Which component of the extracellular matrix primarily assists in resilience and elasticity?

The component of the extracellular matrix that primarily contributes to resilience and elasticity is elastin. This protein fiber is crucial for allowing tissues to stretch and then return to their original shape. Elastin is found in various connective tissues, such as skin, lungs, and arteries, where its elastic properties enable these tissues to accommodate changes in shape or volume without tearing.

While other components of the extracellular matrix, such as collagen, play important structural roles and provide tensile strength, they do not allow for the same degree of stretch and recoil as elastin. Fibronectin serves as a glycoprotein that helps cells adhere to the extracellular matrix, and proteoglycans function as molecular "sponges" that retain water and provide hydration, but neither has the specialized role that elastin has in imparting elasticity and resilience to tissues. Thus, elastin is the primary component responsible for these specific properties in the extracellular matrix.