MedicineEndocrinologyPhysiologyReproductive BiologyReproductive EndocrinologyReproductive PhysiologyEndocrine Regulation Of ReproductionFollicular DynamicsGonadal HormonesHypothalamic-pituitary-gonadal AxisPituitary Gland FunctionPituitary HormonesDominant Follicle DevelopmentFollicle AtresiaFollicular Development RegulationFollicular Growth DynamicsFollicular StructureGonadotropin RegulationOvarian Follicle DynamicsPreovulatory Follicle Development
During folliculogenesis a group of growing preantral follicles becomes responsive and dependent upon gonadotrophins, especially FSH, for their continued growth and differentiation. However, most of these follicles undergo atresia. The mechanisms that result in survival of a specific number of ovulatory (dominant) follicles appear to depend upon: (a) responsiveness of preantral follicles to gonadotrophins, (b) inhibitory and stimulatory factors from a dominant follicle, and (c) an exquisitely sensitive long-loop feedback system between the dominant follicle and pituitary gland.