Placental and Fetal Flashcards
What happens during the first trimester to spiral arteries?
They become blocked. No maternal blood flowing so foetus rely on nutritional material in spaces between fetal tissue and maternal tissue.
What sort of placenta is found in humans?
Discoid placenta (placenta arranged in a circular shape).
Why do humans have a discoid placenta?
Increases in oxidative stress, increase in apoptosis and a decrease in proliferation result in placenta regressing.
When do the spinal arteries unplug?
During the second trimester.
Give 2 functions of the placenta.
Respiratory organ. Nutrient transfer. Excretion of fetal waste. Hormone synthesis.
What is the difference between the cytotrophoblast and the syncytiotrophoblast.
Cytotrophoblasts contain mononucleated cells. Syncytiotrophoblasts contain multinucleated cells.
What is the decida basalis?
Area of endometrium between the implanted chorionic vesicle and the myometrium, which becomes the maternal part of the placenta.
Empty spaces of the primary villi are known as…
Lacunae.
The syncytiotrophoblast penetrate what to develop the placenta.
Decida basalis
Define macrosomia.
Overweight at birth. Causes problems during labour, and increases the risk of a still birth.
How many arteries and veins are found within the umbilical cord?
2 arteries. 1 vein.
Are fetal arteries deoxygenated or oxygenated?
De-oxygenated.
Are fetal veins deoxygenated or oxygenated?
Oxygenated.
What are the three structures of the umbilical cord?
Body stalk. Vitelline duct. Allantois.
The endoderm develops the gut tube, which divides into 3 layers. What are these 3 layers?
Foregut. Mindgut. Hindgut.
When do uterine spiral arteries do?
They play a vital role in supplying nutrients to the placenta and fetus from the second trimester.
