Review 4.7 Flashcards
where does the PGC begin
epiblast layer
when does epiblast and hypoblast and the PGC starting begin (what week)
week 2
how long does it take for PGC to reach primtiive streak1
1 week
how does PGC get from dorsal wall of yolk sac to gonadal ridges?
hitches ride on hindgut mesentary
what is the genital ridges formed from
urogenital system
**know the chart by heart about the trilaminar disk
pg 2 & 3 of trilaminar disk lecture
a PGC what is number of chromosomes and N number
46, 2N
genital ridge is subdivision of what
subogenital ridge
once PGC is in genital ridges what is division
mitosis
why does it take roundabout pathway to get to genital ridge
everything is rapidly dividing
genital ridge isn’t there in week 2 won’t be there until week 5 or 6
primordial germ cells become what
oogonia or spermatogonia
when do we know gender
when PGC reach genital ridge
when does meiosis I start in women
5th month of intereuterine life
when does meiosis I start in males
puberty
what type of follicles does a primary oocyte have
primordial follicle
primary follicle
secondary follicle
when does primary oocyte change to secondary oocyte (what follicle)
tertiary follicle
how many of 15 -20 make to to tertiary follicle
1
genetically there’s no difference b/w what regarding female meiosis
polar body and oocyte
what is clinical correlation if part of chromsome is loss during crossing over
mutant gene
be able to talk about mutant genes
nondisjunction - describe what can happen if this happens
total # polar body at end
3
are each of spermatids equally likely to fertilize
yes
if spermatids are injected into ampulla of uterine tube what is chance for pregnancy?
0% - it hasnt undergone activation process yet
what do spermatids need to undergo in order to be able to fertilize egg
activation process
what is activation process
change in body work of spermatid
no change in genetics
identify genetial ridge
pg 4 in review
where is the caeolimic epiehtlium come from
eurogenital intermediate mesoderm
what are testis cords formed from
intermediate mesoderm
what happens to solid testis cords
they will hollow out and form seminiferous tublules
what will seminiferous tubules form
rete testis
rete testis, etc is formed from what
intermeidate mesodrm
what is epididymus formed from
mesonephric duct (which still comes from intermediate mesoderm)
what happens ot most of mesonephric duct
goes away - tiny peice formes epididymus
what does mesonephric duct come from
intermediate mesoderm
what is spermiogeneis
rounded spermatids become eloganted spermatazoa
is there any change in nuclear/genetic structure in spermiogenesis
none
what is the capacitation reaction/proces
acrosomal head is revealed
It occurs after sperm enters female genital tract
(decapitate sounds like capacitation, probably same root word)
what three things does the sperm need to go through
corona radiata
zonua pellucida
membrane of secondary oocyte itself
in female everything is formed from what
intermediate mesoderm (except PGC)
why do we need primary cords in female even though its not used
its step by step process, need to develop in order for secondary cords
what type of follicle is this?
identify - pg 7
what is difference b/w primoridal and secondary follicle genetially
nothing
what are the granular cells in secondary follicle called
cumulus oophorus
what should be there in tertiary follicel
secondary oocyte + polar body
after ovulation what will become the corpus leuteum
theca externa & theca interna
the theca + granulosa cells will become corpus leuteum
if there is no fertilization what does corpus leuteum become
corpus albicans
after fertilization occurs, as soon as male DNA is excreted into secondary oocyte, what happens
finish meisos II
form male and female pronuclei
once they fuse its now called zygote (instead of ovum)
then zygote forms two blastomeres
from blastomere stage on what is process of division
mitosis
cell# 8-16 stage what is it called
morula
what is wrapped around the blastomeres
zona pellucida
what is the process the morula undergoes
compaction
what is formed during compaction
inner call mass & outer cell mass
what is another word for inner cell mast
embryoblast
when compaction process occurs what is it called
blastocyst
is blastocystic cavity the same thing as primary yolk sac
no
primary yolk sac has what forming inner layer
hypoblast cells
blastocyst comes into body of uterus, where should implantation occur
superior posterior wall of uterus
before implantation occurs, what must be shed
zona pellucida
what is keeping endometrium developed?
estrogen and progesterone feeding back from corpus leuteum
embryoblast splits into what
epiblast and hypoblast
what is first system to develop
reproductive
what is second system to develop
cardiovascular
what developes after cardiovascular system
nervous
what part of baby is formed from hypoblast
NONE
every part of hypobalst forms what
extraembryonic structures - esp. fetal side of placenta and inner lining of primary yolk sac
the mature or developing trophoblast divides into what
inner cytotrphoblast & outer synctiophroblast
what is process that causes hypobalst cells to go down laterally
arrival of definitive endoderm
identify primary and secondary yolk sac
pg 10
inner lining of secondary yolk sac is what
hypoblast cells
hypoblast cells form what in yolk sac
extraembryonic mesoderm
hypoblast cell form what lining outside of yolk sac
visceral extraembryonic mesoderm
identify parietal and visceral embryonic mesoderm
pg 10 of review
or pg 9 of 2nd 3rd week
what forms connecting stalk
1/2 from pareital extraembryoinc mesoderm
1/2 from visceral extramebyonic mesoderm
what is this cavity (shown by moon ) pg 10
chorionic cavity
in week 3 what 3 major things happen
- appearance of definitive primitive streak in epiblast layer
- development of notocord
- differentiation of three germ layers (gastrulation)
what is it called when three germ layers differentiate
gastrulation
where does notochord come from
mesoderm cells
fetal side only of placenta is formed form what three layers
- parietal extramebryonic mesoderm
- cytrotrophoblast
- syncytiotrphoblast
what happens when hole are poked into synctiotrophoblast
lacunae
as hole are put - lacunae what happens
blood flows in and allows circulation
what is difference b/w primary, secondary, tertiary villi**
- Primary villi- STB and CTB
- Secondary villi- STB, CTB, Parietal extraembryonic mesoderm (PEEM)
-Tertiary villi- STB, CTB, PEEM, capillaries in PEEM,
capillary lining forming placental membrane
which villi is most priminent at end of pregnancy
tertiary villi
where do all 3 layers (endoerm, ectoderm, mesoderm) come from
epiblast
what does endoderm do to hypoblast
pushes hypoblast cells to yolk sac
mesoderm cells flow like water how
from back to front
what don’t move from the 3 layers of epiblast
ectoderm
what is this area going to become? pg 15 blue circle
gut tube
head fold starts to bend and helps to divdie what
cephalic flexure
what does tail fold help do
helps form cervical flexure
what else does tail fold regarding allantois
forces allantois into connecting stalk
if if the vitellointestinal stalk is not pinched off right what is the pathology
meckels’ diverticulum
entire body cavity is formed b/w primitive space b/w what two things
visceral and pareital laterl plate mesoderm
what process enlarges the primitive body cavities
lateral folding
what does lateral folding help do
form midgut
what is this pg 17
notocord
normally lateral fold will do what in ventral surface
fuse
heart and lungs are asc. or desc.
