Download Placenta

The Placenta
The Placenta
• Allows female mammals to carry the young
inside their bodies during early development.
• During pregnancy, the developing foetus
receives all its nutrients via the placenta.
• All the waste products in the foetus’s blood
are removed via the placenta.
• The placenta also produces hormones.
The Placenta
The Placenta
The Placenta
The placenta consists of thousands of
tiny branched fingers of tissue called
CHORIONIC VILLI these project into
the endometrium. The maternal blood
vessels surrounding the chorionic villi
break down forming maternal blood
sinuses
The Placenta
Diagram showing chorionic villi
The Placenta
Table showing exchange of materials across the
placenta
Mother to Foetus
•Oxygen
•Glucose
•Amino acids
•Lipids, fatty acids &
glycerol
•Vitamins
•Ions; Na, Cl, Ca, Fe
•Alcohol, nicotine + other
drugs
•Viruses
•Antibodies
Foetus to Mother
•Carbon dioxide
•Urea
•Other waste products
The Placenta
short diffusion distances;
breakdown of membranes;
placenta has a large S/A:Vol;
because of chorionic villi and lacunae;
slow movement of blood at exchange surfaces;
transport proteins present for facilitated diffusion of glucose;
transport proteins present for active transport of ions and a.a’s;