From fetus to neonate Flashcards
What is the role of progesterone?
- inhibit uterine contractions - prevents fetal expulsion
- promotes cervical plug - provides microbial barrier
What is the role of oestrogen?
- promotes connexin insertion between myometrial cells
- stimulates oxytocin receptor insertion into myometrium
- increases prostaglandin (PGE2) production
What is the role of cortisol production in pregnancy from the mother and fetus?
helps lung maturation
Where is corticotropin releasing hormone produced and where does it act?
produced in the placenta and acts on the anterior pituitary gland in the mother and fetus
What is the role of the adrenal cortex in the fetus?
releases DHEA which leads to the production of oestrogen
What does a sudden surge in CRH mean?
could act as one of the triggers for the onset of labour
What causes the onset of labour?
either an increase in CRH and/or decrease in progesterone
What is the role of oxytocin in labour?
oxytocin increases uterine contractions in a positive feedback loop
also stimulates contraction directly and indirectly via PGF2 alpha
What are prostaglandins?
“local hormones” for cell signaling
- short-lived and have multiple actions in labour/delivery
- PGE2 relaxes cervix
- PGF2 alpha contracts uterus
What is the 2nd stage of labour?
delivery of fetus
combination of uterine contraction and maternal effort
What happens in the 3rd stage of delivery?
delivery of placenta after shearing off
uterine contraction compress vessels to produce haemostasis
Which hormones stimulate surfactant production?
cortisol
thyroxine
prolactin
What happens to fetal lungs at the onset of labour?
hormones decrease fetal lung fluid production and start active reabsorption
What is compliance?
the ease with which something can be stretched
What is surface tension?
the tendency of liquid surface to pull together by molecular forces
