01 / Location & anatomical relationships
Attached to the inside of the uterus during pregnancy.
02 / Structure & organization
Fetal chorionic villi interact with maternal blood in an exchange space, while fetal blood remains within its vessels. The organ also produces hormones that support pregnancy. The umbilical cord links fetal circulation with placental vessels.
03 / Function
It allows oxygen and nutrients to pass from the pregnant person's blood to the developing baby without their blood normally mixing.
04 / Mechanism
Tiny branching structures bring the developing baby's blood close to the pregnant person's blood supply. Oxygen, nutrients and wastes cross between them through thin tissues. The umbilical cord links the baby with this temporary organ.
Working together: reproductive system
Bodies develop in different ways. During puberty, hormones help reproductive organs mature. A pregnancy can begin when a sperm cell fertilizes an egg cell, and development continues in the uterus.
Meet this body system →FOR DEEPER STUDY
Connect structure with function
Maternal and fetal circulations are closely apposed but normally remain separate. The placenta is a temporary pregnancy structure and is not shown as a routine organ in the nonpregnant 3D model.
Check your understanding
Locate the placenta in relation to its neighbors. Explain how the structural features described above support its function, then distinguish it from a nearby structure with a different role.
Keep learning
Continue with OpenStax Anatomy and Physiology for system-level study. This atlas is educational and has not undergone independent medical peer review.