Etiology and Pathogenesis l、decreased production:生成不足 Stem cell Committed cell Developmental pathway Phase 1 Phase 2 Phase 3 Ribosome synthesis Hemoglobin accumulation Ejection of nucleus 造血干细胞 红系祖细胞 早幼红细胞晚幼红细胞 幼红细胞 网织红细胞红细胞 红细胞生成Etiology and Pathogenesis 1、decreased production: 生成不足