Hormones, Pregnancy and Birth Flashcards
How long is Gestation period?
39 weeks, defined by day 1 from last period until birth
What develops the amnion?
inner cell mass of the embryo
What is the amnion?
Amniotic sac and amniotic fluid
What is the function of the amniotic fluid?
maintains foetal temperature
provides lubrication for muscle, bone & digit movement and development
contribute to lung development
shock absorber
How many stages are there in pregnancy?
3 trimesters
When is the first trimester?
in the first 0-3 months
What 3 major processes happen in the first trimester?
conception, implantation, embryogenesis
What is the risk of miscarriage in the first trimester?
15%
What happens in week 10 of pregnancy?
called a foetus (30mm) there is less risk of miscarriage
WHen is the second trimester?
4 - 6.5 months
What happens in the second trimester?
some foetuses open their eyes
movements in the uterus
When is the third trimester?
6.5 - 9 months
WHat happens in the third trimester?
major structures developed
growth period
fat is laid down
mass increase 3x and length 2x
What is the 28 week premature baby survival rate?
90%
What happens in weeks 28-33?
hearing developed
What happens at 33 weeks?
mostly sleeping, mapping neurones
What hormone is secreted by the embryo from 6 days old?
hCG - human chorionic gonadotrophin
What is hCG secreted by? what does it do?
the chorion - maintains corpus luteum which secretes progesterone, maintaining endometrium
What hormones are secreted by the corpus luteum?
oestrogen and progesterone
What hormones are secreted by the placenta?
oestrogen and progesterone
What do the oestrogen and progesterone secretion by corpus luteum and placenta do?
inhibits FSH (no follicles)
inhibits LH (no ovulation)
inhibits prolactin (no milk made)
WHat does progesterone inhibit in pregnancy?
oxytocin, neither myometrium no milk ducts will contract
What does oestrogen stimulate during pregnancy?
stimulates uterus and mammary gland growth
What are produced by the foetal adrenal glands for what purpose?
Corticosteroids are produced in response to the mother’s immune system ‘attacking’ the foetal tissues
What do mature foetal lungs secrete?
prostaglandins
What do cortiscosteroids and prostaglandins decrease? allowing what?
decrease maternal progesterone, allowing oxytocin and prolactin to be secreted by the mother?
What is oxytocin secreted from?
secreted from maternal posterior pituitary gland
What is the function of oxytocin?
causes myometrial contractions via positive feedback giving birth/labour
What is prolactin secreted from?
by maternal anterior pituitary gland
What is the function of prolactin?
causes milk production from mammary glands
What reflex causes release of oxytocin?
suckling reflex, which causes muscles around milk ducts to contract and release milk
