Placenta Flashcards
what is the average weight of the placenta?
400-650G
what is the 1st thing that is done after the placenta is delivered?
check it is all in tact because if it is left it can cause infection
what can be seen on the chorionic side of the placenta?
chorionic vessels
what are the 3 vessels of the umbilical cord?
umbilical vein
2 umbilical arteries
what is wartins jelly?
protects the vessels of the umbilical cord from damage
what is the shiny surface of the placenta?
basal plate
what is the maternal side of the placenta?
basal plate
what provides the nutrients in early pregnancy?
glandular secretions From the endometrial glands
what are spiral arteries?
circular arteries that exist in the uterus outside of pregnancy
deliver blood to the placenta
blocked by the extravillous trophoblasts
what are extravillous trophoblasts?
leave the cytotrophoblast and invade the blood vessels in the endometrium
they end up blocking the vessels
can also invade the myometrium to a certain extent
invade the spiral arteries
remodelling the spiral arteries
what is the space that the blood enters around the villous trees called?
intervillous space
how long do the villi form plugs for?
until around week 12
during early pregnancy how is the syncytiotrophoblast layer maintained and renewed?
systematic replaced by the incorporation of the mononuclues of the cytotrophoblast which will last into the syncytiotrophpblast layer
how does placental nutrient transport work for maternal blood?
maternal blood (rich in oxygen and nutrients) flows from the uterine arteries into the large blood sinuses surrounding the villi then back into the uterine veins
how does the placental nutrient transport work for fetal blood?
fetal blood (low in oxygen and nutrients) flows through umbilical arteries to capillaries of the villi and returns through the umbilical vein to the foetus
what are the endocrine functions of the placenta?
production of human chorionic gonadotrophin
-takes over from the corpus luteum and produces oestrogen and progesterone and placental lactose
what are the mechanisms of nutrient transport?
-diffuson
-paracellular diffusion
-transporter-meediated transfer
-endocytosis-exocytosis
what produces HCG?
syncytiotrophoblast cells
what is the function of HCG?
-can be detected in pregnancy tests
-maintains the corpus luteum before the placenta develops
Which vessel transports blood rich in oxygen and nutrients to the fetus?
umbilical vein
what is the most common complication of pregnancy?
miscarriage
what is miscarriage?
the loss of a pregnancy during the first 23 weeks (after 13 weeks - late miscarriage)
what is stillbirth?
death of a baby after 24 weeks of gestation
what is fetal growth restriction?
-failure to reach genetically pre-determined growth potential
-birth weight below 5th centile of growth charts
-affects 5-10% of pregnancies in UK
-increases risk of stillbirth, childhood morbidities and disease in adulthood
what is pre-eclampsia?
new onset hypertension (>140mmHg systolic >90 diastolic) and proteinuria occurring after 20 weeks
-can be serious for baby and mum
-if left untreated can progress to eclampsia
what is the barker hypothesis?
inadequate nutrition in uterus programmes the foetus to have metabolic characteristics that can lead to future disease
what is eclampsa?
life threatening conditions characterised by lateral seizures
what is the real treatment for pre-eclampsia?
deliver the placenta
what are the large lobes of the placenta that contain the villus tree?
cotyledons
