Physiology of Motherhood

Question 1

What are the two parts of the uterus

Answer 1

Endometrium and myometrium

Question 2

Describe the endometrium

Answer 2

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

Question 3

Describe the myometrium

Answer 3

Muscle layer, no contractions during pregnancy, contractions for labour

Question 4

What is partuition

Answer 4

Labour, delivery of the baby, placenta and associated membranes

Question 5

What initiates paruition

Answer 5

Chemical and physical factors

Question 6

What is parturition physically associated with

Answer 6

Regular, painful uterine contractions

Question 7

What is parturition physiologically associated with

Answer 7

Cervical ripening- cervix softens, shortens and dilates

Question 8

Where do contractions occur

Answer 8

In the myometrium

Question 9

What inhibits contractions during pregnancy

Answer 9

Progesterone

Question 10

What type of muscles are used for contractions

Answer 10

Smooth muscles (involuntary control)

Question 11

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

Answer 11

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

Question 12

Why do Braxton-Hicks contractions occur

Answer 12

Due to increased levels of oestrogen

Question 13

How is parturition initiated

Answer 13

Complex interplay of local regulators, hormones and physical factors.

Question 14

What are the physical factors associated with the initiation of parturition

Answer 14

Progressive stretching of the myometrium and placental insufficiency

Question 15

What does progressive stretching of the myometrium result in

Answer 15

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

Question 16

What does placental “insufficiency” result in

Answer 16

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

Question 17

What is involved in the chemical initiation of parturition

Answer 17

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

Question 18

What are the 4 hormone initiators of labour

Answer 18

Less progesterone. More oestrogen, prostaglandins and oxytocin

Question 19

Which two chemical stimulate the release of oestrogen

Answer 19

Corticotropin-releasing hormone (CRH) and cortisol

Question 20

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

Answer 20

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

Question 21

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

Answer 21

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

Question 22

What happens to oestrogen levels towards the end of pregnancy

Answer 22

There is a large increase

Question 23

What does the increase in oestrogen levels do

Answer 23

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

Question 24

Where is oxytocin produced

Answer 24

In the posterior pituitary gland of the mother and foetus

Question 25

What does oxytocin do

Answer 25

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

Question 26

What does oxytocin do following delivery

Answer 26

It reduced blood loss

Question 27

What are prostaglandins synthesised by

Answer 27

The placenta and myometrium

Question 28

What can prostaglandins be used for

Answer 28

Inducing labour

Question 29

What do prostaglandins do

Answer 29

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

Question 30

What happens to the baby before labour can begin

Answer 30

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

Question 31

What does stretching of the cervix result in

Answer 31

Stretch receptors send messages to release oxytocin

Question 32

What are the 3 stages of labour

Answer 32

1. Dilation 2. Explusion 3. Placental

Question 33

How long does dilation last

Answer 33

6-12 hours

Question 34

When does dilation occur

Answer 34

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

Question 35

What happens during dilation

Answer 35

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

Question 36

How long does explusion last

Answer 36

Minutes-hours | Usually less than 2 hours

Question 37

When does explusion occur

Answer 37

Time from full cervical dilation until birth

Question 38

What does the baby do during expulsion

Answer 38

Rotate to make birth easier

Question 39

What happens during explusion

Answer 39

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

Question 40

What happens to blood flow in the umbilical chord after birth

Answer 40

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

Question 41

When can you cut the umbilical chord and why

Answer 41

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

Question 42

How long does placental last

Answer 42

5-30 minutes

Question 43

When does placental occur

Answer 43

From birth until delivery of the placenta

Question 44

What happens during placental

Answer 44

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

Question 45

What is lactation

Answer 45

Supply of milk to feed baby

Question 46

Where is milk supplied from

Answer 46

The mammary glands

Question 47

What happens to the mammary glands during pregnancy

Answer 47

Hormone induced changes occur

Question 48

What stimulates the delivery of milk

Answer 48

Part hormonal part suckling

Question 49

What is initially secreted from the breasts

Answer 49

Colostrum

Question 50

Why do the breasts enlarge during pregnancy

Answer 50

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

Question 51

Which hormones stimulate milk production

Answer 51

Combination of progesterone, oestrogen and placental lactogen

Question 52

Why is milk production inhibited during pregnancy

Answer 52

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

Question 53

What hormone is secreted after birth

Answer 53

Prolactin

Question 54

What is milk production stimulated by

Answer 54

A rise in prolactin and oxytocin

Question 55

What further stimulates prolactin and oxytocin

Answer 55

Suckling

Question 56

Where is prolactin secreted from

Answer 56

The anterior pituitary gland

Question 57

What is the function of prolactin

Answer 57

Stimulates milk-producing epithelial cells

Question 58

What is needed to maintain milk production

Answer 58

High levels of prolactin

Question 59

Where is oxytocin secreted from

Answer 59

The posterior pituitary gland

Question 60

What is the function of oxytocin

Answer 60

It stimulates milk ejecting epithelial cells

Question 61

Describe the milk production and ejection reflex

Answer 61

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

Question 62

When does lactation end

Answer 62

2-3 weeks after weaning

Question 63

How long it's colostrum present for

Answer 63

Until day 4

Question 64

What is colostrum

Answer 64

A yellow fluid

Question 65

What is the composition of colostrum

Answer 65

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

Question 66

What is the main source of energy in milk

Answer 66

Fat

Question 67

What sugar is contained in milk

Answer 67

Lactose in high levels

Question 68

What protein is contained in milk

Answer 68

Casein

Question 69

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

Answer 69

Calcium, minerals and vitamins

Question 70

Which cells that fight against infection are found in breast milk

Answer 70

White blood cells

Question 71

Which molecules are found in breast milk

Answer 71

IgA antibody, interferon and lysozyme

Question 72

What properties do interferon and lysozyme have

Answer 72

They are antibacterial

Question 73

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

Answer 73

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

Question 74

What affect does breastfeeding have on mother

Answer 74

Protects against osteoporosis and breast cancer

Question 75

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

Answer 75

0.8-1 litre

Question 76

How many calories does each litre of milk contain

Answer 76

750

Question 77

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

Answer 77

She needs extra nutrient in take, especially calcium and phosphate