Physiology of Motherhood Flashcards Preview

BI0005 > Physiology of Motherhood > Flashcards

Flashcards in Physiology of Motherhood Deck (77):
1

What are the two parts of the uterus

Endometrium and myometrium

2

Describe the endometrium

Inner layer has good blood supply. Is the maternal contribution to the placenta

3

Describe the myometrium

Muscle layer, no contractions during pregnancy, contractions for labour

4

What is partuition

Labour, delivery of the baby, placenta and associated membranes

5

What initiates paruition

Chemical and physical factors

6

What is parturition physically associated with

Regular, painful uterine contractions

7

What is parturition physiologically associated with

Cervical ripening- cervix softens, shortens and dilates

8

Where do contractions occur

In the myometrium

9

What inhibits contractions during pregnancy

Progesterone

10

What type of muscles are used for contractions

Smooth muscles (involuntary control)

11

What happens in the last few weeks of pregnancy in terms of contractions

Braxton-Hicks practice contractions. They are painless and last a few seconds

12

Why do Braxton-Hicks contractions occur

Due to increased levels of oestrogen

13

How is parturition initiated

Complex interplay of local regulators, hormones and physical factors.

14

What are the physical factors associated with the initiation of parturition

Progressive stretching of the myometrium and placental insufficiency

15

What does progressive stretching of the myometrium result in

It becomes thinner and increases in excitability. At a critical level of excitability spontaneous contractions occur which squeeze the foetus towards the cervix.

16

What does placental "insufficiency" result in

The placenta is no longer able to provide sufficient nutrients and oxygen. Foetal capillaries in the placenta are blocked with blood clots and debris

17

What is involved in the chemical initiation of parturition

Hormone levels (in mother and foetus) and possibly other bioactive factors

18

What are the 4 hormone initiators of labour

Less progesterone. More oestrogen, prostaglandins and oxytocin

19

Which two chemical stimulate the release of oestrogen

Corticotropin-releasing hormone (CRH) and cortisol

20

Where is CRH secreted from and how does it increase oestrogen levels

It is released from the placenta and pituitary gland and releases oestrogen building blocks

21

Where is cortisol secreted from and how does it increase oestrogen levels

Secreted from foetal adrenal gland. Increases the oestrogen: progesterone ratio. It removes the inhibitory effect of progesterone on the myometrium

22

What happens to oestrogen levels towards the end of pregnancy

There is a large increase

23

What does the increase in oestrogen levels do

Increases the sensitivity of the uterus to contractile stimuli, increases the number of receptors for oxytocin in the uterus. Stimulates the release of prostaglandins

24

Where is oxytocin produced

In the posterior pituitary gland of the mother and foetus

25

What does oxytocin do

Stimulates powerful contractions of the uterus and stimulates the production of prostaglandins during pregnancy.

26

What does oxytocin do following delivery

It reduced blood loss

27

What are prostaglandins synthesised by

The placenta and myometrium

28

What can prostaglandins be used for

Inducing labour

29

What do prostaglandins do

Enhance contractions. One way is by releasing the calcium required for contractions

30

What happens to the baby before labour can begin

The baby has rotated, dropped low in the pelvis and head has "engaged" with the cervix. Results in stretching of the cervix

31

What does stretching of the cervix result in

Stretch receptors send messages to release oxytocin

32

What are the 3 stages of labour

1. Dilation
2. Explusion
3. Placental

33

How long does dilation last

6-12 hours

34

When does dilation occur

From the onset of labour until full cervical dilation (10cm)

35

What happens during dilation

Opening up and thinning of the cervix. The cervix stretches around the engaged head. Uterine contractions increase in strength and frequency.

36

How long does explusion last

Minutes-hours
Usually less than 2 hours

37

When does explusion occur

Time from full cervical dilation until birth

38

What does the baby do during expulsion

Rotate to make birth easier

39

What happens during explusion

Continuous strong contractions force the foetus down and out of the uterus and vagina. Contractions alone are sufficient for delivery yet sometimes need to push

40

What happens to blood flow in the umbilical chord after birth

Blood continues to pass for a short time until blood pressure drops and blood flow stops

41

When can you cut the umbilical chord and why

Only once blood flow has stopped as useful nutrients is passed to the baby during this short time

42

How long does placental last

5-30 minutes

43

When does placental occur

From birth until delivery of the placenta

44

What happens during placental

Powerful contractions result in: explusion of placenta and membranes and closure of uterine blood vessels to reduce blood loss

45

What is lactation

Supply of milk to feed baby

46

Where is milk supplied from

The mammary glands

47

What happens to the mammary glands during pregnancy

Hormone induced changes occur

48

What stimulates the delivery of milk

Part hormonal part suckling

49

What is initially secreted from the breasts

Colostrum

50

Why do the breasts enlarge during pregnancy

Ducts proliferate, increasing in cell number and secretion. Fat is deposited between the lobules

51

Which hormones stimulate milk production

Combination of progesterone, oestrogen and placental lactogen

52

Why is milk production inhibited during pregnancy

Due to high levels of oestrogen and progesterone. Both decrease at birth

53

What hormone is secreted after birth

Prolactin

54

What is milk production stimulated by

A rise in prolactin and oxytocin

55

What further stimulates prolactin and oxytocin

Suckling

56

Where is prolactin secreted from

The anterior pituitary gland

57

What is the function of prolactin

Stimulates milk-producing epithelial cells

58

What is needed to maintain milk production

High levels of prolactin

59

Where is oxytocin secreted from

The posterior pituitary gland

60

What is the function of oxytocin

It stimulates milk ejecting epithelial cells

61

Describe the milk production and ejection reflex

Suckling -> sensory input -> hypothalamus ->
a.) posterior pituitary -> oxytocin -> milk ejection
b.) anterior pituitary -> prolactin -> milk production

62

When does lactation end

2-3 weeks after weaning

63

How long it's colostrum present for

Until day 4

64

What is colostrum

A yellow fluid

65

What is the composition of colostrum

High in protein, low in fat, rich in immune molecules especially IgA, rich in some vitamins: A, D, E, K, rich in mnerals

66

What is the main source of energy in milk

Fat

67

What sugar is contained in milk

Lactose in high levels

68

What protein is contained in milk

Casein

69

What is found in milk apart from protein, sugar and fat

Calcium, minerals and vitamins

70

Which cells that fight against infection are found in breast milk

White blood cells

71

Which molecules are found in breast milk

IgA antibody, interferon and lysozyme

72

What properties do interferon and lysozyme have

They are antibacterial

73

What affect does breast feeding have on the infant later in life

Slight reduction in lymphoma, heart disease, allergies, respiratory and GI infections

74

What affect does breastfeeding have on mother

Protects against osteoporosis and breast cancer

75

How much milk does a baby weight 5-6kg consume a day

0.8-1 litre

76

How many calories does each litre of milk contain

750

77

What effect does the high calorie content of breast milk have on the mother

She needs extra nutrient in take, especially calcium and phosphate