From foetus to neonate Flashcards
Describe the state of a feotus
Cushioned by amniotic fluid
Protected from truama, cold and infection
Lungs full of fluid
Placental transfer of oxygen, Co2, continuous nutrition through placenta
Elimination of waste products through placenta
Describe the state of a week old neonate
Efficient respiration through lungs Maintains own temp Feeding orally Eliminating bilirubin and urea Acquiring intestinal microfloa and making immune response
Function of a babies first gasp for air
Draws air into lungs
Active clearance of lung fluid
Establishes functional residual capacity in lungs
Why do babies cry when they’re born
High expiratory pressure with crying aids formation of functional residual capacity
How can absorption of lung fluid be induced?
Cathecholamines
Function of surfactant?
Reduces surface tension on the interphase between alveolar air and fluid, preventing collapse of alvolear
What makes up surfactant
CPPC and phosphatidylglycerol
Stabilised by protein B
Blood supply of umbilical cord?
1 vein
2 arteries
What do arteries in umbilical cord carry?
Oxygenated blood
What is the result of increased oxygen levels in alveoli and pulmonary capillary during birth?
Drop of pulmonary vascular resistance and smooth muscle relaxation
Increased pulmonary artery blood flow
Reversal of shunt across foramen ovale and ductus arteriosus
How does the foetus prepare for birth?
Accumulation of fat and glycogen
Secretion of surfactant
Inhibition of foetal breathing during labour
Switch from secretion to absorption of fluid in lungs
What are glycogen stores limited to in full term baby?
34g
Why is neonatal jaundice so common?
Breakdown of red cell mass after birth
Bilirubin formed from breakdown of haem
Immaturity of glucaronyl transferase in neonatal liver- less conjugation and biliary excretion
When do peak levels of neonatal jaundice occur?
3-5 days
How does neonatal phototherapy treat jaundice?
Converts bilirubin to harmless water soluble isomers
