Final answer:
Proteoglycans in tendons primarily function to form hydrated gels that resist compression, contributing to the mechanical integrity and resilience of tendons in the extracellular matrix.
Step-by-step explanation:
The most predominant proteoglycan in tendons has the crucial function of forming hydrated gels, which are capable of resisting compression. This action is vital for the structural integrity and mechanical properties of tendons, which are connective tissues that connect muscles to bones. Proteoglycans are made of a core protein to which glycosaminoglycans (GAGs) are covalently attached. The extracellular matrix, which includes collagen fibers interwoven with proteoglycans, is essential for holding cells together, allowing tissue formation, and facilitating cellular communication.
Fibroblasts, the most abundant cells in connective tissue, secrete polysaccharides and proteins that combine with extracellular fluids to produce a viscous ground substance. This ground substance, primarily comprised of proteoglycans, traps moisture and contributes to the gel-like nature of the extracellular matrix surrounding the collagen fibers within tendons. Therefore, the primary function of these proteoglycans is to ensure tendons have the necessary resilience and pliability to perform their biomechanical tasks.