Neonatal Physiology Flashcards
During what week does the foetal heart start beating?
4th week
When is the critical period of heart development?
day 20-50 after fertilisation
What is the purpose of the ductus venosus?
connect umbilical vein to IVC
Foetal circulation.
mum—oxygenated blood via umbilical vein—ductus venosus— IVC—right atrium—foramen ovale—-left atrium—left ventricle–aorta—body—umbilical artery–placenta and mum
What is the ductus arteriosus and what is its function?
- connects the foetal pulmonary trunk to the aorta
- protects lungs against circulatory overload-carries mostly low oxygenated blood
What is a: 1. normal heart rate 2. tachycardia 3. bradycardia in a full term newborn (37 weeks)?
- 120-160bpm is normal
- > 160bpm is fast
- <100bpm is slow
Over what period of time must you listen to get an accurate baby respiratory rate and why? What is a normal range per minute for newborn respiratory rate?
- must listen for a minute due to physiological periodic breathing
- normal range is about 30-60 breaths/minute
What blood pressure is relatively normal for a newborn?
70-77/40-49mmHg
How do babies regulate their body temperature?
lipolysis from brown fat
What are non-invasive means of monitoring efficiency of a newborn’s breathing?
- blood gases
- transcutaneous pCO2/O2 measurement
What weight loss is normal in a newborn and why?
- up to 10% weight loss can be normal
- loss due to shift of interstitial fluid to intravascular or diuresis
What issue is there with fluid balance in a premature baby?
- less fat in body composition
- increased loss through kidney
- increased insensible loss
Why can anaemia be physiological in the newborn?
takes time to start increasing production of erythropoietin and to change foetal haemoglobin production to adult haemoglobin production
