What are the three types of cartilage and a key histologic difference between them?

• A. Hyaline Cartilage (Type II Collagen, Glassy Matrix); Elastic Cartilage (Elastic Fibers in Matrix); Fibrocartilage (Dense Collagen Bundles)
• B. Hyaline Cartilage, Elastic Cartilage, Fibrocartilage; All Have Identical Matrices
• C. Hyaline Cartilage Only
• D. Elastic Cartilage Only

Answer: (A)

Cartilage comes in three forms, each with a distinct extracellular matrix that defines its appearance and function. Hyaline cartilage has a smooth, glassy matrix rich in type II collagen and is usually surrounded by a perichondrium. Elastic cartilage is similar in overall appearance but contains a network of elastic fibers in the matrix, providing flexibility, and it also has perichondrium. Fibrocartilage, by contrast, has densely packed collagen fibers (mostly type I) in a sparse ground substance and typically lacks a perichondrium, making it very resistant to compression and shear.

The key histologic difference among the three is the matrix fiber content: hyaline with type II collagen, elastic cartilage with elastic fibers, and fibrocartilage with dense collagen bundles.