Fertilization Flashcards
sperm viable for
3-5 days after ejaculation
egg viable for
24 hours after ovulation
where does fertilization usually occur?
ampulla of oviducts
corona radiata
follicle cells surrounding the egg
what happens to membrane once sperm has entered egg?
changes to prevent more sperm from entering
what happens to zygote once formed?
- travels to uterus (takes 3-4 days)
- while traveling, undergoes frequent mitosis to become morula
morula
what zygote rapidly divides into as travels to uterus
what happens to morula once arrives in uterus?
- stays unattached for 3-4 days
- divides to become blastocyst while endometrium prepares for attachment
blastocyst
- formed from morula once it reaches uterus (before attaching)
- secretes HCG
HCG
- human chorionic gonadotropin
- what look for in a urine pregnancy test
- stimulates corpus luteum to release progesterone
effect of progesterone on endometrium
- increased blood supply
- secretes glycogen to sustain blastocyst
implantation occurs how long after fertilization?
~7 days
what happens to blastocyst after implantation?
- some of its cells form 3 layers that become embryo
- rest of cells become supportive cells for embryonic function –> form supportive structures