1: Perinatal Adaptation I Flashcards Preview

Reproduction Week 5 2018/19 > 1: Perinatal Adaptation I > Flashcards

Flashcards in 1: Perinatal Adaptation I Deck (60)
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1

What colour are babies when they're born?

Why?

Blue (cyanotic)

Hypoxic, deflated lungs

2

Swallowing amniotic fluid is a normal part of foetal homeostasis.

What condition can be caused by swallowing amniotic fluid following or during foetal distress?

Meconium aspiration syndrome

causes ARDS - meconium clogs up air spaces and neonate will become hypoxic

3

At what point in gestation do the alveoli develop?

36 weeks

So prematurity requires steroids to speed up lung development

4

What is produced from 26 weeks and is required for lung development?

Pulmonary surfactant

5

What is the purpose of pulmonary surfactant?

Which cells produce it?

Reduce alveolar surface tension, allowing them to resist collapse

Type II pneumocytes

6

What does amniotic fluid consist of

a) early in the pregnancy

b) later in the pregnancy?

a) Maternal fluid

b) Foetal urine

7

A lack of amniotic fluid in the womb is related to a problem with which organs?

Kidneys

involved in amniotic fluid recycling

8

Which organs allow a baby to swallow and then filter amniotic fluid?

Kidneys

9

Why do babies cry when they are born?

Forcing air against a closed glottis pushes fluid from the air spaces to the interstitium

10

Which maternal antibody is passed across the placenta to the foetus?

IgG

11

In the first 10 - 20 minutes of life, is oxygen used to resuscitate babies?

No

Does more harm than good

12

How long should you wait before clamping a newborn's umbilical cord?

Why?

3 - 5 minutes

Allows adequate transfer of blood - clamping too early can lead to hypovolaemia and anaemia

13

What are the three shunts in the foetal circulation?

Ductus venosus (bypassing the liver)

Foramen ovale (right to left shunt in the heart)

Ductus arteriosus (bypassing pulmonary circulation)

14

In the foetus, the pulmonary circulation has a (high / low) resistance.

high resistance

15

Does blood travel to the lungs in the foetus?

Yes

But a v small amount (around 7%), most of it is shunted from R heart to L heart

16

How many umbilical arteries and veins does a foetus have?

Which type of blood travels in each?

1x umbilical vein - OXYGENATED BLOOD FROM MOTHER

2x umbilical arteries - DEOXYGENATED BLOOD FROM FOETUS

17

Describe the pulmonary vascular resistance before birth.

High

Allows very little blood to travel to the lungs

18

Describe the systemic vascular resistance before birth.

Low

Especially compared to the pulmonary resistance

Addition of placenta adds a massive 'length' to vasculature, reducing the resistance

19

What remnants of the

a) ductus venosus

b) foramen ovale

c) ductus arteriosus

can be found in adults?

a) Ligamentum teres of the liver

b) Oval fossa

c) Ligamentum arteriosum

20

Why does the foramen ovale close after birth?

Pulmonary vascular resistance drops, so blood goes to the lungs avoiding the shunt

Systemic vascular resistance increases, so it's harder to shunt blood from right heart to left heart

L pressure holds the valve shut and over time it fuses with the septum

21

What three factors contribute to the closing of the ductus arteriosus?

1. Reduced blood flow

2. Reduced Prostaglandin E2 produced by placenta

3. Smooth muscle CONTRACTS (unique response not found anywhere else)

22

After birth, the smooth muscle of the ductus arteriosus (relaxes / constricts).

constricts to reduce blood flow through shunt

23

Which chemical maintains the patency of the ductus arteriosus?

Which organ produces it?

Prostaglandin E2

Placenta

24

Why does systemic vascular resistance decrease following birth?

Widespread vasodilation caused by oxygen

Loss of the 'length' of the placental circulation

25

Why does pulmonary vascular resistance drop following birth?

Lungs inflate

Oxygen is a vasodilator --> widespread vasodilation of the pulmonary vasculature

26

Which form of glucose is stored by the foetus before birth?

What is the advantage of this?

Glycogen

Loads of sugar stored for first few days post-natally

27

Which type of fat can be rapidly oxidised to produce energy?

Brown fat

28

Which process is brown fat useful for?

Thermogeneration

making heat

29

What is the function of

a) white fat

b) brown fat?

a) Energy storage

b) Thermogeneration

30

Where is brown fat found in the foetus?

Between scapulae

Around viscera