From Latin capillāris 'hair-like,' from capillus 'hair,' naming the microscopic blood vessels discovered by Malpighi in 1661.
Any of the fine branching blood vessels that connect arterioles to venules, forming a network throughout the body's tissues.
From Latin capillāris 'of or resembling hair,' from capillus 'hair.' The analogy is to the hair-thin diameter of these vessels. Marcello Malpighi first observed capillaries under a microscope in 1661, confirming William Harvey's theory of blood circulation. Key roots: *kaput (Proto-Indo-European: "head