What is the umbilical cord and what is its main function?

The umbilical cord is a long, twisted structure that physically and vascularly connects the fetus to the placenta. Its primary function is to act as a conduit for nutrient and gas exchange between the fetus and mother, supporting fetal development.

What are the key structures found inside the umbilical cord?

The umbilical cord contains two umbilical arteries carrying deoxygenated blood from fetus to placenta, one umbilical vein (left) returning oxygenated blood to the fetus, and Wharton’s jelly, a gelatinous connective tissue that protects the vessels. It also includes remnants of embryonic structures like the vitellointestinal duct and allantois.

How does the umbilical cord develop during embryogenesis?

The umbilical cord develops from the connecting stalk, which is composed of extraembryonic mesoderm. During embryonic folding, it shifts to the ventral umbilical region, connecting the fetus to the placenta, and is enveloped by the amniotic cavity.

What is Wharton's jelly and why is it important?

Wharton's jelly is a gelatinous, protective substance formed from the primary mesoderm of the connecting stalk. It cushions and protects the umbilical vessels from compression, ensuring uninterrupted blood flow between the fetus and placenta.

What are some common clinical complications associated with the umbilical cord?

Common complications include cord prolapse, where the cord descends before the fetus during labor, risking compression and fetal hypoxia; nuchal cord, where the cord encircles the fetal neck, potentially causing strangulation in about 20% of births; and short cord, which can hinder delivery and lead to placental detachment issues.

What are the typical measurements of the umbilical cord at full term?

At full term, the umbilical cord typically measures 50–55 cm in length and 1–2 cm in breadth. These dimensions support its function as a flexible connection between the fetus and placenta.

Umbilical Cord – Structure & Vessels