| • | a widely distributed collection of both free and fixed macrophages derived from bone marrow precursor cells by way of monocytes |
| • | connective tissue – histiocytes; skin – histiocytes, Langerhans cells (?); liver – Kupffer cells; blood – monocyte; spleen, LN, bone marrow – macrophage, bone – osteoclasts; CNS – microglia; lung, GI – macrophages |
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