13.9 Fertilization and Cleavage Flashcards
What is the corona radiata?
protective layer of granulosa cells surrounding the secondary oocyte
What two components surround the secondary oocyte?
corona radiata
zona pellucida
What is sperm capacitation?
dilution of inhibitory substances present in the semen
When does sperm capacitation occur?
when sperm are deposited by the cervix during intercourse
What is fertilization?
fusion of spermatozoan with secondary oocyte
Where does fertilization normally occur?
uterine tube
What is the purpose of the acrosome reaction?
allows the sperm to penetrate the corona radiate and then bind to and penetrate the zona pellucida
What is the acrosome?
large vesicle on the sperm head containing hydrolytic enzymes which are released by exocytosis
What occurs once the sperm and egg fuse?
sperm nucleus enters the secondary oocyte causing the secondary oocyte to undergo and complete meiosis II
What forms once secondary oocyte completes meiosis II?
ootid and second polar body
What is an ovum?
mature ootid
When does a zygote form?
when the sperm and egg nuclei fuse together
What is polyspermy?
penetration of an egg by more than one sperm
What normally prevents polyspermy from occuring?
fast block and slow block
What is fast block to polyspermy?
depolarization of the egg plasma membrane preventing other sperm from fusing with the cell membrane