Placenta Structure and Function

Structure and Function

• The placenta is a temporary organ that develops in the uterus during pregnancy
• It is responsible for:
  • Oxygen and nutrient supply to the fetus
  • Waste removal from the fetus
  • Production of hormones that support pregnancy
  • Exchange of gases, nutrients, and waste between the mother and fetus

Development

• The placenta develops from the outer layer of cells of the blastocyst (fertilized egg)
• It begins to form around 5-6 days after fertilization
• The placenta is fully formed by 12-14 weeks of gestation

Types of Placenta

• Monochorionic placenta: develops when two or more fetuses share the same placenta (e.g., in twins)
• Dichorionic placenta: develops when each fetus has its own separate placenta (e.g., in twins)

Placental Circulation

• Maternal circulation: the mother's blood supply to the placenta
• Fetal circulation: the fetus's blood supply to the placenta
• The two circulations are separated by the placental membrane, allowing for exchange of substances

Placental Hormones

• Human chorionic gonadotropin (hCG): stimulates the corpus luteum to produce progesterone, supporting pregnancy
• Estrogen: promotes fetal growth and development
• Progesterone: maintains pregnancy and prepares the breasts for lactation

Placental Abnormalities

• Placenta previa: the placenta partially or completely covers the cervix, potentially causing bleeding and complications
• Placental abruption: the placenta separates from the uterus, potentially causing bleeding and fetal distress
• Placental insufficiency: the placenta is unable to supply the fetus with sufficient oxygen and nutrients, potentially leading to growth restriction and other complications

Structure and Function

• The placenta is a temporary organ that develops in the uterus during pregnancy
• Responsible for oxygen and nutrient supply to the fetus
• Responsible for waste removal from the fetus
• Produces hormones that support pregnancy
• Enables exchange of gases, nutrients, and waste between the mother and fetus

Development

• Develops from the outer layer of cells of the blastocyst (fertilized egg)
• Begins to form around 5-6 days after fertilization
• Fully formed by 12-14 weeks of gestation

Types of Placenta

• Monochorionic placenta: shared by two or more fetuses (e.g., in twins)
• Dichorionic placenta: separate for each fetus (e.g., in twins)

Placental Circulation

• Maternal circulation: mother's blood supply to the placenta
• Fetal circulation: fetus's blood supply to the placenta
• Separated by the placental membrane, allowing for exchange of substances

Placental Hormones

• Human chorionic gonadotropin (hCG): stimulates corpus luteum to produce progesterone, supporting pregnancy
• Estrogen: promotes fetal growth and development
• Progesterone: maintains pregnancy and prepares breasts for lactation

Placental Abnormalities

• Placenta previa: placenta partially or completely covers the cervix, potentially causing bleeding and complications
• Placental abruption: placenta separates from the uterus, potentially causing bleeding and fetal distress
• Placental insufficiency: unable to supply fetus with sufficient oxygen and nutrients, potentially leading to growth restriction and complications