CARACTERíSTICAS MACRO Y MICROSCóPICAS DEL CORAZóN Y GRANDES VASOS DEL COIPO (Myocastor coypus, Molina) DE DIFERENTES EDADES

macro and microscopic aspects of the heart and great vessels of coypu (myocastor coypus, molina) of different ages were studied. the anatomical characteristics of some superficial veins for potential application in venipuncture were also investigated. 44 coypu of both sexes, including adults, prepuberals, newborns and 120 day gestation fetuses were used. the heart and great vessels of 18 adults and prepuberals, and of 14 newborns, and the cephalic and lateral and medial saphenous veins of all adults and prepuberals were dissected, measured and photographed. samples of heart and aorta of animals of all ages were fixed and processed by conventional histological methods. sections were stained with hematoxilin-eosin, picrosirius red, verhoeff′s iodine-iron hematoxylin and weigert′s resorcin-fuchsin with and without oxone. the heart and great vessels were similar to those of other rodents, although some proper characteristics could be observed. the relative weight of the heart was 0.93 to 1.03 %. the cephalic and lateral saphenous veins were found appropriate for venipuncture. in adults and prepuberals, fibers of the collagenous and elastic systems were similar to those of other rodents. in fetuses, when compared with newborns, differences in amount and distribution were observed, mostly in fibers of the elastic system