The lipid-rich extracellular matrix of the horn is part of which structure?

• A. Intercellular cement
• B. White line
• C. Sand cracks
• D. Spiral

Answer: (A)

The lipids-filled extracellular matrix in horn serves as intercellular cement, binding the keratinocytes together to form a tough, cohesive, and water-resistant structure. Horn tissue is produced by keratinocytes, and the spaces between these cells are filled with this lipid-rich cement, which helps prevent water loss and provides mechanical strength. Other terms describe different horn features or growth patterns, not the glue between horn cells, so the lipid-rich matrix is best described as intercellular cement.