Fields: Fertilization Flashcards
primordial germ cells undergo _____ during the weeks 4-5 and are now called oogonia
mitosis
when does mitosis cease for all oogonia
5th month
when does meiosis begin for all oogonia
5th month
when oogonia go through meiosis I what do they become
primary oocytes
what happens at birth for primary oocytes
they stop at prophase I of meiosis I
at puberty (age 12-13), what happens
meiosis I resumes and completes and meiosis II begins
what forms when meiosis II begins after puberty
secondary oocytes
23 pairs of homologous chromosomes are present in each cell
diploid
There are 2 sister chromatids/homologous chromosome or 2 x 23 = 46 chromatids
2n
1 of each pair of homologous chromosomes in each cell
1n (haploid)
when do breast buds start to form and also pubic hair
age 9-11
when does acne first appear; armpit hair; increase in height at fastest rate
after age 12
first period arrives; puberty begins (meiosis II begins)
around age 8-13
number of eggs will decrease from 7-10 million to ovulate only ____ throughout an individuals lifetime
400
when does mitosis of spermatogonia start
at puberty (9-14 yrs)
Type A or Type B is used for spermatogonia
Type B
after mitosis, what do spermatogonia become
primary spermatocytes
what do primary spermatocytes undergo to become secondary spermatocytes
meiosis I and II
_____ undergo differentiation and become active sperm (spermatozoa)
spermatids
males produce_____throughout lifetime
sperm
after meiosis II in spermatogenesis, what do you get
4 spermatids (4 cells)
after meiosis II in females, what do you get
1 egg (1 cell), with 3 polar bodies
haploid egg + haploid sperm=
diploid cell (zygote)
spermiogenesis
spermatid to spermatozoan (sperm)
where do spermatogenesis and spermiogenesis occur
seminiferous tubules
compartment adjacent to basement membrane
basal compartment
compartment adjacent to the lumen
Adluminal compartment
prevents harmful blood borne agents from reaching the developing spermatogonia
blood testis barrier
____ junctions b/t sertoli cells create blood testis barrier
tight junctions
nondisjunction causing 47 XXY
gynecomastia
small testes
low testosterone
sterile
Klinefelter’s syndrome
nondisjunction causing 47 XYY
low weight and taller than normal
delayed puberty
acne
lower IQ
Jacob’s syndrome
nondisjunction involving 45 XO
small stature
sterile
web neck
Turner’s syndrome
Flattened granulosa cells that surround primordial germ cells
Primordial follicle
Cuboid cells.
They secretes estrogen
Primary follicle
Acellular membrane secreted by follicle c
membrane granulosa
Acellular membrane between the egg and follicle cells. Formed from secretory. products of the egg and follicle cell.
Zona Pellucida
Cells adjacent to the membrane granulosa.
Derived from differentiation of fibroblast.
They secret testosterone.
Theca cells
primordial, primary, growing, antral follicle with what stage of oocyte development
primary oocyte
mature/Graffian follicle with what stage of oocyte development
secondary oocyte
Once the population of eggs becomes very low, the woman enters ____
menopause
egg breaks through what two layers to be released from Graffian follicle into peritoneal cavity
stigma and mesovarium
postovulatory follicle becomes what
corpus hemorrhagicum
theca and granulosa cells mix and become ____ and secrete progesterone
corpus luteum
Mittelschmerz
lower abd pain associated with ovulation, and occurs midway through menstrual cycle
what does corpus luteum become if fertilization doesnt occur
corpus albicans
where does fertilization occur in females
ampulla of fallopian (uterine) tube
occurs in female reproductive tract; membrane proteins will be shed from the sperm and head of sperm (acrosome) exposed
capacitation
egg is ovulated where
peritoneal cavity
what picks up ovulated egg
fimbriae
occurs when sperm comes in contact with follicle cells of the corona radiate in the ampulla of the uterine tube.
When contact is made with follicular cells, the acrosomal cap disintegrates exposing surface protein on the acrosome membrane
acrosome reaction
sperm surface proteins bind to receptors on ______ of egg
zona pellucida
Scaring of uterine tube from ____ can prevent transport of egg and sperm
STDs
The sperm penetrates the corona radiate and comes in contact with the egg membrane. This creates an electrical gradient that knocks other sperm off
fast block
cortical granules (blue box) are released into the perivitelline space (PVS) between the zona pellucida (ZP) and the egg membrane. Fluid follows the granules into this space, and enlarging the space. Makes it harder for the sperm to reach the egg.
