placenta

1. accessory placenta

2. surfaces

2.1. maternal

2.1.1. rough devided into 15 to 20 cotyledons

2.1.1.1. smooth covered by amnion and the umbilical cord attached near the centre of this surface the umbilical vessels is seen

2.2. fetal

3. abnormalities

3.1. in size and shape

3.1.1. bidiscoid placenta

3.1.2. placenta accreta

3.2. in position

3.2.1. placenta previa lateralis

3.2.2. placenta previa marginalis

3.2.3. placenta previa centralis

3.3. abnormal attachment of umbilical cord to the placenta

4. fate

4.1. sheds out during delivery

5. origin

5.1. maternal surface

5.1.1. decidua basalis

5.2. fetal surface

5.2.1. chorionic plate

6. protective

7. excretory

8. structures

8.1. chorionic villi

8.2. intervillous spaces

8.3. cytotrophoplastic shell

8.4. placenta septa

8.5. cotyledons

8.6. placenta barrier

9. functions

9.1. repiratory

9.2. nutritive