Importance of Placenta

Question 1

what cells do foetal part of placenta mostly develop from

Answer 1

trophoblast cells of embryonic blastocyst

Question 2

what do trophoblast cells invade (2)

Answer 2

• decidua (maternal uterus)
• including spinal arterioles

Question 3

what does trophoblast invading spinal arterioles do

Answer 3

initially block maternal flow into placenta

Question 4

what does the initial block of maternal flow cause early placenta environment to be developing in

Answer 4

hypoxic environment

Question 5

consequence of exposure to higher O2 concentrations for developing placenta

Answer 5

impairs placental development

Question 6

what are chorionic villi

Answer 6

nutrient exchange units of placenta

Question 7

the chorionic villi containing foetal capillaries are bathed in maternal blood by when

Answer 7

second trimester

Question 8

during second trimester at what volume (general) is maternal blood flow occurring and at what velocity (general)

Answer 8

• high volume
• low velocity

Question 9

how are functions of placenta increased overtime

Answer 9

adaptations are made

Question 10

is the rate of placental growth constant throughout pregnancy

Answer 10

no, slows down

Question 11

remodeling of maternal blood vessels involves what

Answer 11

• expanding their diameter
• removing muscle layers that would constrict capillaries (as they do in other maternal vascular beds)

Question 12

in second or later pregnancy, how does the weight of placenta compare to those in first pregnancy

Answer 12

heavier

Question 13

does parity or offspring sex have a bigger effect on placenta weight

Answer 13

parity

Question 14

what makes up placental efficiency ratio

Answer 14

foetal weight to placental weight

Question 15

what can low ratio of placental efficiency indicate

Answer 15

poorly functioning placenta that does not effectively transfer nutrients to foetus

Question 16

are foetal weight and placental weight positively or negatively correlated (in general, full-term babies)

Answer 16

positively

Question 17

what is having a light placenta associated with

Answer 17

poor foetal growth
(born small for gestational age)

Question 18

for poor foetal growth (ie/ growth restricted) babies due to poorly functioning placentas (ie/ light placenta), how was O2 delivery

Answer 18

reduced

Question 19

is O2 higher in umbilical vein or umbilical artery

Answer 19

umbilical vein

Question 20

blood of umbilical vein route

Answer 20

from placenta to foetus

Question 21

blood of umbilical artery route

Answer 21

foetus to placenta

Question 22

light placenta is also associated with increased risks of

Answer 22

still birth

Question 23

placental measures of are also predictive of what

Answer 23

• poor personal health in offspring

Question 25

what happens to placental growth in late pregnancy although foetus is still growing rapidly

Answer 25

slows

Question 26

in normal pregnancy does foetal growth become restricted, why / why not

Answer 26

• restricted by placental capacity to deliver nutrients

Question 27

what predicts the weight of newborn baby

Answer 27

placental weight and function

Question 28

poor placental growth and function restrict (?) and increase risks of (2)

Answer 28

• restrict foetal growth
• increase risks of still birth and poor health of offspring

Question 29

(4) major functions of placenta

Answer 29

• nutrient, gas, waste exchange
• hormone production
• protection from environment (toxins, pathogens)
• immune protection

Question 30

what is the importance of the placenta for mother

Answer 30

placental signals are essential to coordinate maternal adaptations to pregnancy

Question 31

what do maternal adaptations to pregnancy allow regarding placenta

Answer 31

• mothers body to supply O2 and nutrients & remove wastes from foetus via placenta

Question 32

list a maternal adaptation to pregnancy that is preparative

Answer 32

• facilitating changes that prepare for supporting newborn thru lactation

Question 33

what are some hormones produced by the human placenta

Answer 33

• steroid hormones (incl progesterone)
• human chorionic gonadotropin
• placental lactogens
• growth hormone