In anatomical terms, an afferent is a vessel or other conduit that brings substances towards a central area, which is often a major organ like the brain or the heart. It is the opposite of an efferent vessel, which carries substances away from these central locations.
The system of imperial units or the imperial system (also known as British Imperial) is the system of units first defined in the British Weights and Measures Act of 1824, which was later refined and reduced.
British Imperial System - a system of weights and measures based on the foot and pound and second and pint. British system, English system. system of weights and measures - system of measurement for length and weight and duration. avoirdupois unit - any of the units of the avoirdupois system of weights.