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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