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.
Before the reforms of the 19th and 20th centuries, the state organisation of the Ottoman Empire was a system that had two main dimensions, which were the military administration and the civil administration. The Sultan was the highest position in the system.