First Trimester OB

what trimester is the most important

first trimester

What weeks does organogenesis occur

9-10 weeks

The first trimester is so important because

organ differentiation occurs

how many weeks is the first trimester

12 weeks after first day of last period

the ruptured follicle turns into

the corpus luteum

how big can the corpus luteum get in pregnancy

6-7cm

what cells secrete HCG when implantation happens

trophoblastic cells

what is the purpose of the secondary yolk sac

provides nutrients to early fetus 

what does the secondary sac form between

amnion and chorion

What determines placenta placement

where implantation happened

what week does the GI tract develop

4-5

during weeks 4-5 the neuroplate develops into

neurotube

during weeks 4-5 the lungs

begin to develop

When does the heart begin to beat

45 days past conception (week 6)

What does the primitive brain consist of

prosencephalon

Mesencephalon

Rhomencephalon

The forebrain is the 

prosencephalon

the midbrain is the

mesencephalon

the hindbrain is the

rhombencephalon

when does the formation of anterior and lateral abdominal walls start

weeks 7-8

the yolk sac fused with what to make the umbilical cord

vitelline duct 

the chorionic villi become what

the placenta

what week does mineralization of skeleton begin

8 weeks

At 8 weeks what does the small bowl do

herniates at base of umbilical cord

what week do fetal kidneys appear

week 10

by the end of week 10

major organ systems are established

swallowing starts at what week

week 12

the decidualized endometrium differentiates into what three areas

decidua basalis

Deciduous capsularis

Deciduous parietalis

what is the decidua basalis 

implantation site

Deepest layer of placenta 

what is the decidua capsularis

thin portion of endometrium

What is decidua parietalis

remaining endometrium

Unoccupied by implanted ovum

maternal and fetal blood…

DO NOT MIX

the placenta is divided into 

chorionic plate

Basal plate

Placental substance

what portion of placenta touches the amniotic membrane

chorionic plate

what portion of placenta touched the uterus

Basal plate

what portion of placenta is between basal and chronic plate

Placental substance 

placenta begins forming during

5th week

proliferating chorionic tissue releases

HCG

what does the placenta provide

O2 and nutrients

The placenta removes 

waste products 

what hormones does the placenta secrete

estrogen and progesterone

what is the innermost membrane of developing embryo

amnion

the amnion is within the

chorion

what is the outermost tissue of developing embryo 

chorion 

by what week do the chorion and amnion fuse

week 16

main structure that produced amniontic fluid

urinary tracts

main importance of amniotic fluid

symmetrical growth

Temp regulation

Movement

what is the most accurate dating tool in pregnancy 

crown rump length 

what does the yolk sac measure

less than 6mm

a double sac sing is a

pseudo sac

mean sac diameter is what

sum of length depth and width of gestational sac divided by 3

what is the umbilical cord composed of

two umbilical arteries and one umbilical vein 

what does the umbilical vein do

bring oxygenated blood from mom to baby

Difference between quantitative vs qualitative

quant gives number

Qual gives yes or no