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

Well, the endocrine system is a body organ system that is specialized in producing these kinds of signals that are used - that accumulate in the blood and are used by cells all over the body.

内分泌系统是一种,作用于周身各器官的系统,它专门产生这些有用的信号,这些信号在血液中聚集,全身各处的细胞都可利用

耶鲁公开课 - 生物医学工程探索课程节选