The innate immune system composed of neutrophils and macrophages; these are cells that are crawling around your body all the time ready to eat bacteria.

它由嗜中性粒细胞和巨噬细胞构成,这些细胞不断在周身蠕行,准备吞噬细菌

耶鲁公开课 - 生物医学工程探索课程节选