Which structure diffuses nutrients through cartilage?

The matrix is the correct answer because it serves as the medium through which nutrients diffuse within cartilage. Cartilage is avascular, meaning it does not contain blood vessels. Instead, the extracellular matrix of cartilage is made up of collagen fibers, proteoglycans, and water, which together facilitate the diffusion of nutrients, oxygen, and waste products. Nutrients move through this gel-like matrix due to concentration gradients, allowing the chondrocytes (the cells found in cartilage) to obtain the necessary substances for their survival and function.

In contrast, capillaries and arteries are part of the vascular system and are responsible for directly transporting blood and nutrients throughout the body. However, because cartilage lacks these blood vessels, they do not play a role in nutrient diffusion in this specific tissue. Lymph vessels are involved in transporting immune cells and excess interstitial fluid but are not primarily responsible for nutrient diffusion in cartilage. Thus, the matrix is essential for nutrient exchange in cartilage due to its unique structural characteristics.