First Trimester Normal Flashcards
pregnancy is dated from the ___ day of the _____
first
LMP
____ weeks completed gestation
_____ days
_____ trimesters
40
280
3
1st trimester:
2nd:
3rd:
0-12 6/7
13-27 6/7
28-40
called an embryo from conception up to _____
10 completed weeks of LMP
after 10 weeks LMP the emrbyo is called a ___
fetus
CRL
crown rump length
how do you confirm viability
fetal heart beat with M-mode
DNA (what, constituent of, contains)
a double-stranded nucleic acid that is a constituent of chromosomes
contains hereditary info coded in specific sequences
chromosome
a threadlike nucleoprotein structure within the nucleus of a cell that contains DNA
gene
the arrangement of DNA is a chromosome
hereditary unit that carries hereditary traits for self reproducing
a double-stranded nucleic acid that is a constituent of chromosomes
contains hereditary info coded in specific sequences
DNA
a threadlike nucleoprotein structure within the nucleus of a cell that contains DNA
chromosome
the arrangement of DNA is a chromosome
hereditary unit that carries hereditary traits for self reproducing
gene
karyotype
chromosome set of an individual
described by the number and structure of chromosomes
a representation of chromosomes set in a diagram
diploid
paired chromosomes
organism with 46 chromosomes = 23 pairs
haploid
a single set of unpaired chromosomes (23)
a cell with 46 chromosomes divides into 2 new cells each with 23 chromosomes
a cell with 46 chromosomes divides into 2 new cells each with 23 chromosomes in a process called
meiosis
gametogenesis
the process of formation and development of specialized generative cells or gametes
sperm and ovum are highly specialized ___ cells
sex
sperm maturation is called
spermatogenesis
ovum maturation is called
oogenesis
mitosis
process of nuclear division where cellular material is equally divided between both daughter cells – forming new cells
all cells are formed through ___, except gamete cells which are formed through ____
mitosis
meiosis
meiosis
the process that reduces the number of chromosomes in gametes to half (haploid)
ovulation occurs at day ___ in a typical cycle
14
what must happen for ovulation to occur
LH surge
where does ovum usually get fertilized
ampullar portion of the fallopian tube
ovum lives for _____ hours if unfertilized
12-24
how many sperm are deposited on or near the cervix during intercourse
vs
how many reach the ovum
200-500 million
300-500
how long to sperm survive for
usually 24 hours (but can be up to 72)
what is a normal count of sperm per ml
100 million sperm/ml
how many sperm per ml is considered to be sterile
≤20 million/ml
process of fertilization normally takes place ____ after ovulation
12-24 hours
____ autosome(s) from each sperm/egg, ___ chromosome(s) from each sperm/egg
22
1
in fertilization, the sperm passes through the _____
zona pellucida
what is the purpose of the zona pellucida
ensure only one sperm can enter
helps with implantation
what is the purpose of the corona radiata
surrounding ovum and providing nutrients
sperm head enlarges to become the ____
male pronucleus
the ovum completes its _____ divsion at this time (when sperm head enlarges) to become the _____
second meiotic
female pronucleus
both pronuclei fuse and the ______ intermingle to form a single _____ cell, or ____
chromosomes
diploid
zygote
the chromosomes of the zygote arrange in preparation for the _______. the two daughter cells are called _____
1st cleavage division
blastomeres
rapid cell division without a change in the size of the original zygote is called ___
cleavage
16 blastomeres = ____
morula
zygote is the _____, and it is also known as
union of sperm and ovum
conceptus
morula is a _____
cluster of cells that remain the same size but the cells become smaller and smaller with each divison
when does morula become blastocyst
secretions cross the zona pellucid enter the morula forming a fluid cavity
fertilization stages
1. =
2. =
3. = (hours too)
4. = (hours too)
5. = (days too)
6. = (days too)
7. = (days too)
8. = (days too)
- ovulation
- fertilization
- zygote (24 hours)
- two cell stage (30 hours)
- four cell stage (day 2)
- blastocyst (day 4-5)
- enters uterus
- implantation of blastocyst (day 7)
the blastocyst enters the uterus _____ days after fertilization
6-7
implantation is complete by ____ days post ovulation or ____ days post fertilization
11-12
9-10
2 parts of a blastocyst
trophoblast (outer cell)
embryoblast (inner cell mass)
trophoblast becomes
embryoblast becomes
placenta and chorion
embryo, yolk sac, and amnion
once the ______ disappears, the blastocysts implants in the uterus
zona pellucida
after ovulation, progesterone causes _____ or ____ of the endometrium, allowing implantation
differentiation
decidualization
the implantation window begins ____ days after ovulation and lasts about ____ days
6-8
4
without fertilization, _____ and ____ drop and ____ occurs
estrogen
progesterone
menstruation
