Early Development 2 Flashcards
Describe anatomy of sperm
Head, midpiece, tail. acrosome, mito, microtubules.
Steps of maturation for a sperm:
grow in the seminiferous tubules, then get stored in the epididymis. The epididymis matures them a bit, then they respond to female repro tract and mature even further (CAPACITATION). Fertilization competence and sperm hypermotility are acchieved.
The acrosome reaction- factors that trigger it?
The alkaline environent, signals from oocyte.
What does the acrosome reaction involve from the sperm?
Hyaluronidase, used to digest the corona radiata. also, other enzymes used to digest the zona pellucida. after which polyspermy is blocked.
when does meiosis 2 complete for the oocyte?
upon fertilization
fertilization age vs gestational age
fertilization age is generally 2 weeks younger than gestational age, because gestational age is calculated based on the LMP, so theres probably around 2 weeks before fertilization???
embryo vs zygote
a zygote turns into an embryo eventually.
assisted sexual reproduction technologies
IVF and intracytoplasmic nuclear sperm injection.
the 6 steps from ovulation to implantation and general time frame
- ovulation.
- fertilization: 12-24hours
- cleavage: 30 hours
- morula
- blastocyst
- late blastocyst: 4-5 days
trophoblast differentiates into
syncytial trophoblast (dissolves endometrial layer, secretes hCG, dissolves endometrial blood vessel walls and makes lacunae) and cytotrophoblast
early blastocyst and compaction
the morula turns into the early blastocyst after comapction occurs.
protamine histone exchange
this is how the sperm shares its DNA
how does the late blastocyst “hatch”?
the early blastocyst digests the zona pelucida.
day 6 vs day 7.5 of implantation
day 6, syncytiotrophoblast has invaded the uterine epithelium, and by day 7.5 it has invaded the stroma and the epiblast and hypoblast and amniotic cavity have formed.
Ectopic pregnancy
Basically anywhere that isnt the right spot in the uterus!
