original c. 1950's american vintage medical human anatomical model heart fabricated by or for merck & co., inc., whitehouse station, nj. the diminutive molded plastic heart model divides into anterior and posterior sections to access its pumping chambers and valves. the color-coded model does show some surface wear and/or discoloration consistent with age. the original form-fitting display base was removed/lost long ago. measures approximately 6 1/2 x 4 inches.