chapter 56 Flashcards
what are the 3 decidual ?
- decidua basalis
- decidual capsularis
- decidual vera
chorion frondosum :
forms fetal part of placenta: contains villi
chorion laeve:
nonvillios part of chorion around gestational sac.
chorionic plate:
fetal surface of placenta
basal plate:
maternal surface of placenta
fetal placenta cells come from
cytotrophoblastic shell and anchoring villi.
approximately 40 % of fetal cardiac out put is directed through ____?
umbilical circulation
infraction is?
obstruction of blood flow.
placenta membranes is called ____?
barrier
battledore?
abnormal cordal attachments to placenta: edge of placenta.
when does the secondary yolk sac form ?
after the regression of primary yolk sac.
by 9 weeks yolk sac should be ___ mm
5 mm
what is the most common implantation of the placenta?
fundal posterior
amnion fuses with chorion by which week?
16th week
in 1st trimenster the fetus begins to ___?
excrete urine to fill amniotic cavity
amniotic fluid functions are:
permitting fetus room to move
allowing lungs to develop properly
serving as protective buffer for fetus
maintaining constant fetal body temp.
the umbilical cord is formed during 1st ___ weeks of gestation.
5 weeks
what is the percentage that the fetus has a single umbilical cord abnormality ?
25 to 50 %
the second surface is ____, the maternal portion of the placenta.
basal plate
Normal placenta should not exceed?
4 cm
placenta is separate from ____?
myometrium
If the bladder is full, what impression can it present?
impression of previa- falsely elongated
what is the best way to identify lower uterine segment,
transvaginal
high resistance flow is seen when there is ?
stenosis
normal flow pattern is ?
low-resistance
normal characteristic of placenta are?
measure 15 to 20 cm
weighs about 600 g
measures < 4 cm in thickness
discoid shape
placenta accreta
chorionic villi attach to myometrium without muscular invasion.
placenta abruption- dissecting
trickling down / showing of detachment. On the side
placental abruption- concealed:
not showing with severe pain. On the top
what happends with placental infacts
calcification may occur over time
gestational trophoblast disease
23 chromosons or 25
possible more fetuses or none.
mole tumor takes nutrients. grows rapidly.
placenta abruption refers to?
separation of normally implanted placenta prior to term delivery
Name the layers of endometrium.
Zona basalis and zona functionalis
What is succenturiate placenta?
If the placenta does not communicate with an anterior/posterior then it will be considered an accessory lobe placenta. Additional lobes joined to the main placenta.
What is battledores placenta?
The umbilical cord is inserted at or near the placental margin rather than in the center. Less than 2 cm of the edge.
What is velamentous placenta?
Is one of the two most common causes of vasa previa. Insertion of the umbilical cord into placental membranes, which cross over the cervix.
