Final answer:
Cytokines are the protein molecules that stimulate cells to divide and heal a wound such as a skinned knee. They act as autocrine or paracrine factors to promote the proliferation of cells and play a critical role in the body's resistance to disease.
Step-by-step explanation:
When you fall down and skin your knee, the special protein molecules that will stimulate cells to divide and heal your wound are Cytokines. Cytokines are glycoproteins that act as autocrine or paracrine factors, which means they operate at the site of tissue damage to stimulate the proliferation of progenitor cells. They also play a critical role in both nonspecific and specific resistance to disease. Among cytokines, there are colony-stimulating factors and interleukins, both of which are vital for the healing process.
For example, during wound healing, cytokines such as transforming growth factor-beta (TGF-β) and interleukins are released into the damaged area to promote tissue repair by stimulating the migration and division of cells necessary for tissue regeneration. Thus, the production and action of cytokines are crucial for the successful healing of a skinned knee.