Week 3 Flashcards
What are the 4 main roles of the placenta?
Transport
Immunological
Endocrine
Metabolic
What is the transport role of the placenta?
Transport of respiratory gases including
oxygen and carbon dioxide
nutrients & hormones
Removal of waste products & electrolytes
What is the immunological role of the placenta?
The placenta provides an effective barrier against most large bacterial microorganisms but some do cross the placenta
What is the endocrine role of the placenta?
The placenta synthesises many hormones including Oestrogen Progesterone hCG hPL
What is the metabolic role of the placenta?
The placenta synthesises Glycogen Cholesterol Fatty acids Enzymes Which are used by the baby and the placenta
What is the placenta’s appearance?
20cm in diameter 2.5cm thick at the centre Round in appearance Bright red tissue Contains maternal blood Vessels easily seen 2 x arteries 1 x vein 2 x membranes clear & shiny 15-20 cotyledons
What are the 2 membranes of the placenta?
The chorion - thick opaque, uterine side (outer)
The amnion - stronger, clear & smooth, feral side (inner)
What is the cord appearance?
1 x vein & 2 x arteries = 3 blood vessels
50cms long
2cms thick
Can be short impeding birth
Can be long and wrapped around the baby
Can have knots
Wharton’s jelly mostly protects the vessels
What are Monochorionic/Monoamniotic twins?
2 babies
1 placenta
1 membrane
Rare - identical
What are Monochorionic/Diamniotic twins?
2 babies
1 placenta
Separate membranes
Most likely identical
What are Dichorionic/Diamniotic twins?
Fused placenta
2 babies
Separate placentas
Fused within there own membrane
What are Dichorionic/Diamniotic twins?
Separate placenta
2 babies
Completely separate placentas
May imbed in different areas of the uterus
Explain the fetal skull?
The membrane gets populated by ossification centres then calcification spreads outwards
Explain fetal skull in premature baby’s?
The skull doesn’t offer protection to the brain as if a baby was term.
Explain fetal skull in postmature baby’s?
The bones to continue to grow the head is larger and could get obstructive during labour. Slow long process. All those bones have a centre for ossification that grow outward.
