Contribution to the study of the arterial vascularization of the sinuatrial node in sheep (Ovis aries Linnaeus, 1758)

Abstract

It was studied the arterial blood supply to the sinus node by the clearing technique of Spalteholz, after injection of the coronary arteries with gelatine solution, in the heart of 30 sheep (15 males and 15 females). There were achieved the following results: a) in the majority of the pieces (66.7%), the sinus node is nourished exclusively by branches originating from the ramus circumflexus dexter, that is only by the ramus proximalis atrii dextri (46.6%) or by this associated to the ramus distalis atrii dextri (10.0%) or to the ramus intermedius atrii dextri (10.0%); b) in some cases (33.3%), the sinus node district is supplied exclusively by the ramus proximalis atrii sinistri (23.3%) or by this associated to the ramus distalis atrii dextri ( 10.0%); c) there were observed arterial anastomosis envolving the branches that are responsables by the nutrition of the sinus node, especifically, between collateral branches from the rami proximalis atrii sinistri and proximalis atrii dextri, from the last or from that once from the ramus distalis atrii dextri; collateral branches from the rami proximalis atrii sinistri and distalis atrii sinistri, from the first only or from that second and others from the ramus intermedius atrii dextri; d) there were significant statistical differences relating the pathern of the rami proximalis atrii dextri and intermedius atrii dextri or of the ramus proximalis atrii sinistri, in the arterial supply of the sinus node when there were confronted there results and the results concerning to Merino and Corriedale sheep.