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Flashcards in Placental function Deck (7)
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1
Q

What are the functions of the placenta?

A
. Lungs (delivery of gases)
. Gut (delivery of nutrients)
. Kidney (excretion of waste products)
. Liver (storage/reservoir of energy)
. Endocrine (placental derived hormones)
. Protective (toxic substances)
2
Q

From least efficient to most efficient name the types of placenta?

A

Epitheliochorial –> endotheliochorial –> Haemochorial

3
Q

What can cause Intra-uterine growth retardation?

A

Inappropriate growth can see glucose levels have dropped due to less glucose transport mechanism in pregnancy. IUGR due to inefficiency of transport mechanisms of Aas and glucose.

GLUT-1 transporters on maternal side are rate limiting step need enough of them. GLUT-3 become more important later in gestation.

Therefore expression of transporters can influence and regulate the transport of key substances like glucose.

4
Q

What is a freemartin and what causes it?

A

.Female offspring of dizygotic twins in a mixed-sex
pregnancy, usually in cattle. Placental fusion
between the male and the female permits
the exchange of fetal cells and fetal hormones.
Male hormones androgenise the female fetus
producing a sterile XX/XY chimeric ‘female”
(Chimerism)

5
Q

What are some of the causes of intra-uterine growth retardation due to environmental factors?

A

Environmental factors
— maternal nutrition and/or nutrient imbalance
— maternal intestinal malabsorption
— ingestion of toxic substances
— environmental temperature and stress
— disturbances in maternal or fetal metabolic and
homeostatic mechanisms
— insufficiency or dysfunction of the uterus
endometrium, or placenta
— poor management

6
Q

What are some of the causes of intra-uterine growth retardation due to placental factors?

A

Placental efficiency impaired by:
— Placental size/weight
— uteroplacental blood flow (Angiogenesis)
— Surface area: placenta wfth maternal endometrium
Placental growth altered with nutrition
— Under- and overnutrition
Multiple fetuses impact on the placenta
— Ruminants: reduced placental blood flow
— Pig runts: small placenta and reduced blood flow

7
Q

How is pre-eclampsia caused?

A

The cytotrophoblast cells don’t invade enough and arteries aren’t made into distended tubes consequently to get blood to the fetus the mother has to work much harder and her heart rate will go up. BP rockets.