The central cavity in the picture is a blood vessel with endothelium, surrounded by a very cellular connective tissue. 图片中央有一纵切的小血管，内衬内皮，周围被细胞成分较多的结缔组织围绕。
The branch of biology that deals with heredity and the cellular components,particularly chromosomes,associated with heredity. 细胞遗传学，研究遗传和细胞成分的生物学分支，特别是与遗传有关的染色体。
