Physiology of pregnancy

Question 1

Around which days, does the blastocyst attach to the lining of the uterus?

Answer 1

Days 5-8

Question 2

The blastocyst becomes completely buried in the uterine lining by which day?

Answer 2

Day 12

Question 3

The placenta is derived from which tissues?

Answer 3

Trophoblast and decidua

Question 4

The trophoblast cells (chorion) differentiate into what?

Answer 4

Syncytiotrophoblasts (multi-nucleated cells)

These invade the decidua and break down capillaries to form cavities filled with maternal blood

Question 5

By which week of pregnancy is the PLACENTA and foetal heart functional?

Answer 5

5th week of pregnancy

Question 6

Where does the embryo get its nutrition from in early development?

Answer 6

Trophoblastic cells (these invade decidua)

Progesterone stimulates decidual cells to concentrate glycogen, proteins and lipids

Question 7

HCG does what to corpus luteum?

Answer 7

Stops the corpus luteum from breaking down

(corpus luteum to continue secreting progesterone etc)

(progesterone stimulates decidual cells to concentrate glycogen, proteins and lipids)

Question 8

Which organ acts as a physiological arteriovenous shunt?

Answer 8

The placenta

circulation within the intervillous space acts partly as an ateriovenous shunt

Question 9

Which organ plays the role of the “fetal lungs”

Answer 9

The placentah

Question 10

The supply of the fetus with oxygen is facilitated by which 3 factors?

Answer 10

1) fetal Hb (increased ability to carry O2)
2) higher Hb concentration in fetal blood (50% more than adults)
3) Bohr effect (fetal Hb can carry more oxygen in low pCo2 than in high pCo2)

Question 11

How do fatty acids pass through placenta?

Answer 11

Free diffusion

Question 12

How does glucose pass through the placenta?

Answer 12

Simplified transport

Question 13

What is the fetus’s main source of energy? And which trimester is there a high need for this substance?

Answer 13

Glucose

high glucose need in 3rd trimester

Question 14

What is the trophoblast?

Answer 14

The surface layer of cells of the blastocyst

Question 15

What passes through the umbilical veins?

Answer 15

Oxygen saturated blood to fetus

Question 16

What passes through the uterine veins?

Answer 16

Oxygen poor blood (from fetus to mother)

Question 17

How are electrolytes transported across the placenta?

Answer 17

Electrolytes follow water (iron and calcium only go from mother to child)

Question 18

HCG effect on male fetus?

Answer 18

Development of sex organs

Question 19

When is human chorionic somatomammotropin produced in pregnancy?

Answer 19

Produced from week 5

Question 20

What does human chorionic somatomammotrophin do?

Answer 20

It has growth hormone like effects - protein tissue formation

• decreases insulin sensitivity in mother SO THERE IS MORE GLUCOSE FOR THE FETUS
• involved in breast development and possible lactation

Question 21

Which hormone is responsible for:

• development of decidual cells
• decreases uterus contractility
• preparation for lactation?

Answer 21

Progesterone

Question 22

Progesterone and decidual cells

Answer 22

Progesterone causes development of decidual cells

Question 23

Progesterone and uterus contractility?

Answer 23

Progesterone decreases uterus contractility

Question 24

Progesterone and lactation

Answer 24

Progesterone helps with preparation for lactation

Question 25

Which hormone causes: - enlargement of uterus - breast development - relaxation of ligaments?

Answer 25

Estrogen

Question 26

Which hormone is an indicator of the vitality of the fetus?

Answer 26

Estriol

Question 27

Estrogen and breasts?

Answer 27

Estrogen causes breast development

Question 28

Cardiac output and pregnancy?

Answer 28

Cardiac output increases (beginning week 6 and peaking around week 24) (decreases in the last 8 weeks as becomes sensitive to body position - uterus compresses vena cava)

Question 29

Iron requirements for 2nd half of pregnancy

Answer 29

6-7mg per day

Question 30

How do the following change in pregnancy: - plasma volume - erythropoesis (RBC) - Hb concentration

Answer 30

- Plasma volume increases proportionally with cardiac output (50%) - erythropoesis increases (25%) -although both are increasing, plasma volume increases more so Hb concentration is diluted (this decreases blood viscosity)

Question 31

Why do you get odema in pre-eclampsia?

Answer 31

Kidney function declines and you get salt and water retention (function probably declines because of high blood pressure or something)

Question 32

Is pre-eclampsia more common in women with a single baby or twins?

Answer 32

More common in multiple gestation (e.g. twins)

Question 33

Average weight gain in pregnancy?

Answer 33

24lbs (fetus - 5kg, mother -6kg)

Question 34

How many extra calories a day does the mother need?

Answer 34

250-300 extra calories

Question 35

How much extra protein does the mother need?

Answer 35

30g

Question 36

When is the mother's anabolic phase?

Answer 36

1st-20th week of pregnancy - anabolic metabolism of mother - quite small nutritional demands of the mother

Question 37

When does accelerated starvation of the mother occur? | catabolic phase

Answer 37

21-40th week of pregnancy (especially 3rd trimester) - high metabolic demands of fetus - accelerated starvation of mother

Question 38

Which hormones are responsible for insulin resistance in pregnancy?

Answer 38

HCS, cortisol and growth hormone

Question 39

Does the following occur in the anabolic or catabolic phase of pregnancy? - normal or increased sensitivity to insulin - lower plasmatic glucose level - lipogenesis, glycogen stores increases - growth of breasts, uterus,weight gain

Answer 39

Anabolic phase

Question 40

Does the following occur in the anabolic or catabolic phase of pregnancy? - maternal insulin resistance - increased transport of nutritients through placental membrane - lipolysis

Answer 40

Catabolic phase

Question 41

What iron supplement should the mother take?

Answer 41

300 mg ferrous sulfate

Question 42

Why does a mother need to take B vitamins?

Answer 42

Erythropoeisis

Question 43

What does folic acid (folate) help to protect against?

Answer 43

Neural tube defects

Question 44

When is vitamin K given and why?

Answer 44

Given right before giving birth - helps prevent intracranial bleeding during labour

Question 45

Estrogen and progesterone and their effects on contractility of the uterus?

Answer 45

- Estrogen increases contractility - Progesterone decreases contractility - The ratio of these alter just before giving birth

Question 46

Where is oxytocin produced?

Answer 46

Maternal posterior pituitary gland

Question 47

Oxytocin and contractility of uterus?

Answer 47

Oxytocin increases contractions and excitability

Question 48

Which hormones are responsible for controlling timing of labour?

Answer 48

Oxytocin Adrenal gland Prostaglandin

Question 49

What are braxton hicks contractions?

Answer 49

These are prodromal contractions (like practise ones) they start around week 6 of pregnancy but are not usually felt until 2nd/3rd trimester. They increase towards the end of pregnancy and eventually become real ones

Question 50

Growth of ductile system

Answer 50

Estrogen

Question 51

Development of lobule-alveolar system

Answer 51

Progesterone

Question 52

Estrogen and progesterone effects on milk production

Answer 52

Estrogen and progesterone inhibit milk production | at birth, estrogen and progesterone suddenly drop

Question 53

Two hormones needed for milk production

Answer 53

Prolactin | Oxytocin (produced by sucking stimulus)