Hormones, Pregnancy and Birth

Question 1

How long is Gestation period?

Answer 1

39 weeks, defined by day 1 from last period until birth

Question 2

What develops the amnion?

Answer 2

inner cell mass of the embryo

Question 3

What is the amnion?

Answer 3

Amniotic sac and amniotic fluid

Question 4

What is the function of the amniotic fluid?

Answer 4

maintains foetal temperature
provides lubrication for muscle, bone & digit movement and development
contribute to lung development
shock absorber

Question 5

How many stages are there in pregnancy?

Answer 5

3 trimesters

Question 6

When is the first trimester?

Answer 6

in the first 0-3 months

Question 7

What 3 major processes happen in the first trimester?

Answer 7

conception, implantation, embryogenesis

Question 8

What is the risk of miscarriage in the first trimester?

Answer 8

15%

Question 9

What happens in week 10 of pregnancy?

Answer 9

called a foetus (30mm) there is less risk of miscarriage

Question 10

WHen is the second trimester?

Answer 10

4 - 6.5 months

Question 11

What happens in the second trimester?

Answer 11

some foetuses open their eyes
movements in the uterus

Question 12

When is the third trimester?

Answer 12

6.5 - 9 months

Question 13

WHat happens in the third trimester?

Answer 13

major structures developed
growth period
fat is laid down
mass increase 3x and length 2x

Question 14

What is the 28 week premature baby survival rate?

Answer 14

90%

Question 15

What happens in weeks 28-33?

Answer 15

hearing developed

Question 16

What happens at 33 weeks?

Answer 16

mostly sleeping, mapping neurones

Question 17

What hormone is secreted by the embryo from 6 days old?

Answer 17

hCG - human chorionic gonadotrophin

Question 18

What is hCG secreted by? what does it do?

Answer 18

the chorion - maintains corpus luteum which secretes progesterone, maintaining endometrium

Question 19

What hormones are secreted by the corpus luteum?

Answer 19

oestrogen and progesterone

Question 20

What hormones are secreted by the placenta?

Answer 20

oestrogen and progesterone

Question 21

What do the oestrogen and progesterone secretion by corpus luteum and placenta do?

Answer 21

inhibits FSH (no follicles)
inhibits LH (no ovulation)
inhibits prolactin (no milk made)

Question 22

WHat does progesterone inhibit in pregnancy?

Answer 22

oxytocin, neither myometrium no milk ducts will contract

Question 23

What does oestrogen stimulate during pregnancy?

Answer 23

stimulates uterus and mammary gland growth

Question 24

What are produced by the foetal adrenal glands for what purpose?

Answer 24

Corticosteroids are produced in response to the mother’s immune system ‘attacking’ the foetal tissues

Question 25

What do mature foetal lungs secrete?

Answer 25

prostaglandins

Question 26

What do cortiscosteroids and prostaglandins decrease? allowing what?

Answer 26

decrease maternal progesterone, allowing oxytocin and prolactin to be secreted by the mother?

Question 27

What is oxytocin secreted from?

Answer 27

secreted from maternal posterior pituitary gland

Question 28

What is the function of oxytocin?

Answer 28

causes myometrial contractions via positive feedback giving birth/labour

Question 29

What is prolactin secreted from?

Answer 29

by maternal anterior pituitary gland

Question 30

What is the function of prolactin?

Answer 30

causes milk production from mammary glands

Question 31

What reflex causes release of oxytocin?

Answer 31

suckling reflex, which causes muscles around milk ducts to contract and release milk