Placental anatomy and physiology Flashcards Preview

Abnormal placentation > Placental anatomy and physiology > Flashcards

Flashcards in Placental anatomy and physiology Deck (7)
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1

What makes up the fetal and maternal portions of placenta?

Fetal:
Villi of the chorion frondosum

Maternal:
Decidua basalis

2

When does placental development begin?

At blastocyst implantation around day 7-8 of embryogenesis, where syncitiotrophoblast begin to invade into decidua basalis

3

What are the features of decidualisation and what factors drive the process?

Causes:
- Rising progesterone
- Blastocyst invasion

Features:
- Increased vascularisation and swelling of maternal vessels
- Increased oedema
- Increased glycogen and lipid stores in endometrial cells
- Synciototrophoblast driven erosion of endometrium at implantation site

4

When do cotyledons form and how?

Around 4 months - decidua septa divide placenta in 15-20 discrete cotyledons

5

What layers does gas exchange occur between fetal side of the placenta and the junctional zone?

Syncitiotrophoblast and endothelial cells of fetal circulation

6

What are the roles of the placenta?

- Gas exchange
- Nutrient / glucose supply
- Removal waste products
- endocrine function
- Immunological function - line of defence against fetal infection and presence of immunoglobulins

7

What hormones are made by the placenta?

9 hormones!!
- HCG (secreted by syncitiotrophoblast; has 2 subunits - a and B - alpha unit is identical to LH/FSH/TSH; peaks at 9-12 wks)

- hPL (is anti-insulin - i.e increases insulin resistance)

- oestrogen

- progesterone

- corticosteroid

- CRH

- Relaxin (causes relaxation of ligaments and cervical stroma in preparation for childbirth)

- ACTH

- TSH