Placenta Flashcards
Describe the origin of the placenta
arises from maternal origin (decidua basalis) and fetal origin ( chorion frondosum: {syncytiotrophoblast/cytotrophoblast/Extra embryonic mesoderm(somatic)})
Placent is the site of what?
Material exchange with mother (oxygen/CO2, etc)
Embryonic layer of placenta
embryonic frondosum, consists of 3 layers making up chorion
Maternal contribution to the placenta
decidua basalis
Decidua
Basalis: portion of endometrium underlying implantation site
capsularis: portion overlying implanted embryo. separates it from uterine cavity
parietalis- remainder of endometrium
DC: what it is, where it is, its fate.
What it ISNT
portion overlying the implanted embryo and separating from it from the uterine cavity
eventually lost as the amniotic cavity enlarges and occupies all the space in the uterine cavity
not part of the placenta
DP: what it is, where it is, what it isn’t
the rest of the endometrium behind the DC
It isn’t part of the placenta
Fusing of three structures include the
decidua parietalis, chorion laeve, and amnion
Chorion fondosum: referred to as _______ and connects with the ________
chorionic plate; decidua basalis
site of villi development: agents of exchange between maternal and fetal systems
fetal surface of placenta should have chorionic (fetal) blood vessels
Exchange System between mom and embryo
- Umbilical cord (extends from embryo)
- chorionic plate (amniotic wall)
- basal plate (interface between fetal/maternal contributions)
Chorionic villus
outgrowths from cytotrophoblast : primary, secondary, tertiary: sites of oxygen and CO2+waste exchange
Primary chorionic villi
solid outgrowths that protrude into syncytiotrophoblast
Secondary chorionic villi
Have a core of loose connective tissue. grows into primary villi about the third week of development
Tertiary Chorionic villi
contain embryonic blood vessels
blood vessels connect up with vessels that develop into the chorion and connecting stalk; begin to circulate blood about the third week of development
Placental Barrier consists of (slide 20 for picture)
a) Syncytiotrophoblast
b) Cytotrophoblast
c) Extraembryonic mesenchyme
d) fetal endothelium (single layered wall of fetal capillaries)
Placenta membrane: what is ins’t, and substances that may pass through it
it isn’t a strict barrier
harmful pathogens include rubella, measles, herpes, cytomegalovirus, varicella, poliomyelitis
drugs: antibiotics, valium, librium, xanax, lithium, thalidomide, warfarin, isotretinoin, nicotine, alcohol, phenytoin
good stuffL 02, co2, glucose, free fatty acids, vitamins
Isotretinoin
used to treat severe acne
varieties include sotret, claravis, amnesteem
Substances that cross the placenta
isotretinoin (acne medication)
phenytoin (anti-epileptic)
warfarin (anticoagulant)
Erythroblastosis fetalis (Rh factor)
If expressed by baby’s blood cells (Rh+), Rh- mother will produce antibodies that will attack any future pregnancy that is Rh+: destroys fetal RBCs
Symptoms of Erythroblastosis in Baby
Anemia (low hemoglobin/RBCs in blood)
edema (swelling under surface of the skin)
enlarged liver or spleen
hydrops (fluid throughout body tissues, including spaces containing the lungs, heart and abdominal organs)
Newborn jaundice
Prevention of Erythroblastosis Fetalis
RhoGAM
Human immunoglobin with antibodies against the Rh Factor
PRevents maternal antibody response to Rh-positive cells for the fetus
Chorion fondosum is the site of which development?
a) umbilical chord
b) villi
(chorionic plate)
answer: villi
Cotyledons
maternal surface of placenta “cotyledons” looks like meat patties
Chorionic villus sampling
2 means: Transcervical procedure and Transabdominal procedure (amniocentesis)
- Test for familiar genetic disorders, advanced maternal age (chromosomal abnormalities
- Chorionic villus sampling can be done earlier in pregnancy (10-12 weeks) than amniocentesis (usually done at 15-20 weeks)
Amniocentesis
14-15 weeks, tests for genetic disorders and problems resulting from age of mother
Fetal blood circulation: which veins/arteries carry what and to where
Oxygenated blood is carried from the maternal arteries to the fetal veins which delivers O2 rich blood to the rest of the body; the fetal arteries carry deoxygenated blood back to the mother by diffusion through the arteries into the intervillus space
Jaundice, hydrops (fluid throughout the body’s tissues, including spaces containing the lungs, heart, and abdominal organs), enlarged liver or spleen, anemia, edema may be the result of
Erythroblastosis
Treatment for Erythroblastosis consists of
RhoGAM
human immunoglobin with antibodies against the Rh Favtor, prevents maternal antibody response to Rh-positive cells for the fetus
Placental Barrier
- syncytiotrophoblast
- cytotrophoblast
- extraembryonic mesenchyme
- embryonic endothelia
Placenta as an Endocrine Organ
Synthesizes glycogen, cholesterol, and fatty acids
nutrients, oxygen, some immunoglobins
removes waste products
Synthesizes gonadotropin hCG- stimulates production of progesterone by the ovary (corpus luteum) (syncytiotrophoblast synthesizes/secretes these)
estrogens and progesteron
Chorinonic somatomammotropin is produced where?
the placenta
hPL is what, and produced where?
human placental lactogen (hPL) produced by the placenta
- induces lipolysis and elevates free fatty acids in the moth. “growth hormon” of the fetus
I’m a steroid that suppresses contractility in uterine smooth muscle, what am I?
where am I made?
progesterone
the placenta
Placental Calcification
sign of placental aging. pattern is seen in other aging tissues
lithopedion
fetal death with an ectopic pregnancy. fetus is too large to be reabsorbed by the body and calcifies
