BGDA Practical Placenta - Cord Development

Placental/Umbilical Cord

The placental cord (umbilical cord) is the connecting region between the functional placenta and the embryo/fetal umbilical region. The human cord varies physically in overall length, increasing to about 60 to 70 cm at term, degree of coiling, number of vessels and insertion site on the placenta. This extraembryonic structure contains the placental blood vessels and allantois.

Placental Arteries and Vein

Placental Cord Histology

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  Placental cord cross-section

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  Placental vein

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  Placental artery

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  Placental allantois

Placental Cord Ultrasound

Ultrasound image of transverse scan through the cord show the method of estimation of the cross-sectional area.

Wharton's Jelly

Placental cord cross-section

• placental cord connective tissue (substantia gelatinea funiculi umbilicalis)
• amorphous substance containing glycosaminoglycans, proteoglycans and hyaluronic acid.
• cells similar to smooth muscle that allows a contractile function.
• network of collagen that form canaliculi and perivascular spaces.
• maintain blood flow to the fetus during placental cord compression during pregnancy or delivery.

First described and named after Thomas Wharton (1614–1673) an English physician and anatomist.

Hofbauer Cells

• located the core of placental villi
• macrophages with micropinocytotic activity and phagocytosis ability
• possible paracrine role for early stages of placental vasculogenesis
• express angiogenic growth factors (VEGF)

Fetal Circulation