The Amnion

This is a membranous sac which surrounds and protects the Embryo. When formed first, the amnion is in contact with the body of the embryo, but by about the fourth or fifth week the Amniotic fluid (Liquor Amnii) begins to accumulate within it. This fluid increases in quantity and causes the Amnion to expand and ultimately adhere to the inner surface of the Chorion, which is the outer thicker ring of the amnion with its own finger like Villi. A meticulous examination of the Villi is important for the obstetrician to determine any genetic abnormalities in the male or the female fetus and culturing the chromosomes. The amniotic fluid increases in quantity up to the sixth or seventh month of pregnancy, after which it diminishes somewhat. At the end of pregnancy it amounts to about 1 liter. It allows the free movements of the fetus during the later stages of pregnancy, and also protects it by diminishing the risk of injury from outside the abdomen. This contains a small amount of solids like, urea, inorganic salts, protein, and frequently, a trace of sugar.

Umbilical Cord

This is the lifeline between the fetus and the placenta in the uterus. It is formed by the fifth week of development and functions throughout pregnancy to protect the vessels that travel between them.

Formation and structure of umbilical cord

Normally there are two arteries and one vein., embedded within a loose, proteoglycan rich matrix known as Wharton’s jelly. This jelly has physical properties much like a polyurethane air pillow, which is resistant to