cortical reaction
Hardening of the zona pellucida
zona reaction
why are there 3 ways to prevent polyspermy
to prevent molar pregnancies
2 types of molar pregnancies
partial and complete
why is it important that all placental tissue is removed after birth
to prevent choriocarcinoma
Genome abnormality that yields
> 2 multiples of haploid chromosomes
polyploidy
69 chromosomes
triploid
spotty bleeding (grape like vesicles)
elevated hCG
embryo
cystic placenta
partial molar pregnancy
produced by non-disjunction of a single chromosome and not the total genome
trisomy (aneuploidy)
spotty bleeding
elevated hCG
cystic placenta
no embryo
complete molar pregnancy (diploid 2n)
complete molar pregnancy
metastatic choriocarcinoma
fertilized egg aka
zygote
genomes of sperm and egg will come together and form what
zygote
You can take 16 cell out and it will develop into individual (what is that called)
morula
inner cell mass will become
embryo
trophoblast will become
placenta
Secreted by the blastomeres 24-48 hours
post - fertilization
EPF (early pregnancy factor)
blastocele cavity will become
chorionic cavity
inner cell mass into what 2 things that form bilaminar disc
epiblast and hypoblast
are invasive, penetrate the uterine epithelium & implant in the
uterine endometrium
trophoblast cells
differentiate into cytotrophoblast cells
trophoblast
cytotrophoblast fuse and form multicellular ______ cells
syncytiotrophoblast cells
what secrete hCG in placenta
syncytiotrophoblast
____ pregnancies most commonly occur in ampulla of uterine (fallopian) tube
ectopic
can occur in the Peritoneal Cavity, Peritoneum or Rectouterine Pouch/Pouch of Douglas. 96% occur in the uterine tube
ectopic pregnancies
Syncytiotrophoblast stimulate formation of _______cells in the endometrium
decidual
are differentiated fibroblast cells. They secrete prolactin that initiates development of the mammary glands & milk production
Decidual cells
creates an immunologically privileged site for the embryo in the uterus
decidua
_____ implanted can be considered foreign body b/c male component is in it
zygote
2 zones of endometrium
functional
basal
this zone of endometrium contains majority of glands and is sloughed off during menstruation
functional zone
layer of endometrium just under myometrium; smooth muscle of uterus
basal zone
region of decidua at base of implanting embryo
decidua basalis
region of decidua that is the site where endometrium closes after complete implantation
decidua capsularis
region of decidua that contains remaining areas of endometrium including the opposite wall of uterine lumen; this is only at implantation site
decidua parietalis
chorionic cavity develops in the
reticulum
epiblast from inner cell mass will become
embryo
hypoblast from inner cell mass will become
other cells
amniotic cavity forms when fluid collects where
in the epiblast
cells from ____ line the inner surface of the cytotrophoblast
hypoblast
Cells from the hypoblast line the inner surface of the cytotrophoblast.
This creates the
primary yolk sac/ Heuser’s membrane
___ is secreted by the hypoblast
reticulum
___ form in the reticulum
lacunae
____ coalesce to form the chorionic cavity
lacunae
_____mesoderm from the epiblast lines the chorionic cavity
extraembryonic
The bi-laminar disc is suspended by the _______of extraembryonic mesoderm
connecting stalk
Site of germ cell formation and erythropoesis
definitive yolk sac
Primary yolk sac (Heuser’s membrane).
Reticulum.
Chorionic cavity.
Definitive yolk sac (site of germ cell formation
(from what)
hypoblast
Extraembryonic mesoderm lining the chorionic cavity.
Extraembryonic mesoderm forms the connecting stalk.
Amniotic cavity.
(from what)
epiblast
How many cell layers do blood products from the mother have to diffuse across in order to reach the fetal circulation?
4
detecting ____ in blood stream of mother beginning 10 days after fertilization
hCG
1st week primary villi form and only what is present
syncytiotrophoblast
in the 2nd week, secondary villi form and what is present
syncytiotrophoblast, cytotrophoblast and extraembryonic mesoderm
week _____: have area where you can exchange nutrients now products have to cross all the layers ”-blasts”
week 3
form in yolk sac and give rise to celiac trunk, superior and inferior mesenteric a.
vitelline blood vessels
Remnant of ______ may remain as diverticulum off ileum (Meckel’s diverticulum) acts like an appendix
yolk sac
stimulates formation of umbilical blood vessels
Allantois
Allantois degenerates and becomes ___
urachus
connecting stalk contains what
allantois w/ fetal vessels around
yolk sac surrounded by vitelline vessels
As pregnancy proceeds, cytotrophoblast will essentially drop off, so how many layers do blood products have to diffuse across at this point
3
PSEUDOCOTYLEDON (the cotyledons are not completely separated by a septum
normal discoid human placenta
side with umbilical cord
fetal side of placenta
blockage of the internal os of the cervix
placenta previa
chorionic villi growth deep in the endometrium
placenta accrete
chorionic villi growth into the myometrium
placenta increta
chorionic villi growth beyond the myometrium, into the broad ligament of the uterus, peritoneum of the bladder, detrusor muscle of the bladder
placenta percreta
2 types of chorion
villous
smooth
Villous Chorion
smooth chorion
with fetal expansion, what fuse
amniotic membrane and chorionic membrane with decidua capsularis
work horse of placenta; secreting hormones and steroids
syncytiotrophoblast
2
amniotic cavity develops where
in the inner cell mass
monozygotic twins with how many placenta, amniotic sac, chorionic sac
2, 2, 2
Developing fetuses that implant too close together; they will be sharing a lot of maternal blood; some will get all the blood, some will not (intrauterine growth retardation)
twin to twin transfusion syndrome
monozygotic twins
zygote isnt splitting completely here, but inner cell mass is so how many placenta and chorionic sacs and amniotic sacs
1 placenta
2 amniotic sacs
1 chorionic sac
how many placenta, amniotic sac, chorionic sac
1, 1, 1 (monozygotic twins)
parasitic twins
2 eggs that have been ovulated and fertilized; each have their own placenta, own chorionic sac, own amniotic sac implant close together; placentas can fuse and end up with twin to twin transfusion syndrome
dizygotic twins
89% of women are Rh ____
Rh +
If mother is ____ and fetus is Rh +; mother will develop antibodies against red blood cells that are in fetus and end up with Erythroblastosis Fetalis
Rh-
transfuse Rh- blood to fetus or administer anti-Rh antibodies to Rh- mother after birth of each Rh+ baby; will prevent mother from producing antibodies to fetal blood in next pregnancy
prevention of erythroblastosis fetalis
lack of fluid in sac causing fetus to experience contractions of uterus
oligohydramnios
club feet in kids can be a consequence of
oligohydramnios
genetic testing with low levels of AFP means
trisomy
genetic testing with high levels of AFP means
liver or germ cell tumor; neural tube defect
happens when fibrous amniotic band constricts limb
amniotic band syndrome
