What is the Placenta?

The term placenta comes from Latin and literally means "squashed cake". It is a temporal organ that acts like a bond between the embryo and the mother and is composed of an intricate network of blood vessels and superficial tissue. Due to its constitution, it allows oxygen, nutrients and anti-bodies to pass through it at the same time that it eliminates the urea and carbon dioxide of the fetuses. The placenta forms around 18th or 20th day of pregnancy and grows until it surrounds the fetus and becomes its size.

The two lateral extremes of the placenta contain an important mass of blood. These marginal hematomas originate from the blood circulation of the mother and they are believed to provide nutrients -- and even iron -- to the puppies.