The macroanatomy of coronary arteries in donkeys (Equus asinus L.)

The aim of this study was to define the arteries that supply the cardiac muscle in donkeys with regard to their course and possible variations. Six hearts belonging to donkeys of different age and sex constituted the material of the study. Following exposition of the arteries by means of injection of latex coloured with Rotring ink to a. coronaria sinistra and a. coronaria dextra, dissection was performed. The arterial vascularization of the heart in donkeys was determined to be supplied by a. coronaria sinistra and a. coronaria dextra which originate from the aorta. A. coronaria sinistra, measured to be larger than a. coronaria dextra, was determined to have its origin at the aorta, at the level of the free border of valvula semilunaris sinistra, and to extend between truncus pulmonalis and auricula sinistra. The mentioned artery was detected to give off two branches, namely, ramus interventricularis paraconalis and ramus circumflexus sinister which extend in sulcus interventricularis paraconalis and sulcus coronarius, respectively. However, a. coronaria dextra was determined to have its origin at the beginning of the aorta, at the level of valvula semilunaris dextra, and to extend to margo ventricularis dexter between truncus pulmonalis and auricula dexter. This study has revealed ramus interventricularis subsinuosus and ramus circumflexus dexter to intercommunicate by means of anastomosis and to form a. coronaria dexter. Examination of material revealed the absence of anastomosis between r. circumflexus sinister and r. circumflexus dexter. Branches named rami septales, originating from ramus interventricularis paraconalis and ramus interventricularis subsinuosus were determined to supply septum interventriculare. Ramus proximalis atrii sinistri was determined to have its origin at ramus circumflexus sinister whereas ramus proximalis venriculi dextri was determined to stem from the beginning of a. coronaria dextra in the material of this study. However, examination of the cranial and caudal branches of ramus coni arteriosi, revealed the cranial branch to be ramus proximalis ventriculi dextri in a cadaver.