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Flashcards in Human Reproduction Deck (59)
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31

When are the placenta and foetal heart functional?

by week 5

32

What hormones maintain during the 1st trimester?

hCG - produced by blastocyst

33

What is the function of hCG?

maintains corpus luteum and thus progesterone and oestrogen until week 10

34

What is the function of hCG?

maintains corpus luteum and thus progesterone and oestrogen until week 10

35

Why does oestrogen not come from the placenta initially?

the placenta does not posses DHEA from the feotal adrenal cortex to convert progesterone to oestrogen at first

36

What is the role of oestrogen in pregnancy?

stimulates growth of myometrium musculature
stimulate development of mammary gland ducts

37

What is the role of progesterone in pregnancy?

suppresses contraction of uterine myometrium
promotes formation of mucus plug
stimulate development of mammary milk glands

38

What are the physical changes the mother undergoes?

enlargement of uterus and placenta
enlargement of breasts
increase blood vol
weight gain
increase ventilation
increase GFR
increased nutritional requirements

39

Why does the blood vol increase?

oestrogen stimulates angiotensin and renin secretion which results in aldosterone which retains Na and water

40

What are the endocrine secretions of the placenta?

hCG
oestrogen and progesterone
hCS
PTH-related peptide
Relaxin
Placental CRH

41

What is the function of hCS?

decreases maternal blood glucose use, increases plasma FA
prepares breasts for lactation

42

What is the function of pTH-rp?

mobilises maternal Ca for calcification of foetal bones

43

What is the function of relaxin?

softens cervix, loosens pelvic connective tissue

44

What is the function of placental CRH?

stimulates DHEA production by fetal adrenal cortex, important for initiating partuition

45

What does partuition require?

dilation of cervical canal
contractions of uterine myometrium

46

What happens in preparation of partuition?

Braxton-hicks
softening of cervix - relaxin and prostaglandins - breaks down cervical collagen fibres
relaxation of pelvic bones - relaxin
foetus drops

47

What appears to initiate labour?

increased oxytocin receptors triggered by increase estrogen and prostaglandins which increases uterine contraction

48

What happens in the first stage of labour?

cervix dilates
rupture of amniotic sac

49

What happens during the second stage of labour?

delivery of baby by uterine and abdominal contractions

50

What happens during the third stage of labour?

delivery of placenta

51

What is involution?

shrinkage of uterus to pre-pregnancy size
lochia

52

What is involution induced by?

fall in oestrogens and progesterone
oxytocine released in response to breast feeding

53

What do breast ducts terminate in?

lobules made of milk producing glands

54

What triggers development of the breast?

increased oestrogen (duct) and progesterone (lobule)
prolactin - enzymes that produce milk

55

What does suckling trigger?

neuroendocrine reflex -> prolactin and oxytocin

56

What are the roles of prolactin and oxytocin in breast feeding?

prolactin - milk production
oxytocin - milk ejection

57

What is the role of oxytocin in gestation and post-partum?

stimulates contraction of myoepithelial cells
hastens involution
suppresses LH and FSH and thus menstrual cycle

58

What are the components of breast milk?

water, particles isotonic with plasma, lactose, lipids, vitamins, minerals, immunoprotective agents, other proteins including immunoglobulins

59

How many calories does breast milk have per L?

600-750kcal