Pregnancy Physiology

Question 1

where does fertilisation most commonly occur

Answer 1

ampulla

Question 2

when is the blastocyst transported to the uterus

Answer 2

days 3-5

Question 3

when does the blastocyst implant in the uterus lining

Answer 3

day 5-8

Question 4

what do the inner cells of the blastocyst become

Answer 4

the embryo

Question 5

what do the outer cells of the blastocyst become

Answer 5

the placenta

Question 6

what cells help the blastocyst penetrate + adhere to endometrium?

Answer 6

trophoblastic cells

Question 7

by what day is the blastocyst fully buried in the endometrium

Answer 7

day 12

Question 8

what is the placenta derived from

Answer 8

trophoblast + decidual tissue

Question 9

how are placental villi formed

Answer 9

trophoblasts differentiate into synctiotrophoblast- invade decidua + break down capillaries – forms cavities
Developing embryo sends capillaries into these projections- placental villi formed

Question 10

when is the placenta + foetal heart functional by

Answer 10

week 5

Question 11

what is the role of HCG in the nutrition of the foetus

Answer 11

signals corpus luteum to continue secreting progesterone-

this stimulates decidual cells to concentrate glycogen, proteins + lipids

Question 12

which vessel delivers oxygen rich blood to the foetus

Answer 12

umbilical vein

Question 13

which vessel returns oxygen poor blood back to the mother

Answer 13

uterine veins

Question 14

which 3 factors facilitate oxygen transport in fetal blood

Answer 14

1. fetal Hb- Increased ability to carry oxygen
2. higher Hb concentration in fetal blood
3. Bohr effect, fetal Hb can carry more oxygen in low pCO2 than in high pCO2

Question 15

what are the only electrolytes that can go from mother to child

Answer 15

iron + calcium

Question 16

how does glucose cross the placenta

Answer 16

simplified transport

Question 17

drugs that can cross placenta and harm the baby

Answer 17

alcohol 
nicotine
heroin 
cocaine 
tetracyclics
thalidomide
carbamazepine

Question 18

role of HCG

Answer 18

prevents degeneration of corpus luteum

Question 19

when is HCS (human chorionic somatomamotrophin) produced

Answer 19

from week 5

Question 20

role of HCS

Answer 20

protein tissue formation
decreases insulin sensitivity in the mother- more glucose for the foetus
involved in breast development

Question 21

function of progesterone

Answer 21

development of decidual cells
decreases uterus contractility
preparation for lactation

Question 22

function of oestrogen

Answer 22

enlargement of the uterus
breast development
relaxes ligaments

Question 23

what affect does the placenta releasing CRH have on the mother

Answer 23

increases ACTH- increases aldosterone

therefore increased cortisol

Question 24

what does increased aldosterone cause

Answer 24

hypertension

Question 25

what does increased cortisol cause

Answer 25

oedema | insulin resistance - gestational diabetes

Question 26

what effects does the placenta increasing calcium demand have on the mother

Answer 26

hyperparathyroidism (high calcium, high PTH)

Question 27

What cardiovascular changes are seen in the mother

Answer 27

increased CO (due to demand of fetal circulation) increased HR BP drops during 2nd trimester

Question 28

why does BP drop during 2nd trimester

Answer 28

expanding uteroplacental circulation- decreased peripheral resistance

Question 29

haematological changes seen in pregnancy

Answer 29

increased plasma volume erythropoiesis (increased in RBC) increased iron requirement

Question 30

respiratory changes in pregnancy

Answer 30

increased O2 consumption to meet metabolic demands of fetus

Question 31

role of progesterone in resp changes

Answer 31

signals brain to lower CO2 levels achieved by: increased RR Increased tidal volume

Question 32

renal changes seen in pregnancy

Answer 32

increased GFR + plasma flow

Question 33

how do postural changes affect renal function

Answer 33

upright- decreased supine- increased lateral position during sleep- increased

Question 34

what is pre-eclampsia

Answer 34

pregnancy induced hypertension + proteinuria

Question 35

what leads to proteinuria

Answer 35

kidney function declines- salt + water retention oedema decreased renal blood flow + GFR

Question 36

biggest risk for pre-eclampsia

Answer 36

previous pre-eclampsia

Question 37

what is given from 12 weeks if high risk for pre-eclampsia

Answer 37

75mg aspirin daily

Question 38

symptoms of eclampsia

Answer 38

LETHAL | vascular spasms, extreme hypertension, seizures, coma

Question 39

treatment of eclampsia

Answer 39

vasodilators + C section

Question 40

average maternal weight gain

Answer 40

24 lbs

Question 41

how many extra calories does a woman need

Answer 41

250-300

Question 42

what is given before labour to prevent intra-cranial bleeding

Answer 42

vitamin K

Question 43

role of progesterone + oestrogen in labour

Answer 43

progesterone inhibits contractility, oestrogen increases contractility

Question 44

where is oxytocin made

Answer 44

posterior pituitary

Question 45

role of oxytocin

Answer 45

increases contractions

Question 46

what does cervical stretching cause

Answer 46

further oxytocin release

Question 47

effect of oxytocin on the placenta

Answer 47

stimulates it to make prostaglandins | this stimulates more vigorous contractions of the uterus

Question 48

what stimulates milk production

Answer 48

prolactin

Question 49

what inhibits milk production

Answer 49

oestrogen | progesterone

Question 50

role of oxytocin in breast feeding

Answer 50

causes muscle contraction- smooth ejaculation of milk