//follicular Recruitment, Selection, and Dominance

The term “recruitment” has been used to describe the process by which the follicle departs from the resting pool to initiate growth. However, some authors also use this term to describe the engagement of a cohort of antral follicles into further growth. To avoid confusion, McGee and Hsueh suggested that the first situation be called initial recruitment and the latter, cyclic recruitment.[133] Cyclic recruitment, although obligatory, does not guarantee ovulation because growing follicles are vulnerable to atresia and thus may fall out from the growth trajectory. Selection refers to the process by which the maturing follicular cohort is reduced to a number appropriate for the species-specific ovulatory quota. This process entails negative selection against the subordinate follicles as well as positive selection of the follicles that will determine dominance. Although traditional thinking argues for a single wave of follicular development during the menstrual cycle, recent ultrasound studies suggest that multiple waves of follicular development occur.[134]