1.) Placenta , Umbilical Cord , Amniotic Sac

Question 1

Placenta ?

Answer 1

Temp organ that serves as an interface between the mum and fetus facilitating essential functions such as nutrient uptake , eliminating waste , gas exchange , hormone production

Question 2

Structure of placenta ?

Answer 2

22cm diameter , 2cm thickness , 0.7kg weight , disc shaped

Question 3

The placenta can be in which other shapes ?

Answer 3

Disc , circular , oval , heart shaped

Question 4

When does placental dev begin ?

Answer 4

2nd week and full functionality around 12th week

Question 5

The placenta originates from ?

Answer 5

The blastocyst , with the fetal component derived from the chorion frondosum and maternal part decidua basalis

Question 6

What is the decidua ?

Answer 6

modified endometrial lining of the uterus during pregnancy

Question 7

Types of decidua ?

Answer 7

1.) Basalis underlines the implantation site , part of placenta.

2.) Capsularis covers the embryo

3.) Parietalis lines the rest of the uterine cavity

Question 8

during implantation the blastocyst sinks into the uterine wall which decidual layer does it sink into ?

Answer 8

Decidua basalis

Question 9

What are the functions of the placenta ?

Answer 9

Nutrients and gas exchange : transfer 02 and nutrients to fetus while removing co2

Immune protection : Transfers maternal IgG antibodies to fetus providing passive immunity.

Hormone production : HCG , Estrogen , progesterone , human placental lactogen (helps fetal growth , reg maternal metabolism )

Question 10

maternal circulation ?

Answer 10

maternal spiral arteries supply blood to the intervillous space where exchange occurs with placental villi , blood returns to the uterus via endometrial veins

Question 11

What is hcg ?

Answer 11

It helps thicken a person’s uterine lining to support a growing embryo and tells the body to stop menstruation

Question 12

How does hcg tell the body to stop the menstrual cycle ?

Answer 12

hCG (human chorionic gonadotropin) maintains the corpus luteum, which continues to produce progesterone.

Progesterone prevents the uterine lining from shedding, thereby stopping the menstrual cycle during pregnancy.

Question 13

What is the corpus luteum ?

Answer 13

Its a temporary mass of cells that form on the ovary each menstrual cycle it appears in one of the ovaries contains follicular granulosa cells and follicular theca cells

Question 14

When does implantation occur ?

Answer 14

Implantation occurs about eight to nine days after fertilization

Question 15

What are the steps to forming a blastocyst ?

Answer 15

Fertilisation , day 1 zygote , then day 3 morula (16-32) cells , then day 4 blastocyst 100 cells

Question 16

Post-delivery, the umbilical vein degenerates into the ?

Answer 16

ligamentum venosum , and the arteries form part of the umbilical ligaments

Question 17

What is the structure of the maternal side of the placenta?

Answer 17

The maternal side is lobulated, containing cotyledons, which are subdivisions made up of chorionic villi anchored to the uterine wall.

Question 18

How does amniotic fluid contribute to fetal lung development?

Answer 18

The fluid allows the fetus to practice breathing movements, which helps develop and expand the lungs.

Question 19

What is the umbilical cord ?

Answer 19

its the lifeline bet the fetus and placenta.

Question 20

when does the umbilical cord form ?

Answer 20

5th week replacing yolk sac as the primary source of nutrients

Question 21

length and diameter of umbilical cord ?

Answer 21

20 inches length and 0.75 inches in diameter

Question 22

how many arteries/veins in umbilical cord?

Answer 22

2 umbilical arteries carry deoxygenated blood from fetus to placenta

1 umbilical vein returns oxygenated blood to fetus surrounded by Whartons jelly which protects the vessels from compression

Question 23

Name 3 umbilical cord pathologies ?

Answer 23

1.) Umbilical cord compression can reduce 02 supply.

2.) Umbilical cord prolapse , the cord descends before the fetus during delivery

3.) Vasa previa , fetal blood vessels cross near the cervical opening.

Question 24

Amniotic sac ?

Answer 24

thin protective membrane that encloses the dev fetus and amniotic fluid

Question 25

Name the 2 layers of the amniotic sac ?

Answer 25

1.) Amnion , inner layer enclosing fluid.

2.) Chorion , outer layer which is part of the placenta.

Question 26

Amniotic fluid function ?

Answer 26

Cushions and protects fetus , allowing free movement , prevents compression

Question 27

amniotic fluid is composed of ?

Answer 27

Initially maternal plasma , it is then replaced by fetal urine y 20 weeks

Question 28

What are the vol changes of amniotic fluid from 10-20 weeks and 28th week and 42 week ?

Answer 28

10-20 weeks increases from 25ml to 400ml and by 28th week it peaks a 800ml , reduces to 400ml by 42 weeks

Question 29

Name 3 pathologies related to amniotic fluid ?

Answer 29

• Meconium stained fluid , indicates fetal distress risk of aspiration syndrome

-Oligohydramnios low fluid <500ml associated with growth restriction.

-Polyhydrmanios , excess fluid >2000ml linked to gestational diabetes or multiple pregnancies