Wharton's jelly

Wharton's jelly is a gelatinous substance within the umbilical cord, composed of cells that originate in the original egg and sperm of conception. It is largely made up of mucopolysaccharides (hyaluronic acid and chondroitin sulfate). As a mucous tissue it protects and insulates umbilical blood vessels.

Wharton's jelly, when exposed to temperature changes, collapses structures within the umbilical cord and thus will provide a physiological clamping of the cord, an average of 5 minutes after birth. In some cases, such as in water birth with the cord immersed, the Wharton's jelly reaction will occur much later.

Etymology
It is named for the English physician and anatomist Thomas Wharton (1614-1673) who first described it in his publication Adenographia, or "The Description of the Glands of the Entire Body", first published in 1656.