with fertilization, _____ maintains the endometrium, endometrium remains _____
progesterone
decidualized
trophoblast differentiates into what 2 layers
syncytiotrophoblast
cytotrophoblast
syncytiotrophoblast produces
hCG
syncytiotrophoblast invasively ____ the endometrial stroma, and blastocyst sinks into the endometrium. Eroded spaces are called _____, and those become the _____ of the placenta
erodes
lacunae
intervillous spaces
cytotrophoblast produces
finger-like projections that extend into the forming lacunar network
what are the finger-like projections produced by the cytotrophoblast called
primary chorionic villi
chorion frondosum
vs
smooth chorion/chorion Laeve
villi directly at the implantation site (early placenta)
vs
all the remaining villi around the gestational sac (chorionic membrane)
the decidua cells of the endometrium increase in size and content for implantation due to which hormone
progesterone
_______ cells of the embryo produce hCG regardless of the location of implantation of pregnancy thus supporting the _____ on the ovary
trophoblastic
corpus luteum
the endometrium will undergo a decidual reaction with an ectopic pregnancy resulting in what we call a ______
pseudo sac
if a pregnancy occurs in a bicornuate uterus this decidua reaction will occur in the _________ making it look like _____
non pregnant horn
twin pregnancy
decidua basalis (what/becomes)
the part of the decidua underlying the conceptus
eventually becomes the maternal side of the placenta
decidua capsularis
the part that covers the gestation sac
decidua parietalis (vera)
all remaining decidua
the opposing layers of the decidua _____ and ____ can be identified on early US. Used to rule out pseudogestational sac
parietalis
capsularis
the decidua ___ and ____ fuse
vera
capsularis
small spaces occur between the ______ and the ______. By day ___ from conception these spaces from the amniotic cavity
inner cells mass
trophoblast
9
the blastocyst cavity is called the _______ when the amniotic cavity is formed
primitive yolk sac
double bleb sign (what/seen on ___ at what time)
two blebs represent early amnion and yolk sac
seen on EV at around 5 1/2 weeks
the inner cell mass becomes the _______ (embryonic disc) at ____ weeks LMP
bilaminar
4
2 layers of bilaminar (embryonic) disc and what they form
epiblast: gives rise to nearly all cells of embryo
hypoblast: contributes to the formation of primitive ectoderm
gastrulation
formation of the 3 layers of the trilaminar disc (5 weeks)
3 layers of trilaminar disc names and what they form in the order of differentiation
endoderm: inner; linings of GI/resp tract
ectoderm: outer; forms CNS and stuff like hair, nails , skin, teeth
mesoderm: middle; generally forms muscle and bone
neurulation begins at ____ conception or ____ LMP
week 3
week 5
neurulation is the formation of hat three things
neural plate
neural folds
neural tube
neural tube closes around day ____ LMP
40
neural tube starts to close in the _____ and then progresses to the ____
middle
ends (caudal/cephalic)
zygote
blastocyst
embryo
fetus
fertilized ovum
when fluid enters the zygote at morula stage
inner cell mass differentiates
after 10 weeks completed LMP when embryogenesis is complete
allantois
diverticulum (pouch) of yolk sac
forms umbilical vessels and part of urinary bladder formation
physiological midgut herniation (occurs when, what happens, should measure under)
at 7 weeks and returns back by 12 weeks
gut herniates then rotates back
measure under 7mm
the GS grows ____/day
the embryo grows ____/day up to ___ weeks
1.1mm
1-2mm
8
yolk sac - _____ is the upper limit of normal before 10 weeks
6mm
6w0d= _____ MSD (mean sac diameter)
7w0d= _____ MSD
8w0d= _____ MSD
1.5cm
2cm
3cm
6 week CRL =
7 week CRL =
3-4mm
12-14mm
qualitative can detect at ____ LMP
4 weeks (urine)
quantitative can detect _____ LMP
23 days (blood - b hCG)
a b hCG test plateaus at ___
8 weeks
FIRP
SIS
TIS
and compare numbers to FIRP
1st international reference preparation
2nd international standard (1/2 of FIRP)
3rd international standard (same as FIRP)
discriminatory zone
is a range of serum b hCG concentrations which a GS can be visualized on US
b hCG of 100 mIU/ml SIS (2000 FIRP) = see a small GS by EV = ____ weeks LMP
4
b hCG of 1800 mIU/ml SIS (2600 FIRP) = see a ______ GS transabdominally = ____ weeks
5-10mm
5-6
fetal heart motion should be detected if CRL is ______ or greater by EV
7mm
b hCG doubles every ____ until ____ weeks gestation
2 days
8
a condition where a woman feels pregnant and isnt
pseudocyesis
if 12-14 weeks do a CRL and a ____
BPD
The amnion and chorion fuse by how many weeks
16
Corpus luteum on the ovary maintains progesterone until ______. _____ takes over after.
12 weeks
placenta
Embryo week 4
Epiblast – nearly all the cells of the embryo
Hypoblast - amnion
Embryo week 5
gastrulation, neurulation
At 1000 mIU/ml SIS a ____ should be identified in the uterus by ___
GS
EV
CRL is used up to ____
13 weeks
