Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Reproductive System > Foetal Physiology And Growth > Flashcards

Foetal Physiology And Growth Flashcards

1
Q

Where are the foetal exchange capillaries located?

A

Within the chorionic villi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the only diffusion barrier layers of placenta left by term?

A

Syncytiotrophoblast

Foetal capillary wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the approximate ppO2 of foetal blood?

A

4 kPa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What factors increase foetal oxygen content?

A

HbF - optimised for hypoxic environment

Foetal haematocrit greater than adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What promotes oxygen exchange to foetus at the placenta?

A

Increase maternal 2,3-BPG, decreased affinity of maternal Hb for oxygen
Gradient - lower foetal ppO2
CO2 loss from foetus, pH rise in foetal blood, increasing affinity of HbF for oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the subunits of HbF?

A

2 alpha

2 gamma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why is there a decreased ppCO2 in maternal blood and why is this useful?

A

Progesterone driven hyperventilation causes blow off more CO2
Conc gradient of CO2 favours CO2 leaving the foetus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which duct allows blood to bypass the liver?

A

Ductus venosus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why must we bypass the liver in a foetus?

A

Need to maintain the oxygen saturation for the rest of body

Liver very metabolically active so if passed through first the blood would lose lots of oxygen and nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the foramen ovale in a foetus

A

Shunt from RA to LA as pressure greater in RA

2 leaves of atrial septum forced apart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the crista dividens?

A

Crest on free border of septum secundum

Small specialisation that optimises flow to LA in order to get blood to the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why must some blood enter the RV in the foetus?

A

RV needs pressure to push against in order to develop muscle
And lungs require a small amount of blood to develop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the role of ductus arteriosus?

A

Shunts blood from the pulmonary trunk to the aorta

Minimises the drop to oxygen saturation (esp to the brain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the foetal response to hypoxia?

A

Foetal chemoreceptors detect decreased ppO2
Foetal HR slows to reduce oxygen demand
Bradycardia (vagus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which women are most likely to cause chronic hypoxaemia in their babies?

A

Women who smoke during pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the consequences of chronic hypoxaemia to foetus?

A

Growth restriction

Behavioural changes eg. Less movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the critical hormones for foetal growth and when are they most abundant?

A

IGF I - T2 and T3 (nutrient dependent)

IGF II - T1 (nutrient independent)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the functions of the amniotic sac?

A

Protection

Bathe lungs for development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the volume of amniotic fluid at 8 weeks?

A

10 ml

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the volume of amniotic fluid by 38 weeks?

A

1 litre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Urine production of foetus begins at …

A

9 weeks gestation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Approximately how much urine does a foetus produce per day in T3?

A

Up to 800 ml

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the composition of amniotic fluid

A

98% water

Electrolytes, creatinine, urea, bile pigments, renin, glucose, hormones, foetal cells

24
Q

What is vernix caseosa?

A

Waterproofing of the foetal skin

Prevent damage to skin during extended exposure to AF

25
Q

What is meconium?

A

First poo of the baby
Debris accumulated in the gut with bile = green
Should always be passed after delivery

26
Q

Why is it a problem if the meconium is released before birth?

A

Indicates foetal distress

May inhale it - cause respiratory distress

27
Q

What is amniocentesis?

A

Sampling of AF
Allows for cool action of foetal cells
Useful diagnostic test eg. Karyotyping

28
Q

Can a foetus conjugate bilirubin?

A

No

29
Q

What weeks mark the different stages of development?

A

1-2 pre-embryonic
3-8 embryonic
9-38 foetal

30
Q

How do we calculate pregnancy weeks?

A

From first day of last menstrual period
Conception weeks + 2
Term = 40 weeks

31
Q

When is the head approximately half CRL?

A

At 9 weeks

32
Q

At term, how big is the head relative to the whole body length?

A

1/4

33
Q

Why do we use USS at antenatal assessment?

A

Safe
Used in early pregnancy to calculate age and rule out ectopic
Carried out at 20 weeks
Estimate growth and look for anomalies

34
Q

When is the crown-rump length most accurate?

A

Between 7 and 13 weeks

35
Q

What is the biparietal diameter?

A

Distance between 2 parietal bones of foetal skull

Helping to date pregnancies in T2 and T3

36
Q

Other than BPD, what else can be used for dating foetuses?

A

Abdominal circumference

Femur length

37
Q

What is the average birth weight?

A

3.5 kg = 7.7lb

38
Q

Under what weight suggests growth restriction?

A

< 2.5 kg

< 5.5 lb

39
Q

Over what weight is macrosomia?

A

> 4.5 kg

> 9.9 lb

40
Q

What are some reasons for low birth weight?

A

Premature
Constitutionally small
Growth restriction

41
Q

When does the functional specialisation of the lungs occur?

A

Foetal period

42
Q

What is occurring between weeks 8 - 16 in the respiratory system?

A

Pseudoglandular stage

Duct system begins to form within bronchopulmonary segments

43
Q

What happens between weeks 16 - 26 in the respiratory system?

A

Canalicular stage
Formation of respiratory bronchioles - further branching
Budding from bronchioles
Still no gas exchange membrane

44
Q

What happens between week 26 and term in the respiratory system?

A

Terminal sac stage
Terminal sacs bud from resp bronchioles
Membranes for gas exchange
Differentiation of Type 1 and 2 pneumocytes

45
Q

Why does the foetus undergo practice breathing movements?

A

Conditioning of the respiratory musculature

Diaphragm and intercostals

46
Q

What does the amniotic fluid in the lungs do?

A

Growth factors in the fluid

Encourages type 1 and 2 differentiation

47
Q

What is the threshold of viability of a foetus?

A

~ 24 weeks +

48
Q

Describe respiratory distress syndrome

A

Often affects premature babies
Insufficient surfactant
If unavoidable then give mother glucocorticoids

49
Q

What is the foetal heart rate?

A

110 - 140 bpm

50
Q

When is a definitive foetal HR achieved?

A

Week 15

51
Q

What clinical sign would ensue with absent foetal kidney function?

A

Oligohydramnios

52
Q

What might cause polyhydramnios?

A

Foetal inability to swallow - structural or neurological

53
Q

When do corticospinal tracts begin to form and what are they for?

A

4th month

For coordinated voluntary movement

54
Q

When does myelination of the brain begin?

A

9th month

55
Q

There is no moment in a foetus until …

A

Week 8

56
Q

What is quickening?

A

Maternal awareness of foetal movements
Around 17 weeks
(May be earlier in subsequent pregnancies)

57
Q

When do gyri and sulci appear in the brain?

A

~ 28 weeks

Reproductive System (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions