108 - Normal Child Flashcards
What is physiological anaemia in a newborn?
As RBCs are high at birth, and high o2 sats, there is a negative feedback the causes less EPO to be produced - so anaemia can occur age 5-6 weeks.
What is the circulating blood volume of a new boen?
85ml/kg - around 300ml
Why is jaundice common in newborns?
They have high haemoglobin levels at birth, and the RBCs have a shorted lifespan, and liver enzymes are immature, so combined can cause jaundice for around 10 days
What is in colostrum?
Initial breast milk - 2/3 days
Low volume
High energy
Rich in proteins and immune calls, immuniglobulins and Growth factors
What are the bowels filled with at birth?
Meconium
What are the 4 key areas adaptation that occurs at birth?
Respiratory
Circulatory
Thermal regulation
Metabloic adaptation
What occurs in the respiratory adaptation at birth?
In labour hormonal changes start absorption of amniotic fluid from alveoli
First breath expels the rest
What circulatory adaptions occur at birth?
The Ductus arteriosus must close - occurs as the lungs fill with air, the pulmonary arteries dilate, the resistance falls, blood goes to the lungs and the ductus closes. Contraction of smooth muscle helps it close.
Foramen Ovale must close - blood is shunted from R atrium to Left in utero so less goes up the pulmonary artery. However at birth oxygenated blood enters the L atrium, the pressure increases, less blood returns from the placenta reducing the pressure in the R atrium, which causes the foramen to close against the septum.
What thermal regulation adaptations occur at birth?
Neonates can’t sweat of shiver, and their cutaneous blood flow is very sensitive to temperature changes.
They have brown fat deposits which allows them to do non-shivering thermogenesis.
Their bodies are covered in vernix, a cheesy film that helps maintain their thermoregulation.
What metabolic changes occur at birth?
constant supply of nutrients cut off.
Can survive for 24hrs via glycogenolysis and gluconeogenesis
What is necessary for growth?
Growth hormone + hormones
Adequate diet
Absence of Stress
Genetics
What are the 4 principles of growth and development in embryology?
Change in size
Differentiation
Organisation/Pattern formation
Morphogenesis
when is the embryonic stage?
0-8 weeks
When is the foetal period of development?
8 weeks - birth
Fertilisation to neurulation occurs between which days?
0 - 18 days
When does the morula form? What surrounds it?
Day 4 - 16 cells + ball
Surrounded by the zona pellucida
What 2 cell layers does the morula split into? What is it now called?
Inner cell mass - embryoblast
Outer cell mass - trophoblast
= the blastocyst
When and where does it squeeze out of the zona pellucida?
Day 5, in the uterus
When does implantation occur?
Day 6.
What does the trophoblast form? What does it merge with?
Merges with the endometrium, forms the syncytiothrophoblast
When does the amniotic cavity form? What lines it and secretes the fluid?
Day 8
Amnioblasts
When does hCG start being produced? From where?
Day 9
From the syncytiotrophoblast
What are lacunae and what do they become?
Cavities in the syncytiotrophoblast that errode and join maternal blood, form the maternal/foetal blood interface
What forms to become the chorionic cavity?
The extra-embryonic colom
What does ectoderm become?
Epidermis, nervous system, retina
What does the mesoderm become?
muscles, blood, skeleton, cardio, connective tissue…
What does the endoderm become/
Epitelia of the resp and GI tracts
How long is pregnancy from a clinicians point of view? When does it start?
40 weeks - from LMP
How long is pregnancy from an embryologists point of view?
38 weeks - from fertilisation
