vitell(i)-

Also vitello‑.

The yolk of an egg.

Latin vitellus, yolk.

In medicine and zoology, the vitellus (plural vitelli) is the yolk of an egg or ovum; the adjective relating to the yolk is vitelline (as in the vitelline membrane, a transparent membrane surrounding and secreted by the fertilized ovum, preventing the entry of further spermatozoa); vitellogenin is a protein present in the blood, from which the substance of egg yolk is derived; vitellin is a protein found in the yolks of eggs; vitellogenesis is the formation of yolk.