Placenta

Question 1

How much blood is contained within the intervillous space of a mature placenta?

Answer 1

150 mL which is replenished 3-4 x each minute.

Question 2

What makes up the fetal portion of the placenta?

Answer 2

Villous chorionic

Question 3

What makes up the maternal portion of the placenta?

Answer 3

Decidua basalis

Question 4

How many umbilical arteries does a normal umbilical cord contains, and what type of blood does it carry to the placenta?

Answer 4

There are TWO umbilical arteries and they carry DEOXYGENATED blood from the fetus to the placenta.

Question 5

Across what type of chorionic villi does exchange between maternal and fetal blood occur?

Answer 5

Across BRANCH villi

Question 6

Describe the order of blood flow of fetoplacental circulation

Answer 6

Poorly deoxygenated blood leaves the fetus –> umbilical arteries –> chorionic arteries –> arteriocapillary venous system within chorionic villi –> gas exchange occurs, oxygenated floor flows –> chorionic veins –> umbilical vein –> fetus

Question 7

Describe the order of blood flow of the maternal-placental circulation

Answer 7

Oxygen rich blood leaves mother through spiral arteries in decidua basalis –> intervillous space –> exchange occurs around branch villi –> flows out through endometrial veins –> returns to maternal circulation

Question 8

List the functions of the placenta (5):

Answer 8

TEEMPT:
Transport of gases, nutrients, drugs and infectious agents
Excretion of waste products
Endocrine synthesis and secretion e.g. hCG
Metabolism e.g. synthesis of glycogen
Protection by maternal antibodies