Anatomy of the Atrioventricular Node in the Heart of Cat

Tadjalli, M., Ghazi, S.R. and Shahri, A.B. 1999. Anatomy of the atrioventricular node in the heart of cat. J. Appl. Anim. Res., 15: 35-40. An anatomical and, histological study was conducted on atrioventricular node (AVnode) often cats (Felis catus). The AV node was located beneath the endocardium at caudoventral portion of the lower right side of interatrial septum, anterior to the coronary sinus above the septal cusp of the tricuspid valve. It was irregular elongated, oval in shape and measured 1.70±0.16 mm in length, 0.45±0.04 mm in width and 0.70±0.06 mm in thickness in male cats, where as, in female cats it measured 1.21±0.03 mm in length, 0.26±0.03 mm in width and 0.53±0.04 mm in thickness. Histologically, the AV node consists of specialized myocardial fibers arranged in the form of peculiar, irregular interlacing bundles. The cells lacked in glycogen and no intercalated discs were observed between them. At the posterior of the AV node there were nerve fibers, parasympathetic ganglia and also a number of arteriols which supplied the node.