Foetal and Neonatal Physiology Flashcards
What is the greasy substance which protects the skin of an unborn baby?
Vermix
What is the name given to the five stages of Lung development? How long does each stage take?
Embryonic (5 weeks) Pseudo-glandular (10 weeks) Canalicular (10 weeks) Saccular / terminal sac (10 weeks) Alveolar (5 weeks)
In a baby’s lungs, from what of the five developmental stages is gas exchange possible?
Terminal sac stage (>25 weeks)
Give examples of congenital conditions which affect lung development in a baby?
- Pulmonary hypoplasia (can be caused by Diaphragmatic hernia)
At what stage is surfactant produced in a pregnancy?
Last 8 weeks of pregnancy (in the third trimester)
What is the role of pulmonary surfactant?
Phospholipid, whereby the hydrophobic / hydrophillic interfaces adsorb the air-water interface of alveoli, reducing surface tension
Babies born before surfactant production suffer with…?
Respiratory distress syndrome (RDS)
Give 6 examples of causes for where a baby might have a pulmonary surfactant deficiency
- Congenital absence
- Prematurity
- Infection
- Acidosis
- Hypothermia
- Meconium aspiration
What drugs can be prescribed to the mother of an unborn baby which may be pre-term to reduce the risk of RDS?
Antenatal / Maternal steroids
What cells produce pulmonary surfactant?
Type II Pneumocytes
On an X-ray, how might a newborn baby with RDS look like?
Ground glass appearance
What is the definition of pneumothorax?
Collapsed lung, caused by air entry between the lung and chest wall -> Collapse
What two components is the placenta derived from?
Uterine wall & Trophoblastic tissue
What is arterial supply and venous supply of the umbilical cord?
2 Umbilical arteries (de-oxygenated blood)
1 Umbilical vein (oxygenated blood)
What are the two foetal cardiac shunts?
- Ductus arteriosus (Pulmonary artery -> Aorta)
2. Foramen ovale (RA -> LA)
What is the Ductus Venosus?
A structure which shunts left umbilical vein blood flow directly into the IVC, bypassing the liver
What lipid compound maintains patent Ductus Arteriosus?
Prostaglandins
Aside from surgery, what can be administered to close a patent Ductus Arteriosis?
Prostaglandin Inhibitors
What is Hypoplastic Left Heart Syndrome?
Congenital heart defect, where left side of heart is severely underdeveloped
What is PPHN?
Persistent Pulmonary Hypertension of a Newborn
Describe the pathophysiology of PPNH (Persistent Pulmonary Hypertension of the Newborn)
- Stiff lungs -> pulmonary arterioles stay constricted
- Pulmonary pressures are high (pulmonary hypertension)
- Blood difficult to pump through lungs
- Easier to go through ductus arteriosus and R->L shunt at foramen ovale
- Persistent foetal circulation
When does Foetal Hb switch to Adult Hb?
Drops at ten weeks
