The placenta

Question 1

what cells develop into the placenta

Answer 1

trophoblast

Question 2

what cells develop into the foetus

Answer 2

inner cell mass

Question 3

the chorion ( trophoblast) splits into the 2 layers

Answer 3

synctiotrophoblast - outer layer - barrier and hormone secretion
cytotrophoblast
- inner layer contains prolific enzyme secretion - angiogenesis

Question 4

where is the placenta implanted

Answer 4

endometrium

Question 5

what artery supplies uterus

Answer 5

uterine artery - branch of internal iliac off aorta

Question 6

spiral arteries supply what

Answer 6

endometrium

Question 7

what artery which is a branch of ovarian supplies myometrium

Answer 7

arcuate artery

Question 8

what is special about the placenta villi

Answer 8

high surface area for gas exchange and layer of synctiotrophoblast covering fetal vessels

Question 9

do uterine contractions compromise flow

Answer 9

yes

Question 10

450ml/min

Answer 10

fetal flow

Question 11

500-600ml/min

Answer 11

maternal flow - 10% CO

Question 12

what does the umbilical cord consists of

Answer 12

carries fatal blood
2 arteries deoxygenated to placenta
1 vein oxygenated from the placenta

Question 13

what artery supplies umbilical

Answer 13

iliac artery

Question 14

what is the amnion

Answer 14

membrane over embryo - fills with amniotic fluid and become protective envrionemtn for embryo

Question 15

what is the chorion

Answer 15

double layer membrane formed by trophoblast cells gives rise to fatal part of placenta

Question 16

how many cotyledons does a placenta have

Answer 16

15-25

Question 17

what two techniques are used to look at placenta and embryo

Answer 17

Ultrasounds shows placental localization
Doppler shows umbilical cord insertion - flow
Shows health of umbilical flow

Question 18

what hormone support pregnancy in first trimester r

Answer 18

HCG

Question 19

what hormone is co-dependet in fatal adrenal function

Answer 19

oestrogen

Question 20

what hormone does ,,Anti-insulin action makes more glucose available for foetus

Answer 20

human placental lactose

Question 21

5 placental transfer mechanisms

Answer 21

passive diffusion - stérions 
facilitated diffusion - glucose 
active transport - aa and calcium 
endo/pinocytosis - immunoglobulisn 
osmosis - water

Question 22

fetus has higher O2 affinity of HbF how does a small left shift of fatal graph encourage what

Answer 22

O2 uptake

Question 23

delicate immunological truce prevents rejection of foetus what mechanisms

Answer 23

Placental secretion of phosphocholine (immune cloak)
Trophoblast has reduced antigenic (HLA) expression
Suppression of maternal cytotoxic T cell activity
Placental barrier to maternal lymphocytes

Question 24

what is antigen D

Answer 24

rhesus positive

need to give 72 hours post part

Question 25

ABO antibodies are IgM so do not cross the placenta RH D antibodies are IgG - small can they cross placenta

Answer 25

yes

Question 26

placenta praaevia | symptoms

Answer 26

``` Placenta lying partly or entirely over the cervical opening ( cervical OS) ``` • Usually painless • Visible bleeding usually matches level of shock painless bleeding

Question 27

Can be different grades deepening on extent | of covering of the internal os

Answer 27

I - placenta reaches lower segment but not the internal os II - placenta reaches internal os but doesn't cover it III - placenta covers the internal os before dilation but not when dilated IV - placenta completely covers the internal os

Question 28

Placental abruption symptoms

Answer 28

Separation of the placenta from the uterine wall, resulting in bleeding behind the placenta ( can be concealed - behind placenta or concealed track down to cervix) • Normally very painful • Shocked but may not have visible expected blood loss • Life threatening to the foetus

Question 29

What is a cord prolapse | what can the fetal head do

Answer 29

cord bulges through the cervix when membrane ruptures fatal head compresses cord during contraction cutting off umbilical flow

Question 30

pre-eclampsia | and symtoms for maternal

Answer 30

Hypertensive disorder of pregnancy due to poor placental perfusion placental vessels fail to develop so perfusion inadequate interpreted as shock from blood loss causing vasoconstriction so * Hypertension and proteinuria- main symptoms * May also present with: * Frontal/occipital headache * Visual disturbances * Epigastric pain * Oedema * Hyper-reflexia in foetus - growth retardation

Question 31

What is seen in the classic triad of ectopic pregnancy?

Answer 31

• Implantation of the embryo not in the uterine wall • Not all women will present with all three features vaginal bleeding amenorrhea ( absence of menstruation - missed periods 3 in a row) acute abdominal pain

Question 32

what is not seen in the classic triad of ectopic pregnancy

Answer 32

oligomenorrhea - infrequent menstrual periods

Question 33

A 30 y/o, 26 -week ``` pregnant lady presents to the GP reporting she has had a headache and upper abdominal pain for the past 24 hours. The GP takes her blood pressure which reads 160/120mmHg. She decides to take a urine dipstick which shows +++ for protein. What is the most likely diagnosis? ```

Answer 33

pre eclampsia

Question 34

A 34-week pregnant lady presents with a small amount of vaginal bleeding and lower abdominal pain. Her blood pressure is 85/62 and pulse is 118. What is the most likely diagnosis?

Answer 34

placental abruption

Question 35

A 35-week pregnant lady presents with painless bleeding from the vagina. Her pulse and blood pressure are normal. What is the most likely diagnosis?

Answer 35

placenta praevia