(also pacinian corpuscles), sensory nerve endings (receptors) that perceive changes in pressure in the tissues of man and other mammals. They are found chiefly in the skin, mesentery, and connective membranes of the internal organs. Pacini’s corpuscles are between 0.5 and 3 mm in size. They were described in detail in 1835 by the Italian scientist F. Pacini. Each corpuscle is made up of a peripheral capsule, which consists of concentric layers of endothelioid cells, and a central part, which consists of cells of unknown origin (fibrocytes or neuroglial cells) and the branches of nerve fibers that are embedded therein. Pressure causes the layers to shift, thus deforming the axon and producing a nerve impulse.