Fetal membranes, umbilical

cord

and

placenta

Dr. Sanjaya AdikariDepartment of Anatomy

Objectives

• Describe the structure and function of the placenta, umbilical cord and membranes

Chorionic plate

Decidual plate

Chorionic villi

Lacunar/intervillous spaces

Cotyledon (15-20)

Macroscopic appearance of placenta

Placenta – fetal surface

Placenta – maternal surface

Placenta and membranes

What is placental barrier?

2 1

Placental barrier

Functions of the placenta

• Exchange of gases

• Removal of metabolic products

• Nutrition

• Transmission of maternal Ab

• Production of hormones

Placental hormones

• Human chorionic gonadotropin-hCG

• Progesterone

• Oestrogens

• Human chorionic somatomammotropin-

hCS

• RelaxinThese are secreted into the maternal circulation.

Most maternal hormones do not cross the placenta.

2010 30 40 Weeks

hCG

6 12

Maintains the corpus luteum during the initial period of pregnancy

Progesterone

Oestriol

Maintains the pregnancy

Relaxin

Inhibits myometrial contractions

hCS

Lactogenic functionGrowth stimulation

2010 30 40 Weeks

hCG

6 12

Progesterone

OestriolRelaxin

hCS

Unwanted functions of placenta

• Transfer of infectious agents

• Transfer of drugs

Functions of the fetal membranes

• Protection/shock absorption

Umbilical cord

umbilical arteries umbilical vein

Wharton’s jelly

References

• Review of medical physiology by William F.

Ganong

• Medical embryology by Jan Langman

• http://www.answers.com/topic/umbilical-cord