The human round window membrane. An electron microscopic study

Area of Science:

• Otolaryngology
• Anatomy
• Histology

Background:

• The round window membrane is crucial for hearing.
• Its detailed ultrastructure is not fully understood.
• Understanding its layers is vital for middle ear surgery and treatments.

Purpose of the Study:

• To examine the ultrastructure of the normal adult human round window membrane.
• To describe the layered composition of the round window membrane.
• To differentiate it from "false" round window membranes.

Main Methods:

• Transmission electron microscopy was used.
• The normal adult human round window membrane was analyzed.
• Mucosal membrane veils forming "false" round window membranes were also examined.

Main Results:

• The normal round window membrane consists of three layers: epithelial, fibrous, and mesothelial.
• The fibrous layer contains collagen, elastin, fibrocytes, vessels, and nerves.
• "False" round window membranes also exhibit three layers but differ in their innermost layer.

Conclusions:

• The normal round window membrane has a unique three-layered structure.
• "False" round window membranes, while similar, have distinct ultrastructural differences.
• These findings contribute to the understanding of middle ear anatomy and pathology.