulate immature primordial follicle activation to enter the growing follicle pool. We hypothesize that the biomechanics of the ovarian environment contribute to primordial follicle activation and that the relatively dense cortex maintains follicle quiescence while the perimedullar region represents an environment more permissive to growth. b The follicles found in a PCOS ovary are usually small, accumulate in the cortex, and secrete high levels of androgen and relatively low levels of estrogen. The underlying etiology of this disease is unknown. Based on our work, we hypothesize that the relatively dense cortex creates a biomechanically non-permissive environment and is one of the contributing factors in the disease. c If this hypothesis is correct, one would predict that premature loss of ovarian function would be associated with a physically less rigid ovarian cortex