Physiology of Pregnancy and Puerpium Lactation

Question 1

the fertilised ovum divides and differentiates into what structure?

Answer 1

a blastocyst

Question 2

what is the name of the egg from its journey from the site of fertilisation to the endometrium?

Answer 2

blastocyst

Question 3

how many days does it take for the blastocyst to ENTER the uterus?

Answer 3

3-5 days

Question 4

how many days does it take for the blastocyst to IMPLANT in the uterus?

Answer 4

5-8 days

Question 5

what do the inner cells of a blastocyst form?

Answer 5

embryo

Question 6

what do the outer cells of a blastocyst form?

Answer 6

placenta

Question 7

name the cells of the blastocyst that invade the endometrial cavity

Answer 7

trophoblast cells (surface layer of the blastocyst)

Question 8

what signifies the end of implantation?

Answer 8

when the blastocyst is completely buried in the endometrium

Question 9

how many days after fertilisation is the end of implantation?

Answer 9

day 12

Question 10

the placenta is derived from what 2 types of tissue?

Answer 10

trophoblast

decidual tissue

Question 11

another word for trophoblast cells?

Answer 11

chorion

Question 12

how are placental blood vessels formed?

Answer 12

1. trophoblast cells invade decidua and breaks down capillaries to form cavities for maternal blood
2. embryo creates blood vessels which insert into the cavities to form villi
   N.B foetal capillaries and maternal blood are separated by a thin layer to prevent cross contamination

Question 13

in what week of pregnancy are the placenta and foetal heart functional?

Answer 13

week 5

Question 14

what does HCG do?

Answer 14

signals the corpus luteum to continue secreting progesterone

Question 15

what effect does progesterone have on decidual cells?

Answer 15

stimulates them to concentrate glycogen, protein and lipids

Question 16

why does the placenta contain villi?

Answer 16

increases contact area between uterus and placenta

allows more nutrients and waste to be exchanged

Question 17

the thin membrane separating mums blood from babys in the placenta is located in what space?

Answer 17

intervillous space

Question 18

what makes up umbilical blood? how oxygenated is it?

Answer 18

mix of arterial and venous blood

poorly oxygenated

Question 19

how oxygenated is mums blood in the placenta?

Answer 19

oxygen rich

Question 20

describe the transport of oxygen within the placenta?

Answer 20

O2 diffuses from M to B’s circulation

CO2 diffuses from B to M’s circulation

Question 21

what vessel transports oxygen rich blood to the foetus?

Answer 21

umbilical vein (because it’s LEAVING the placenta)

Question 22

what vessel transports maternal oxygen poor blood?

Answer 22

uterine veins

Question 23

what 3 factors facilitate oxygen transport to the foetus?

Answer 23

foetal Hb
higher Hb concentration in fetal blood
Bohr effect

Question 24

what is the bohr effect?

Answer 24

fetal Hb can carry more oxygen in low pCO2 than high pCO2

Question 25

PO2 is higher in mum/baby | PCO2 is higher in mum/baby

Answer 25

mum | baby

Question 26

a fetus has a __% higher Hb concentration than an adult; why is this?

Answer 26

50 | to give them an increased ability to carry O2

Question 27

what 2 electrolytes can only go from mother to child?

Answer 27

iron | Ca

Question 28

what substance is the fetus' main source of energy?

Answer 28

glucose

Question 29

exchange of water increases during pregnancy T or F

Answer 29

T

Question 30

what substances diffuse freely across the placenta?

Answer 30

fatty acids

Question 31

glucose crosses the placenta via what process?

Answer 31

simplified transport

Question 32

HCG peaks at how many weeks gestation?

Answer 32

10

Question 33

human chorionic somatomammotropin is produced from around week _ of pregnancy

Answer 33

5

Question 34

what does HCS do?

Answer 34

GH-like effects eg on protein tissue decreases insulin sensitivity breast development

Question 35

why are pregnant women more insulin resistant?

Answer 35

to provide more glucose for the foetus

Question 36

what does progesterone do?

Answer 36

develops decidual cells decreases uterine contractility preps for lactation

Question 37

what does oestrogen do?

Answer 37

enlarges uterus breast development relaxes ligaments

Question 38

what pituitary hormone is also synthesised by the placenta? what does it stimulate release of?

