Study On Anatomical Structure Of Artery And Vein In Yak Hearts

The anatomical structure of arteries and veins of 38 yak hearts was observed with anatomical dissection and injection-corrosion methods. The results are as follows:1. The blood supplying the hearts is the left and right coronary arteries. There is the accessory coronary orifice in the left and right aortic sinuses. The terminal part of the left coronary stem divides into anterior descending branch, circumflex branch and diagonal branch. The diagonal branch was found in 79 per cent of the 19 specimens. The anterior descending branch gives off the left anterior ventricular branches, right anterior ventricular branches and anterior septal branches. The circumflex branch gives off the left anterior ventricular branches, left marginal branch, left posterior ventricular branches and the left atrial branches. The posterior descending branch is the continuation of the circumflex branch and gives off the left and right posterior ventricular branches, and the posterior septal branches. The right coronary artery gives rise to the right anterior ventricular branches, right marginal branch, right posterior ventricular branches and the right atrial branches. The sinus node artery comes off the proximal part of the circumflex branch in 97.4 per cent of the 38 specimens, in 2.6 per cent off the right coronary artery. The atrioventricular node artery originates from the curve of the circumflex branch of the left coronary artery and the posterior descending branch. Four types of the arterial branches in the ventricular wall are the epicardial branches, the arborized branches, the straight branches and the papillary muscle branches. The type of distribution of the coronary arteries is a preponderance of the left coronary artery. The anastomoses were observed among the branches of the coronary arteries.2. The veins of the heart are divided into superficial and deep veins. The heart is drained by the coronary sinus, the anterior cardiac veins and the smallest cardiac veins. The tributaries of coronary sinus are constantly the great and middle cardiac veins, the azygos vein and the posterior veins of the left ventricle. The left anterior ventricular veins, right anterior ventricular veins, left atrial veins, left marginal vein and the anterior septal veins open into the great cardiac vein. The middle cardiac vein receives the left and right posterior ventricular veins, and the posterior septal veins. There are valves in the superficial veins. There are frequent anastomoses in the veins. The anterior third to two thirds of the septum is drained by the anterior septal veins opening into the great cardiac vein; the posterior second to two thirds of the septum is drained by the posterior septal veins opening into the middle cardiac vein.3. A greater vein accompanies an artery. Two veins accompany an artery in the some ventricular branches, the septal branches and ventricular wall branches. The veins are larger in caliber than that of accompanying arteries. The great cardiac vein with the anterior descending and circumflex branches of the left coronary artery form arteriovenous trigon which present in 80 per cent of the 10 specimens.