Interesting Anatomy Etymology – Capillary February 14, 2019Anatomy, Infographicanatomy, capillary, etymology, vesselphysioweb Capil-Hairy ‘Capillary’ comes from the Latin ‘capillaris’ – “relating to the hair or any structure as fine as a hair”. Early anatomists thought capillaries looked hair-like. Capillary diameters are actually smaller than hair. Red blood cells can only travel through them one at a time. View more anatomical terms with interesting origins.