PLACENTA IS A ADDITIONAL STRUCTURE THAT DEVELOPS DURING PREGNANCY TO PROVIDE NOURISHMENT TO FETUS.

1. P R E P A R E D B Y :
SRUJANI SWETASINA DASH
NURSING TUTOR
G.N.M.INSTITUTE,
A.N.M.M.C.H, GAYA
Placenta

2. Objectives
 Definition
 Characteristics
 Development
 Structure
 Diagram
 Function
 Conclusion
 Bibliography

3. Definition
 Structure developed in a pregnant uterus through which
the fetus derives nutrition.
 Placenta establishes connection between mother
and fetus through the umbilical cord.

4. Characteristics
 Discoid
 Hemochorial
 Deciduate

5. Development
 Begins at 6th week of gestation.
 Completed by 12th week.
 Two sources-
Chorion Frondosum (fetal component)
Decidua Basalis (maternal component)

6. Structure at term
 Shape : Circular Disc
 Diameter : 15-20 cm
 Thickness : 2.5cm at its centre
Thins off towards edge
 Weight : About 500gms at term
 Proportion :1:6 (weight of placenta: weight of baby) at term
 Attachment : Upper part of body of uterus near cornua.
 Invasion : Grows/invades upto decidua compact and Nitabuch’s
membrane prevent further invasion into deeper layer.
 Separation : Occurs after birth through the line of decidua
spongiosum.
 Surfaces :2 surfaces and a peripheral margin
Fetal and Maternal

7. contd
Presents 2 surfaces (fetal and maternal) and a peripheral margin
Fetal surface-
 Covered by smooth and glistening amnion
 Umbilical cord attached to it at centre
 Umbilical vessels visible beneath amnion
 4/5th is fetal origin
Maternal surface-
 Rough and spongy
 Dull red colour
 15-20 polygonal cotyledons limited by fissures
 1/5 is maternal origin

8. Fetal surface Maternal surface
Diagram of placenta

9. A human placenta

10. Functions
 Transfer of nutrients and oxygen:
Fetus derives nutrients and oxygen from placenta.
 Excretion:
Waste products from fetus is excreted to maternal blood in
placenta.
 Secretion:
Produces hormones such as HCG, progesterone etc and
enzymes such as oxitocinase necessary to maintain pregnancy.
 Barrier:
Act as protective barrier to fetus against noxious agent.
 Immunological:
Provides immunological protection to fetus.

11. Conclusion
Placenta is a vital structure and the knowledge on its
structure helps in detecting the abnormalities thereby
saving the life of mother and the baby.

12. Assignment
 Observe the structure of placenta in the labour room
and write down the observations.
 Draw the structure of placenta , attachment of
placenta.

13. Bibliography
 Dutta D.C, “Textbook Of Obstetrics”, New Central
Book Agency(P)LTD, 6th edition, Pg.28-29
 Jacob Annamma, “A Comprehensive Textbook of
Midwifery”, Jaypee Brothers Medical
Publishers(P)LTD, 2nd edition, Pg.75-78
 Myles, “ Textbook for Midwives”, Churchill
Livingstone Publishers, 13th edition, Pg.143-147

14. EVALUATION
Class Test – 15 marks for 5 minutes after end of session
I. Fill in the blanks: 10×1= 10
 Diameter of Placenta is______________.
 The fetal component of placenta is called as
_________________.
 Placenta is developed from ______________ part of
blastocyst.
 Development of placenta begins from ___________ weeks.
 Cord is attached to ______________ surface of placenta.
 Ratio of weight of placenta with fetus is ____________.
 Maternal component of placenta is called as _____________.
 The characteristic of placenta is ___________,
______________ and ___________.
II. List out the functions of placenta. 5

15. ANSWER KEY
I. Fill in the blanks:
 Diameter of Placenta is 15-20 cm.
 The fetal component of placenta is called as chorion frondosum.
 Placenta is developed from trophoblast part of blastocyst.
 Development of placenta begins from 6 weeks.
 Cord is attached to fetal surface of placenta.
 Ratio of weight of placenta with fetus is 1:6.
 Maternal component of placenta is called as decidua basalis.
 The characteristic of placenta is discoid, hemochorial and deciduate.
II. List out the functions of placenta.
 Transfer of nutrients and oxygen.
 Secretion
 Excretion
 Barrier
 Immunological

16. Thank You