Placenta Lecture Flashcards
T embilical cord comes up from ___ the placenta and spreads across ___ ___ and branches into villi to increase the ___ ___. ____ ___ comes up into this plate and heads out into the villi.
Villi are covered with inner layer of _____ and an outer layer of _____ and are full of fetal blood, sit bathed in the lacuna, or lakes, which are full of ____ ____. The Mother’s ____ ____ spill the maternal blood into lacunae, this allows the maternal blood to come close to fetal blood, but the two do not mix.
Fetal blood gives off waste, absorbs nutrients and oxygen, and heads back through the cord to the ___. Maternal blood circulates, leaves the lacuna through ____ ____ ____ ____-.
below,
chorionic plate,
Surface area
Fetal blood
cytotrophoblast
syncytiotrophoblast
maternal blood
spiral arteries
fetus
lower pressure veinous drainage
In the fetus, oxygenation occurs in the _____. The umbilical arteries carry _____ ____to the ____, and the umbilical vein carries ______ _____ back to the _____.
placenta
deoxygenated blood
placenta
oxygenated blood
fetus
Wharton’s jelly: gelatinous substance that surrounds the _____; It is _____ ___, so it causes the blood vessels in the cord to _____ about 5 minutes after delivery
vessels
temp sensitive
collapse
Single umbilical artery occur 1% of births. With this comes a small increase in chance for ___ _____, so number of vessels in the cord is counted at__-__ week ultrasound
genetic anomalies (like Downs syndrome)
19-20th week
The fetus begins to make urine at about ___ ___ or so, and that pushes the ____ out to fuse with ____ ___ ___ (chorionic plate) & attaches to the wall or top of the uterus.
10 weeks
amnion
chorion placental disk
uterus
A delivery without having the water broken and the sac intact is called?
en caul
What hormones does the placenta make?
HCG (turns pregnancy test turn positive),
estrogen,
progesterone,
human placental lactogen
Human placental lactrogen does what?
prepares the breasts for lactation
Metabolically, the placenta makes?
Metabolic: makes glycogen, cholesterol.
The placenta exchanges waste from the fetus, nutrition and oxygen from the mother by 4 mechanisms, what are they and describe what they might move?
simple diffusion- water, gases, some drugs (Psychoactive drugs like opiods)
Facilitated diffusion: glucose
active transport: amino acids
pinocytosis: Igs like for pertusis, whooping cough,
Placenta is an isolation barrier- maintains sterile environment, maintains “immunologic privilege”- what does it prevent?
Some organisms can cross the placenta though, name 4:
keeps mom and baby’s blood from mixing; bc baby blood is foriegn to mom
CMV and rubella viruses
treponema pallidum
Listeria
If an RH+ baby comes into contact with RH- moms antiRH antibodies, what could happen?
Erythroblastosis fetalis: severe anemia in baby- RBCs get lysed by maternal antibodies,
Rhogam is synthetic____ against the Rh protein. After mom is injected, Rhogam can bind to any ____ ___ ___in maternal circulation and lyses those cells; mom’s cells are safe bc her RBCs are Rh negative. Mom’s immune system is not ____.
If a mom is Rh- whaen does she get rhogam?
antibodies
Rh+ fetal cells
sensitized
28weeks regardless of baby blood and the again after pregnancy if the baby was Rh+
To prevent ___ ____, doctors look for the ____ on the ____ side of the placenta after placental delivery. If uterus empty, it will contract down to squeeze the ____ ___, stopping blood from entering where the lacuna used to be. However, if any tissue is retained, ____ ____ continue to try to fill lacuna with blood and _____ results
Maternal hemorrhage
cotyledons
maternal
spiral arteries
spiral arteries
hemorrhage
During a Molar pregnancy, the ___ does not develop, but the _____ does, ___ fill with fluid- this needs to be evacuated.
fetus
placenta
villi
Membraneous or velementous insertion occurs when the cord inserts off of the___ ____ completely and in the ____ instead. This is fine until the ____ ___ and membranes are no longer supported like a balloon. The vessels can kink because it is not protected by ____ ____ which is like ____ the baby because it cuts off ___ ____.
placental disk completely and in the membranes
water breaks
Whartons jelly
like choking the baby bc cuts off gas exchange
An accessory or succinturiate lobe is an extra island of ____ tissue and can be _____ running in the membranes between the two _____ ____.
placental
vessels
placenta disks.
Vasa previa is when vessels (from ____ or ___ ____) are below the baby’s head running across the ____ ____. These vessels may rupture if the ____ ___ and cause the baby to rapidly exsanguinate. These babies are usually delivered early at ____ weeks by cesarean section
accessory or succinturiate lobe
cervical opening
water breaks
exsanguinate
35 weeks
Abnormal placentation occurs when trophoblastic tissue invades the maternal endometrium. Healthy maternal endometrium resists; ____ endometrium is not as good at resisting. If the pt has a history of many ____ ____ they are at higher risk. This is dangerous bc if the placenta does not detach after the baby delivers- still has a vast ___ ____ can ______ very dangerously.
Abnormal placentation
scarred
c sections
blood supply
hemorrhage
what are the types of abnormal placentaion? describe each
Placenta accreta- placenta implants over previous cesarean section scar abnormally attached to uterine myometrium, does not neatly separate after delivery
Placenta increta grows deeply into uterine wall
Placental Percreta- growing all the way through the uterus, invades bowel or bladder
If abnormal placentation is diagnosed early, what preventative actions can be taken? (5)
- More iron intake in pregnancy,
- may transfuse her before delivery,
- make an extra big incision so we can work quickly,
- use extra medicines that can help her tissue clot,
- have a cell-saver device to suction up the blood, spin it down and transfuse her own blood back to her.
_____ is when the placenta separates prematurely. This can be caused by _____, ____ ____ ____ or _____. It is very ____ for the mother and usually the baby needs to be ___ _____.
Cociane
High BP
trauma
painful
emergently delivered
Twin-twin transfusion syndrome occurs in placenta of ____ twins where a ___ ____vessel from one baby connects to a ___ ___ vessel from the other baby and allows blood run from one baby to the other. The “donor” twin unable to ____ or to make much ___ while the recipient twin becomes fluid _____.
Options for management include ___ ___, or fetal surgery- laser_____ of ____ ____.
monochorionic
high pressure
low pressure
grow or make much fluid
overloaded
early delivery
ablation of vasculation connections
The amniotic fluid provides a ____ for the fetus and the cord, allows fetal ____, and contains ____ ___ for the ___ that are made in the ___ ___, breathed in by developing fetus
cushion
movement
growth factor
lungs
fetal kidney
