Fertilization, Implantation, Infertility Flashcards
The last few slides are likely unimportant
What does the ovary produce to regulate follicular growth?
AMH
inhibin
Spermatogenesis makes sperm, which are released into _______ and collected in ____.
seminiferous tubules
testes
What are the structures involved in spermatogenesis?
sem. tubules (which anastomose to)»_space; epididymis (which collect to form one:)»_space; vas deferens
Functional units of the ovary
follicles
Eggs are derived from…
yolk sac
Females have peak # of eggs at:
7 mo. (20 wks) gestation
***SHARPLY DECLINES!!
For each egg that is ovulated, _____ apoptose
1000
Each oocyte is inside…
a follicle
When are max # of eggs lost?
while in utero
What female gamete stalls at prophase I?
primordial follicle and primary oocyte
germinal vesicle state
What occurs at the tetraploid stage in female gametes?
crossing over (genetic diversity) **this is in prophase I
(Mature/immature) oocytes do NOT have a nucleus.
mature
(Mature/immature) oocytes have a nucleus.
immature
What structure indicates an egg can be fertilized?
polar body
When does meiosis “restart” in female gametogenesis?
at ovulation (at the graafian follicle)
When is a polar body released?
first meiosis
A polar body is (haploid/diploid).
diploid
What occurs at metaphase II in female oogenesis?
stalls under fertilization
The egg accumulates _____ under its cytoplasmic membrane.
zona pelucida comprised of glycoproteins
The primary follicle is characterized by the presence of what cells?
granulosa cells, which are flat to cubic shaped
What occurs in the secondary follicle?
the egg becomes bigger with multiple layers of granulosa cells
What do granulosa cells in the 2’ follicle produce?
fluid (which accumulates in follicle)
estrogen (which feedsback to inhibit FSH)
What occurs in the 3’/graafian follicle?
fluid continues to accumulate, making the follicle larger than the others
What is the corona radiculata layer?
100s of granulosa cells which surrund oocyte
Zona pellucida is broken down/penetrated by:
the acrosomal enzymes in the sperm
What is the oolemma?
cytoplasmic membrane of ooctye
How does the egg prevent other sperm from entering?
Once a sperm has penetrated, cortical granules accumulate below the oolemma
How does the sperm enter egg?
Tail never penetrates the egg
head fuses with egg’s membrane and pro-nucleus of sperm is released inside the egg
Once fertilization has occurred, what cells/structures will be present?
2 polar bodies
2 pro-nuclei (egg/sperm)
When does mitotic replication begin?
when 2 pro-nuclei fuse and zygote formed
When does the zygote enter the 2-cell stage?
day 1
When does the zygote enter the 8-cell stage?
3rd day post fertilization
In IVF, when is the fertilized egg transferred?
8-cell stage or blastocyst (at day 5/6)
Naturally, fertilization occurs most frequently in the:
ampulla of the fallopian tube
When does the blastocyst reach the uterus? When does it implant?
day 4/5
~1-2 days after that
In what orientation does the blastocyst implant?
with the inner cell mass towards the mucosa
The inner cell mass of the blastocyst will develop into:
embryo
The outer cell mass of the blastocyst will develop into:
placenta
Makes hCG?
placenta
In females, hCG results in:
progesterone synthesis by granulosa cells
How is gestational age measured?
from date of last mentrual period
Embryonic life starts at:
conception/fertilization (couple weeks behind GA)
3 wks of embryonic life = ____ wks’ gestation
5
Normal fertilization = pregnancy occurs after ~__ months of “trying”
12
What is Fecundability?
Probability that ONE CYCLE results in pregnancy; 20-25% in normal couples
Definition of infertility:
One year of unprotected intercourse without conception
Definition of infertility if you’re >35 y/o:
Six months of unprotected intercourse without conception
What occurs as Sperm ascend through Cx, Ut, FTubes?
acquire the capacity to fertilize the oocyte (male factor)
How does the cervix play a role in fertilization?
filters and nurture sperm into Ut and Tubes (cervical factor)
How do the F Tubes play a role in fertilization?
capture ovulated oocyte and transport sperm and embryo
Causes of infertility:
___% related to male factor
___% related to female factor
40
60
(20% combined)
Among female causes of infertility, what structures are most to least likely to be responsible?
Tubal/peritoneal > Ovulatory > Cervical/uterine
What is measured in a semen analysis?
Volume Concentration motility morphology pH round cells
Evaluation of male factor infertility includes what tests/labs?
- -FSH, LH, PRL, Testosterone
- -Karyotype
- -Y chromosome microdeletions
- -Semen analysis
What are some disorders/conditions responsible for male infertility?
Retrograde ejaculation
Duct obstruction
Hypogonadism
CBAVD
T1DM is associated with what cause of infertility?
Retrograde ejaculation
Evaluation of cervical factor:
Cultures
Post-coital test
What may cause cervical factor to be cause of infertility?
Anatomical changes (DES exposure)
Infections (TB)
Changes in mucus characteristics
What may cause uterine factor to be cause of infertility?
Anatomical changes (congenital malformations, fibroids/adhesions)
Functional abnormalities (endometritis, receptivity)
Evaluation of Uterine/Endometrial factor
TV Ultrasound and Sonohysterography
Hysterosalpingography
Hysteroscopy
Endometrial biopsy
What may cause Tubal/peritoneal factor to be cause of infertility?
Anatomical changes (congenital malformations, BTL, adhesions, endometriosis)
Evaluation of tubal/peritoneal factor
Hysterosalpingography
Laparoscopy with chromopertubation
Sonohysterography
What may cause Ovarian factor to be cause of infertility?
Ovulatory dysfunction:
• Oligo/Anovulation
• Luteal phase deficiency
Evaluation of ovulatory dysfunction
Menstrual history
Basal body temperature
Serum progesterone
Urinary LH excretion (ov. predictor kits)
Basal FSH/Clomiphene challenge test
Oligo-amenorrhea testing
