Coronary arteries of the European bison (Bison bonasus)

Abstract

Background: The European bison (Bison bonasus) is an endangered species. More information on its anatomy is needed as only few studies have been published. This study is the first report on the morphology of the coronary vessels. Given the anatomical similarity between the European bison and other ruminants, the results of this study can be applied to other species, including endangered ones.

Results: The study was conducted on 70 hearts of European bisons of both sexes, aged 5-20 years, with an average body weight of 449 kg. A distinct view of subepicardial arterial vessels was obtained by filling them with dyed synthetic latex (LBS 3060) and Plastogen G. There was a division of the common trunk of the left coronary artery into the interventricular paraconal branch and the left circumflex branch in 63 individuals (90 %). In five individuals (7.1 %), the presence of a third vessel, which was a branch of the interventricular septum, was observed. There was a lack of a common trunk in two individuals (2.9 %). Ramifications of the interventricular paraconal branch to the wall of the left ventricle were significantly larger than those to the wall of the right ventricle. In 17 individuals (24.3 %), the right coronary artery extended into the subsinuosal interventricular branch.

Conclusion: The blood supply to the heart in bisons is provided by the left and right coronary arteries. In all the studied specimens, the left coronary artery was better developed than the right coronary artery.

Fig. 1

Branches of the left coronary artery. 1 the common trunk of the left coronary artery, 2 the paraconal interventricular branch (the descending part), 3 the left circumflex branch, 4 the left conal branch, 5 the proximal branch of the left atrium, 6 the proximal branch of the left ventricle and 7 the branch of the left ventricular border. Base of the heart; female, 7-years-old, body weight 430 kg

Fig. 2

Branches of the left coronary artery (the auricular surface) in a European bison. a The separate origins of the proximal collateral branches (female, 7 years, 430 kg), b single proximal collateral branch (female, 15 years, 450 kg). 1 The paraconal interventricular branch (the descending part), 2 the paraconal interventricular branch (the ascending part), 3 the left circumflex branch, 4 the proximal collateral branches of the left ventricle, 5 the intermediate collateral branch of the left ventricle, 6 the distal collateral branch of the left ventricle, 7 the left conal branch and 8 the collateral branches of the right ventricle

Fig. 3

Branches of the left circumflex branch in a European bison. 1 the left circumflex branch, 2 the proximal branch of the left ventricle, 3 the branch of the left ventricular border, 4 the distal branch of the left ventricle, 5 the paraconal interventricular branch (the descending part), 6 the paraconal interventricular branch (the ascending part). Left ventricular border, male, 13-years-old, body weight 420 kg

Fig. 4

Branches of the right circumflex branch in a European bison. 1 the right circumflex branch, 2 the right conal branch, 3 the branch of the right ventricular border, 4 the intermediate branch of the right atrium, 5 the distal branch of the right ventricle, 6 the paraconal interventricular branch (the descending part) and 7 the intermediate collateral branch of the left ventricle. Right ventricular border; male, 8-years-old, body weight 570 kg