Human Placenta's Anatomical Morphology

Description

Placental cotyledons dominate the maternal surface, forming a lobulated mosaic of polygonal units separated by shallow interlobular septa. Near the center, the chorionic plate forms the fetal boundary deep to these lobules, with the placental parenchyma (villous tissue) occupying the thickness between chorionic and basal plates. From this broad surface perspective, the cotyledons sit superficially and peripherally, while the chorionic plate is positioned deeper and more centrally as a smooth, gently convex plane. Placental shape and thickness are easy to judge. Cotyledonary morphology matters when you correlate gross findings with uteroplacental perfusion and placental separation after delivery. Irregularly small, fragmented, or infarcted cotyledons raise concern for maternal vascular malperfusion, hypertensive disease of pregnancy, or focal placental abruption, and a missing cotyledon on inspection can indicate retained placental tissue with postpartum hemorrhage risk. The fixed surface view makes the boundaries of each cotyledon legible, so you can teach how septa partition the intervillous space and why the maternal side looks granular compared with the smoother chorionic surface encountered on the fetal side. Use this illustration in obstetrics teaching on placental gross examination, in pathology atlases describing infarction and intervillous thrombus distribution by cotyledon, or in clinical handouts that explain what clinicians look for when confirming placental completeness in the delivery suite. It also fits placentation modules in embryology, linking chorionic plate anatomy to fetal membranes and the maternal basal plate at implantation. Anatomical accuracy verified by SciePro's Medical Advisory Board.