Fetal Development and Adaptation to Extra-Uterine Life Flashcards
```Before birth the baby “breathes”
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How does the lung develop in late pregnancy?
During REM the diaphragm distends stimulating their growth. Surfactant is produced reducing surface tension stimulated by cortisol
Surfactant needed for first breath
Respiratory distress syndrome in premies are given this
What can be given to premature babies to cause lung development?
Glucorticoids
When do functioning lungs really develop?
35ish weeks
What happens to liver glycogen when cortisol rises?
It goes down so the baby is saving some for energy
What do fetal circulation - shunts do?
Incorporates the placenta into fetal circulation and insures appropraite delivary of oxygenated blood and nutrients
What the umbilical arteries take blood to? and what does the vein do?
The body to the placenta and the vein takes deoxygenated blood from placenta to body
There is 3 of these
What are the shunts?
Ductus Venosus
Ductus Ateriosus
Foramen Ovale
What does the Ductus Venosus do?
Shunts oxygenated blood from placenta away from the semifunctioning liver and to the heart.
Shunt 1
What does the Ductus Ateriosus do?
Connects the aorta with the pulmonary artery shunting blood away from lungs and to the aorta
Shunt 3
What does the Foramen Ovale do?
allows oxygenated blood in the right atrium to reach the left atrium
This can cause a hole in the heart and is split into 2 streams.
Shunt 2
How would you get back to our circulation?
The adult human circulation instead of the fetal circulation
Shut the shunts
Protaglandin E2, cortisol, BP
How is the fetal cardiovascular system matured?
Prostaglandin E2 maintina patent ductus arteriosus
Cortisol increases cardiac output and peripheral resistance
Increase in blood pressure
what is the first thing which happens as the fetus transitions to adult circulation?
When born the baby takes a deep breath decreasing the vascular resistance letting blood into lung easily. You also lose the umbilical circulaton and the three shunts close.
R and L side of heart, DA shunt involvement/ stimulation
What happens second in the transition from fetal circulation to adult circulation?
Drop in pressure of R side of heart and a rise on the L side of heart creating a transient reversal of flow through the Ductus Arteriole (DA) and the high pO2 stimulates the DA to contract
What is the third thing that happens when changing from fetal to adult circulation?
DA constriction inhibited by low pO2 and high PGE2
Foreman Olvale (FO) valve with reversal pressure in the atria pushes against wall separating both sides of the heart
What adult diseases can come from fetal programming and how is this caused?
Can lead to chronic diseases in childhood for example, raised stress response, CVD’s, obesity and diabetes.
Can be caused from interuterine insult e.g. hypocia, nutrition, prenatal stress, glucorticoids and smking
What is being researched in terms of resistance in utero?
Insulin, leptin and glucorticoids
Can some stress be good for babies?
Yes - such as stress from a normal birth rather than a caesarean section
What is the barker hypothesis?
low birth weight can increase the risk of coronary heart disease
What did the Dutch famine show?
What happened to fetus’ in early pregnancy vs mid pregnancy and both
Fetuses in early pregnancy during the dutch famine where more likely to get coronary heart disease, increased obesity, altered clotting, atherogenic lipid profile. Increased amount of people reporting poor health
If you were mid gestation the baby would be more likely to have obstructive airway disease
And in any stage decreased glucose tolerance and improved fertility was seen