Answer 38

CRH | ACTH

Question 39

effect of increased CRH in pregnancy?

Answer 39

excess cortisol can cause insulin resistance -> GDM | excess aldosterone can cause HT

Question 40

main consequence of excess HCG production? why is this?

Answer 40

hyperthyroid | can mimic TSH

Question 41

what effect can pregnancy have on the parathyroid gland and why?

Answer 41

hyperparathyroidism | increased Ca demands

Question 42

cardiac output increases/decreases in pregnancy, why is this?

Answer 42

increases | increased demands from the uteroplacental/renal circulation and inc metabolism

Question 43

CO increases by __%

Answer 43

30-50

Question 44

at what gestation does CO peak?

Answer 44

24

Question 45

its normal to have ECG changes and heart sounds in pregnancy T or F

Answer 45

T

Question 46

a HR of up to _ BPM is normal in pregnancy

Answer 46

90

Question 47

when does BP drop in pregnancy and why?

Answer 47

2nd trimester | uteroplacental circulation expands and TPR decreases

Question 48

when pregnant with twins CO ___ and BP ____ more

Answer 48

increases | decreases

Question 49

___ increases proportionally with CO

Answer 49

PV

Question 50

how much iron is needed in the second half of pregnancy per day?

Answer 50

6-7mg a day

Question 51

what effect does progesterone have on the lungs?

Answer 51

instructs the brain to lower CO2 levels to increase O2 consumption (needed by fetus, placenta and mother)

Question 52

GFR decreases in pregnancy T or F

Answer 52

F, increases as does renal plasma flow

Question 53

what happens to reabsorption of ions in the kidneys in pregnancy?

Answer 53

increases

Question 54

3 main features of pre-eclampsia?

Answer 54

pregnancy induced hypertension proteinuria oedema

Question 55

what happens to the kidneys in pre-eclampsia?

Answer 55

renal blood flow and GFR decrease | get salt and water retention = oedema

Question 56

biggest risk for pre-eclampsia?

Answer 56

previous pre-eclampsia

Question 57

presentation of eclampsia?

Answer 57

SEVERE | vascular spasms, extreme hypertension, chronic seizures, coma

Question 58

Tx of eclampsia?

Answer 58

vasodilators | CS

Question 59

average weight gain of the mother in lbs

Answer 59

24lbs

Question 60

how much extra protein should be ingested by mum?

Answer 60

30g per day

Question 61

at what trimester is mum's metabolism at its most anabolic? why is this?

Answer 61

1st and some of 2nd need to store energy and glucose for the foetus growing breasts/uterus/weight

Question 62

at what trimester is the mother most insulin resistant?

Answer 62

3rd trimester

Question 63

what effect does progesterone have on uterine contractility?

Answer 63

inhibits it

Question 64

what produces oxytocin?

Answer 64

POSTERIOR pituitary gland

Question 65

what does oxytocin do?

Answer 65

increases uterine excitability by: 1. stimulating uterus to contract 2. stimulating placenta to make prostaglandins (stimulates more contractions)

Question 66

describe the positive feedback mechanism of labour?

Answer 66

stretching of structures eg the cervix by the fetal head: increases contractility by increasing oxytocin release increases abdo contractions caused by reaction to pain

Question 67

what hormone stimulates oxytocin receptors on the uterus?

Answer 67

oestrogen

Question 68

name the 1st stage of labour and how long it lasts

Answer 68

cervical dilatation | 8-24hrs

Question 69

name the 2nd stage of labour and how long it lasts

Answer 69

passage through birth canal | few mins to 2 hours

Question 70

name the 3rd stage of labour

Answer 70

expulsion of the placenta

Question 71

describe the role of oestrogen in lactation?

Answer 71

growth of the ductile system

Question 72

what hormone develops the lobule alveolar system

Answer 72

progesterone

Question 73

oestrogen and progesterone inhibit/promote milk production

Answer 73

inhibit | there is a drop after birth which increases lactation

Question 74

what 2 hormones need to be increased for milk to be produced?

Answer 74

oxytocin | prolactin

Question 75

steroids are given to premature babies

Answer 75

30 | protects the brain