L2:physiology of pregnancy Flashcards
weeks of trimester 1 (T1)
1-12
weeks of trimester 2 (T2)
13-26
weeks of trimester 3 (T3)
27-40
4 parts of T1 for foetus
fertilisation
implantation
initial development
placentation
5 parts of T2 for foetus
nervous system hair spine straightens pain proportions change
5 changes to mother in T2
placental growth uterus rises hypervolemia cardiac remodelling breast remodelling
5 changes to foetus in T3
growth fat deposition brain growth lung development blood cells
4 changes to mother in T3
braxton hicks
tiredness
restricted breathing
lactation
overall what happens to mother heart rate
increases
overall change to mothers blood pressure
doesn’t
overall change to mothers blood volume
increases
what happens to mother haematocrit
decreases
pattern of foetal heart rate change
dramatically increases in 1st trimester then plateaus
official start of pregnancy=
last menstrual period
when is conception in pregnancy
3 weeks
when is implantation in pregnancy
4 wks
other name for luteal phase
secretory phase
what does the blastocyst need to do before implantation
hatch from zona pellucida
3 factors of uterine epithelia
tight inter-cellular gap junctions
villi
glycocalyx
what in the uterine epithelia attracts the embryo
glycocalyx
what breaks down the zona pellucida
protease
what breaks down the glycocalyx
blastocyst signals uterine epithelium to break it down
what cells of the blastocyst integrate with the cell lining the uterus epithelia
trophoblasts
3 changes in the uterine epithelium the interaction between trophoblasts and uterine epithelium causes
migration of nuclei to basal compartment
changes in structure of stromal cells
start of decidualisation
what causes decidualisation
trophoblasts invade into primary decidua and produce protease and destroy these cells
an important cytokine involved in decidualisation
leukaemia inhibiting factor
what 2 cells do trophoblasts differentiate into after implantation
syncytial trophoblasts
cytotrophoblasts
outer layer of trophoblast=
syncytial trophoblasts
what are syncytial trophoblasts
multicellular –> big nucleated structure
what are cytotrophoblasts
single cellular inner layer
where does embryo development happen
in uterine wall itself
what forms in the cytoplasm of the syncytial trophoblasts
trophoblastic lacunae
what do trophoblastic lacunae contain/ do
nutrients for support (histotroph)
what rescues the corpus luteum
hCG
6 things progesterone leads to in early pregnancy
suppression of menses tender/ enlarged breasts fatigue urinary frequency nausea/ vomiting constipation
2 things pluriblast divide into
epiblast
hypoblast
epiblast –>
ectoderm
hypoblast –>
endoderm
what forms inbetween ectoderm and endoderm
mesoderm
amnion=
ectoderm and mesoderm
chorion=
trophoblast and mesoderm
yolk sac=
endoderm and mesoderm
what overtakes histotrophic support
haematrophic support
how does the embryo switch to haematrophic support
prompting remodelling of uterine spiral arteries
why do spiral arteries need remodelling
they have high blood pressure which can damage the embryo
what cells grow into the maternal spiral arteries
syncytial and cytotrophoblasts
what happens when the syncytial and cytotrophoblasts grow into the spiral arteries
leads to widening so blood can pool
how does the embryo access pool of blood
uses vili
what forms the embryo vili
syncytial trophoblasts
when does haematrophic support happen
around 5 weeks post conception
what happens at the same time of haematrophic support
foetal circulation system begins to develop
what is a primary vili
solid trophoblast
what is a secondary vili
invasion of mesoderm within trophoblast
what is a tertiary vili
foetal blood vessels penetrate vili
vili at week 9=
tertiary vili stem lengthen forming mesenchymal vili
vili at week 16
terminal extensions reach maximal length
vili at week 32
mature intermediate tertiary vili produce secondary branches = terminal vili
what is the umbilical cord
coiling of 2 veins around artery which feeds into villous tree
4 things transported in the placenta
respiratory gases
glucose
free fatty acids
lipids
how is glucose transported into foetus
via GLUT and oxidised in placenta
can foetus do gluconeogenesis
NO
what does the placenta express for lipid delivery
lipoprotein lipase
peak of hCG conc
3 weeks
2 things oestrogen’s do
relaxation of pelvic ligaments and increase elasticity of pubic synthesis
what is needed for oestrogen synthesis
foetal and placental cooperation
what can indicate placental function
progesterone
3 roles of progesterone
causes decidualization
increase oviductal/ uterine secretions
reduce uterine contractions
when is somato mammotropin secreted from
week 5
what is hypervolemia
too much fluid in blood –> maternal glow
effect of oestrogen in trimester 2
- increasing angiogenesis (via NO increase)
- act on hepatic system increasing ang2, renal absorption and aldosterone
effects of progesterone in trimester 2
- increases vasodilation, decreases peripheral resistance
- increases aldosterone levels
downside of progesterone in trimester 2
oedema
what does HR and stroke volume increase by in T2
HR 20% SV 20%
increase in heart size=
12%
what does breathing become in T2
thoracic
what happens to sensitivity to chemoreceptors in T2
lowered (–> deeper breathing)
what in the lungs stays to same
vital capacity
why does vital capacity stay the same
lose residual volume
what happens to the kidneys in T2
enlarge
enlarged kidneys causes (3)
increase waste excretion
increase Na+ absorption
increase blood flow
what is pregnant urine richer in
glucose and AA
what happens to the fetus at the end of pregnancy
engages
average weight gain in pregnancy =
24lb
what urine related pathology are you at higher risk of in pregnancy
UTIs
