Question

multiple choice question
the reproduction of fibroblasts and smooth muscles during injury repair is triggered by which of the following?

• erythropoietin
• platelet - derived growth factor
• histamine
• serotonin - releasing factor

Explanation:

To solve this, we analyze each option:

• Erythropoietin stimulates red blood cell production, not fibroblast/smooth muscle repair.
• Platelet - derived growth factor (PDGF) is known to trigger the proliferation of fibroblasts and smooth muscle cells during tissue repair (injury repair) as it promotes cell growth and division in the context of wound healing.
• Histamine is involved in allergic responses and inflammation - related vasodilation, not in triggering fibroblast/smooth muscle reproduction for repair.
• Serotonin - releasing factor is related to serotonin regulation, not to injury - related cell reproduction of fibroblasts and smooth muscles.

Answer:

B. Platelet - derived growth factor