zona pellucida

Full Definition

A specialized extracellular matrix that surrounds the oocyte and early embryo, playing crucial roles in fertilization and early development. The zona pellucida protects the developing embryo and must be penetrated by sperm during natural fertilization. In assisted reproductive technology, the zona pellucida may be artificially opened through assisted hatching procedures to improve implantation rates in certain patient populations.

Usage

Usage note: Latin term often shortened to 'zona' in clinical contexts.

In Context

• "Assisted hatching involves creating an opening in the zona pellucida." — Procedure description
• "The zona pellucida appeared thick on microscopic examination." — Laboratory report