3. hormonal changes and adaptations Flashcards
what happens to RBCs
- inrcreased synthesis, stimulated by erythropoietin
- anaemia due to dilution
- haematocrit falls to 32%
- 30% increase in intracellular 2-3, DPG (helps O2 release to fetus)
describe the way fatty acids are transported in the placenta
- triglycerides in LP release NEFAS due to LIPOPROTEIN LIPASE
- NEFAS transported across trophoblast cells by fatty acids transport proteins (FATP)
why is folate important
reduce neural tube defects
what are some fetoplacental hormones
oestrogen, progesterone
what are some functions of oestrogen
- stim. Renin-Angiotensin-Aldosterone Axis
- synth of liver FA and cholesterol
- growth of uterus
- prime uterus for labour
- anti-insulin activity
- CV adaptations to pregnancy
- cervical ripening
what are some functions of progesterone
- prep and maintain endometerium
- suppress maternal immune response to fatal antigens
- parturition
- substrate for glucocorticoid and mineralocorticoid production
- mammary gland growth
- inhibit uterine contractions, prevent cervix ripening
- lower maternal CO2
- stim. renin angiotensin axis
role of hCG
maintain corpus lute structure
what are the functions of hCG
- stimulate maternal thyroid activity:
bind to TSH receptor
LH-hCG receptor thyroid
stim activity via LH-hCG or TSH receptor
what is hPL
human placental lactogen
main role of hPL
modify metabolism of mother to facilitate energy supply of fetus
what are some functions/actions of hPL
- maternal lipolysis and increase NEFAs
- anti-insulin or diabetogenic action (more insulin = mobilise AA and glucose, and fetal protein synthesis)
- potent angiogenic hormone: fetal vasculature
what are some placental proteins
hPL
SP1
PAPP-A (pregnancy associated plasma protein A)
hCG
VEGF (vascular endothelial growth factor)
PLGF (placental growth factor)
Leptin
what is the main role of leptin
regulate growth and development
angiogenesis
hematopoiesis
functions of leptin
- stim placental AA and FA transport
- leptin=fetal birthweight
how is leptin secreted
both cytoplasms and syncitiotrophs
maternal levels higher
what observations change in pregnant woman
increase in HR and aortic CO
decerase in TPVR
why does TPVR fall in pregnant woman
-increased NO
-increased prostacyclins (PGI2, vasodilator)
-relaxin?
=VASODILATE
why does CO increase in pregnant woman
- Na retention
- oest: increase renin-aldosterone
- prog: inc aldosterone
- vasodilatory PGs: inc aldos
-increase renin due to: shunting blood so sympathetic; renal Na loss due to inc GFR; hCG
what does increased blood flow to in lead to
- inc skin temp, nail growth and hair growth
- disappearance of Raynaud’s syndrome
- nose bleeds, nasal stuffiness, snoring
what kidney changes to GFR occur in pregnancy
increase in GFR and effective renal plasma flow until 26 weeks, after which it decreases
what renal changes occur
- plasma conc decrease (urea and creatinine)
- glycosuria
- calciuria
- inc urinary freq
- urinary stasis due to dilation of collecting system
what pulmonary changes occur (i.e. breathing)
- inc tidal volume
- deep breathing (progesterone)
- RR unchanged
- expiratory reserve reduced
- lower pCO2, inc pO2, pH unchanged
- altered costal margin and diaphragm
what changes are involved in coagulation and fibrinolysis
- inc factors VII, VIII and X
- inc plasma fibrogen –> inc ESR (Erythrocyte sedimentation rate )
- dec. fibrinolytic activity
how does the GI tract change
- red. smooth muscle tone = lowered cardiac sphincter tone and lowered motility and mobility
- biliary stasis: inc, gastric reflux (heart burn), nutrient absorption and water reabsorption