Practice question

Hyperactivation is vigorous, high-amplitude asymmetric flagellar beating pattern required for penetrating cumulus matrix and zona pellucida. Transition from progressive motility depends on massive calcium influx through sperm-specific CatSper complex located in principal piece of flagellum. Progesterone from cumulus and intracellular alkalinization during capacitation activate CatSper, raising flagellar calcium, stimulating calmodulin kinases and altering dynein motor regulation. Resultant whip-like thrust generates increased force, and pharmacologic CatSper blockade prevents hyperactivation demonstrating absolute channel dependence for fertilization competence and ascending oviductal transport mechanisms.