Placenta Info + Related problems in medicine Flashcards
Wharton’s jelly
a placental cord gelatinous connective tissue: it is seen at partuition when it increases in volume to assist closure of placental blood vessels: matrix from jelly identified as potential stem cells
Umbilical cord blood stem cells have contributed treating ____ number of diseases since 1988
121
Umbilical Vein or Veins?
There are 2 during development: the right one deteriorates under normal circumstance @ second month of development: LEFT umbilical vein persists/devliering blood from placenta to the developing fetus
Persistent right umbilical vein
Uncommon vascular anomaly; present in 2/1000 births
normall the right umbilical vein begins to obliterate in the 4th week of gestation and disappears by the 7th week
Morphology of Placenta+with umbilical cord: which one should disturb us?
These are fine: Bilobed/Circumvallate/Succenturinate
VELAMENTOUS CORD
Velamentous cord
fetal blood vessels travel abnormally
pass through amniochorionic membrane before reaching the placenta
vessels are more exposed to trauma during the birth process
Abnormalities of Placental Implantation (2, with sub-distinctions)
Placenta previa: implantation of the placenta over the cervical os (opening)
Placenta accreta (abnormal trophoblastic invasion into the
1) muscular layer of the uterus (placenta increta)
2) surrounding tissue (placenta percerta)
Placental accreta/increta/percreta
When trophoblast grows past uterine wall into
1) Trophoblast grows too deep into the uterine muscle
1) Trophoblast grows through the uterine muscle (placenta increta)
2) Trophoblast grows beyond uterus into organs (placenta percerta)
Placenta Previa
1) Low hanging: near but does not cover cervix os
2) Partial covering of cervix OS
3) Total Covering
Placental Endorcrine Functions:
Synthesizes a) cholesterol b) fatty acids c) hormones d) glycogen
Hormones: hCG, progesterone (maintains endometrium), estrogen (estrodiol), human placental lactogen (hPL), induces lipolysis, elevating free fatty acids in mother
“growth hormone” of fetus
hPL
human placental lactogen (hPL): induces lipolysis, elevating free fatty acids in mother
growth hormone of the fetus
Placental calcification
theories include old age, reduced blood supply, smoking
pattern of calcification is seen in other aging tissues
Lithopedion
ectopic pregnancy termination in which body of dead fetus calcifies
Amniotic Fluid
permits symmetrical external growth
enables fetus to move frely
acts as a barrier to infection
permits normal fetal lung development
prevents adherence of aminion to embryo/fetus
helps maintain homeostasis (temp, fluids, electrolytes)
Oligohydraminos
Low volume of amniotic fluid
associated with renal agenesis+obstructive uropathy
complications: pulmonary hypoplasia and limb defects
Consequences of Oligohydraminos related renal agenesis
Potter syndrome
for normal development amniotic fluid must be brought into the lung by fetal breathing movements, leading to distension of the developing lung
polyhdramnios
high volume of amniotic fluid
associated with CNS anomalies and esophageal atresia
Amniotic band syndrome
tears in the amnion detach and surround fetus
or adhesions between the amnion and affected structures
may cause ring constriction or amputations of limps or digits
Development of blood vessels (2 ways)
- Vasculogenesis: blood vessels arise from coalescence of hemangioblasts, which arise from blood islands
- angioblasts- vessel formation via branches arising from existing vessels, major form via vasculogenesis
Major blood vessels form during _____
vasculogenesis
Vasculogenesis begins in
splanchnic layer covering yolk sack
Definitive hematopoietic stem cells (AGM)
formation of blood cells in the yolk sac transitory, definitive hematipoietic cells arise from mesoderm around the aorta
aorta-gonad-meonephros region (AGM)
the cells will colonize the liver
Hematopoietic tissue in the fetus
stem cells colonize the liver- major hematopoietic organ of the fetus
later stem cells from the liver colonize the spleen, thymus and ultimately the bone marrow
Path of hematopoietic cells —>
Aorta-gonad-mesonephros region (AGM)—> colonize the liver (major hematopoietic organ of the fetus)