descending
as heart and lungs descend what are they doing
pushing septum transversum down
as septum transversum being pushed down what happens
lungs burwo through pericardial pleural canal
what will it form when the lungs are pushing through the pericardial canal (septum transversum)
form visceral pleura
as heart goes from back to front it will peel off peice of mesentary
pleural pericardial folds
pleural pericardial folds fuse together to form what
fibrous and parietal pericardium
in the pericardial folds are what two things
- phrenic nerve
2. common cardinal vein
what is innervation of pericardium
phrenic nerve
what does common cardinal vein form
SVC
identify septum transversum
pg 19
fibrous and muscular part of diaphraghm are connected, where do they originate? what pathology could occur?
two different sources
congenital diaphragmatic hernias are common
gauge marks (from lungs making visceral pleura) are filled in with what
myoblasts
pleural peritoneal membrane is from what
perital lateral plate emesoderm
septum transversum is from what
VLPM
myoblasts are from what
pariaxial mesoderm
anytime the fibrous and muscular part of diaphragm don’t join, what happens?
diaphgramatic hernia
is mouth embryolgically part of GI system
no
why isn’t mouth part of GI system embryoligcally
it’s not endoerm inside
VLPM outside
what is mouth made of
skeletal msucles (paraxial mesoderm)
pharyngeal arch 1 comes in and what does pharyngeal arch 2 does what
migrates
all the pahryngeal arches have what come into them
all the arteries and veins - they go to pharyngeal arches before going to their targets
bucoorynpharingeal membrane is what
physical separation from GI tract from the mouth
eventually bucopharyngeal membrane will do what
rupture - allowing amniotic fludi to flow through
what is pink pg 21
endoerm
gut wall is what
VLPM
if there is a bud off GI tract it is what
enderm inside
VLPM outside
name exmple of organs budding off GI tract
lungs pancreas bladder liver urethra of male male & female GI tract
what happens if there is improper esophageal recanalization?
esophageal atresia
what is esophageal atrea example of regarindg congenital abnormalities
disruption
what is the major mover of the foregut
dorsal or back of stomach divides faster than front, it goes in clockwise rotation
how does stomach turn
clockwise 90 degrees
what is only part of ventral mesentary left over
falciform triangular ligaments
lesser omentum
is spleen part of GI tract embryoligically
No
BUT it is moved by foregut
is spleen moved with foregut
yes
everything in GI tract it:
endoderm inside
VLPM outside
suprarenal glands are from GI tract?
No
due to development of what major structure that forces midgut out
gonads - urinary system
what will be affected by midgut and rotation of midgut loop?**
only midgut
will first part of duodenum be affected by gonad/urinary development pushing stuff out
no
will descending colon be affected by gonad/urinary developiment pushing stuff out
no
what does cloacal membrane form at end of hindgut
dentate/pectinate line
what does dentat/pectinate line mean
end of hindgut, beginning of proctoderm
above pectonate line innervation is
autonomic
below pectonate line innervation is
pudenal
identify stuff on pg 27
pg 27
what are two most important structures coming from urogenital sinus
bladder
urethra
What is the Acrosome reaction/process
When sperm binds to zona pellucida of secondary oocyte - allows it to digest through zona pellucida & sperm nucleus enters the cytoplasm
why do mesoderm cells start in the back?
that is where primitive streak is
what are two most important things head fold forms/does?
shifts heart from dorsal to ventral
takes a little piece that will form foregut
What will the vessels of allantosis form?
umbilical vessels
Pg 15 of review, red circle
What is the pathology that occurs here if the vitellointestinal stalk is not pinched off correctly
meckels’ diverticulum
What is a superior section defect of ventral lateral folding?
ectopia cordis
What is ectopia cordis?
ventral body wall defect
heart lies outside body
What are two middle section defect of ventral wall & lateral folding?
Gastroschisis
Omphalocele
What is Omphalocele?
ventral body wall defect
Herniation of the abdominal viscera through an enlarged umbilical ring
What is Gastroschisis?
body wall closure failure in abdominal region with intestines in amniotic cavity
Describe an inferior section defect of ventral wall lateral folding defects
Abnormal body wall closure in pelvic to rectum regions
If there is combined superior, middle, & inferior section defect of ventral body defects from lateral folding, what is it called?
cantrell pentology
What happens if there is defective tracheoesophageal septum?
esophageal atresia
What happens if there is non vascularization of esophagus?
esophageal atresia
describe what happens in esophageal atresia
esophagus ends as a bind sac in 8th week
