Which molecules are primarily found in the extracellular matrix (ECM)?

The correct choice highlights the composition of the extracellular matrix (ECM), which plays a crucial role in providing structural and biochemical support to surrounding cells. The ECM is primarily composed of structural molecules like collagen and elastin, adhesive molecules such as fibronectin and laminin, and resilient components like proteoglycans, which help maintain tissue integrity and elasticity.

Structural molecules provide strength and support to tissues, allowing them to withstand mechanical stress. Adhesive molecules facilitate cell-to-ECM interactions, promoting cell migration, proliferation, and differentiation. Resilient components, on the other hand, contribute to the cushioning properties of tissues and assist in the maintenance of tissue hydration and nutrient exchange.

In contrast, the other options do not accurately reflect the main constituents of the ECM. Neurotransmitters and hormones are primarily involved in signaling and communication within the body rather than being structural components. While structural molecules are indeed vital to the ECM, they do not encompass all the molecules present, as adhesive and resilient components are also essential for its functional integrity. Lastly, fatty acids and carbohydrates, while important biomolecules, do not represent the primary composition of the ECM itself.