The document provides information about the placenta, including its definition, characteristics, development, structure, functions, and conclusions. It defines the placenta as the structure developed in the pregnant uterus through which the fetus derives nutrition and establishes a connection between the mother and fetus via the umbilical cord. Key points covered include that the placenta is discoid, hemochorial and deciduate in nature. It develops from 6-12 weeks of gestation from the chorion frondosum and decidua basalis. At term, it is circular, 15-20cm in diameter, and weighs about 500g. Its functions include the transfer of nutrients and oxygen to the fetus, excretion of fetal waste

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