What is a placental cotyledon:
Functional unit of the placenta is called a fetal cotyledon or placentome,which is derived from a major primary stem villus. These stem villi pass down through the intervillous space to anchor onto the basal plate.About 60 stem villi persist in human placenta. Thus each cotyledon(totalling 15-29) contains 3-4 major stem villi. Reference : Dutta Textbook of Obstetrics &th edition page no 31
All branches from one stem villi
Area supplied by one spiral aery
Quaer of placenta
Area drained by one terminal villi
General obstetrics