Mammals are classified as either monotremes, marsupials, or placentals and these differ in the ways in which their embryos develop. Monotremes such as the platypus have retained the egg laying habit of our avian and reptilian ancestors, marsupials develop for a brief time within the uterus and are then born to complete growth and development in a pouch, and placental embryos develop within the uterus and are nourished by a remarkable structure called the placenta. As a placental mammal perhaps you should pause to appreciate this important structure. Among its many functions the placenta supplies the developing embryo with oxygen and nutrients and removes wastes such as carbon dioxide and urea. It is a physical and chemical link between a mother and her offspring. The intent of this post is not to teach physiology but to kindle an appreciation for this unique structure.
A set of goats was born on the farm yesterday. Before disposing of the twin placentas, having just completed their work of 150 days, I was able to capture some images which reveal the delicate membranes and blood supply so important in supporting and in sustaining life.