Anatomy of the placenta lecture

Question 1

what is the placenta

Answer 1

complex temporary structure expressed during the third stage of labour
dualistic origin derived form both the mother and foetus
connection through umbilical cord, maternal and fetal blood do not mix
protects embryo and foetus exchange

Question 2

fetal part of placenta

Answer 2

develops form chorion fondosum

Question 3

maternal side of placenta

Answer 3

decidua basalis

Question 4

which hormones does the placenta secrete

Answer 4

oestrogen and progesterone

Question 5

gross anatomy of the mature placenta

Answer 5

flattened discoid organ
20cm diameter
2.5 cm thick at centre and thins out towards circumference
450-500g
fetal surface covered with amnion 9inner membrane)umbilical cord inserted
maternal surface B attached to decide, formed by approx 15-20 cotyledons separated by sulci

Question 6

gross anatomy of mature membrane

Answer 6

basal and chorionic plates meet at edges
forms chorioamnion membranes where amniotic flus is contained

Question 7

what is the chorioamnion composed of

Answer 7

chorion (outer)
amnion (inner)

Question 8

what is the chorion derived from

Answer 8

trophoblast layer of blastocysts cells
opaque

Question 9

amnion

Answer 9

translucent
connective tissue base
non-iliarted epithelial cells

Question 10

gross anatomy of mature umbilical cord or funds

Answer 10

extends from fetal surface of placenta to umbilical areas of foetus
originates from duct between amniotic sac and rock sac
2 umbilical arteries which spiral around 1 umbilical vein in Whartons Jellu

Question 11

what is Whartons jelly

Answer 11

mucoid connective tissue

Question 12

what is in the image and label

Answer 12

umbilical cord

Question 13

implantation

Answer 13

Question 14

where is the placenta formed from

Answer 14

outer cell mass differentiating to trophoblast
forming placenta and membranes

Question 15

extravillous trophoblasts of first trimester

Answer 15

highly invasive
form cell columns that extend from endometrium to the inner third of the myometrium

Question 16

2 stages of placenta formation

Answer 16

prelacunar
lacunar

Question 17

prelacunar

Answer 17

day 7
blastocyst makes contact with the decider and placentation begins

Question 18

lacunar

Answer 18

formation for lacunae which will become intervillous spaces
filled with maternal blood- basal plate

Question 19

what does the trophoblast lineage give rise to in the human placenta

Answer 19

syncytiotrophoblast
villous cut-trophoblast
extravillous trophoblast

Question 20

what does the syncytiotrophoblast form

Answer 20

forms epithelial covering of the villous tree
main endocrine component of the placenta

Question 21

waht does the villous cytotrophoblast form

Answer 21

represents germinative population that proliferate throughout pregnancy and fuse to generate the syncytiotrophoblast

Question 22

extravillous trophoblast cells

Answer 22

non-proliferative
invade the maternal endometrium

Question 23

cell shape of cytotrophoblast cells that form the mural and polar trophoblast

Answer 23

cuboidal
covered externally with syncytial trophoblast

Question 24

label the image

Answer 24

Question 25

label the image

Answer 25

Question 26

what does the chorionic plate consist of

Answer 26

Primitive mesenchymal tissue containing branches of umbilical vessels Layer of cytotrophoblast & Syncytiotrophoblast Stem villi connected to chorionic plate

Question 27

what does the basal plate consist of

Answer 27

Part of layer of decidua basalis Degeneration of the outer Syncytiotrophoblast at the cytotrophoblast shell & decidua junction Cytotrophoblast shell Syncytiotrophoblast acts as a reservoir for blood

Question 28

vasculature of the basal plate

Answer 28

spinal branches of the uterine vessels through which maternal blood flows into intervillous space

Question 29

what does the septum consist of

Answer 29

decimal elements covered by trophoblastic cells

Question 30

areas between septa

Answer 30

cotyledons seen on maternal surface

Question 31

physiology of maternal placental circulation

Answer 31

Question 32

label the image of the placental villi

Answer 32

Question 33

short cord

Answer 33

traction and premature separation leading to insufficiency abruption

Question 34

long cord

Answer 34

cord around neck cord prolapse true knot

Question 35

hyper and hypo-coiled cord

Answer 35

intrauterine growth restriction, fetal demise, associated with hypertensive disorders, placental abruption, maternal diabetes, polyhydramnios

Question 36

anomalous insertions of the cord

Answer 36

marginal/Battledore, velamentous bifurcate – retained placenta, vasa previa, fetal blood loss - anaemia

Question 37

vasa previa

Answer 37

anaemia, fetal demise

Question 38

incorrect placenta implantation

Answer 38

early miscarriage

Question 39

abnormal trophoblast invasion

Answer 39

placenta accreta, pre eclampsia, infarctions, abruption, pre-eclampsia,

Question 40

low lying placenta and placenta previa

Answer 40

lower segment caesarean section, Short cord- traction and premature separation leading to insufficiency- abruption

Question 41

Bi lobed/Succenturiate lobe placenta

Answer 41

vasa previa, post-partum hemorrhage and infection