The document introduces placenta, its types, and functions in different animals. It defines placenta as the intimate connection between the fetal and maternal tissues that allows physiological exchange. Placentas are classified based on whether they cause decidua loss during birth and their gross shape. Functions of the placenta include transporting nutrients and gases, storing waste, biosynthesizing hormones, excreting wastes, acting as a protective barrier, and providing passive immunity transfer from dam to fetus.

1. INTRODUCTION TO PLACENTA , ITS
TYPES AND FUNCTIONS IN
DIFFERENT ANIMALS:
Presented By:
Saleem khan
BVSc&AH student
(internship)
from CVASc ,Pantnagar
Email:skhan6548@gmail.com

2. PLACENTA
It is defined as intimate apposition or fusion of foetal
membrane to the maternal endometrium to permit
physiological exchange between foetus and mother.
It is composed of 2 parts :
1) foetal part- Allantochorion.
2)Maternal part- endometrium.
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3. TYPES OF PLACENTA
The placenta classified on the basis of :
1)Loss of maternal tissue ( decidua ) during birth :
a) Deciduate :
- conciderable loss of tissue shed off along with placenta.
-also k/a conjoined placenta or placenta Vera .
-seen in :Bitch and cat (moderate),human and monkey(extreme).
b)Non- deciduate :
-no loss of matrnal tissue
-also k/a apposed type or adeciduate placenta
-seen in : most of the farm animals like ,cow , buffalo , sheep ,goat
,mare and sow.

4. 2)Grossshape or anatomy :
-i.e distribution of villi .

6. c)Histological characteristics of maternal foetal barrier:
-This depends upon no. of tissue layers presens that separate
two vascular systems(mother& foetus)

7. FUNCTIONS OF PLACENTA
-Nutrition of foetus is haematotrophic type and therefore
vascularization of placenta is important.
-Placentaperforms following functions:
1)Transportation : Transportation of nutrients, gasses of respiration,
water,electrolyte,inorganic nutrients(Na,Fe,Cu,Ca,P etc.),water soluble
vitamins and hormones.
2) Storage: Storage of waste products ,foetal urine , saliva,meconium.
3)Biosynthesis: Biosynthesis of hormones (oestrogen, progesteron,
gonadotropins).
4)Excretion: Excretion of fluid waste products like urea of foetal
metabolismthat escape into placenta having kidney like function.
5)Protective Barrier: Placenta is impermeable to bacteria and even
larger molecules but this is selective barrier .
6)Immunity: Passive transfer of immunity from dam to foetus in vitro.