| [Visitor (112.0.*.*)]answers [Chinese ] | Time :2022-09-25 |  Microscopic visualization of a large number of solid cell cords formed by endothelial cell proliferation and dilated capillaries, growing vertically to the wound, and with arterioles as the axis, forming a loop-like curved capillary network around it. There are many new fibroblasts around the capillaries, in addition to a large number of exudates and inflammatory cells. Inflammatory cells are often dominated by macrophages, and there are many neutrophils and lymphocytes in varying numbers, so granulation tissue has anti-infective function.
Macrophages secrete PDGF, FGF, TGF-β, IL-1 and TNF, plus platelets released by platelets during wound clotting to further stimulate fibroblasts and capillary hyperplasia. Macrophages and neutrophils can engulf bacteria and tissue fragments, these cells release a variety of proteolytic enzymes after destruction, can decompose necrotic tissue and fibrin, granuloma tissue capillary endothelial cells also have phagocytosis, and have a strong fibrinolytic effect.
Some fibroblasts in granulation tissue contain myofilaments in the cytoplasm, which in addition to fibroblast function, also has the function of smooth muscle cells, called myofibroblasts. |
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