Left Ventricles of the Mature Camel Heart (Camelus dromedaries) with Special References to the Structure and Distribution of the Purkinje Cardiomyocytes:Microanatomy

Abstract

The present investigation was performed to clarify the histological features of the left ventricles in the heart of the mature dromedary camel. This investigation was carried out on the left ventricles of six healthy mature camels. Microscopically, the left ventricles is consisted of three major layers or tunics; the internal endocardium, the middle myocardium, and the external epicardium. The endocardium is consisted of three layers; the endothelial layer of simple squamous epithelium, sub-endothelial layer of loose connective tissue and the sub-endocardial layer that connecting the endocardium with the myocardium and housing bundles of the purkinje cardiomyocytes; purkinje fibers. The myocardium, is the middle layer of the ventricular wall, is sandwiched between an outer epicardium, that covers the ventricular wall, and an inner endocardium, that lines the chamber, containing two bundles of cardiac fibers; the working cardiac myocytes (myocardiocytes) and the purkinje bundles. The epicardium is the outer most layer of the ventricular wall. This layer is a relatively thin in comparison with the myocardium and is consisted of a sub-epicardial layer of loose connective tissue which housing many blood vessels, lymph vessels, nerves and adipocytes and mesothelium of simple squamous epithelium.

Histological study on the heart ventricle of Egyptian bovines (<i>Bos aegyptiacus</i>)

“…Also, Kawano et al (2003) demonstrated the presence of more autonomic nerves in the subendocardial area than in the subepicardial area of the human ventricle. The intramural Purkinje fibers, in this study, were seen among the myocardium that confirms the ramification of Purkinje fibers within endocardium and myocardium as recorded by Ryu et al (2009) in sheep and Ghonimi et al (2014) in camel but, these fibers were not identified in the heart of human (Durrer et al, 1970;Oosthoek et al, 1993). The presence of intramural Purkinje fibers in the myocardium results in a more efficient excitation of the ventricles compared with the absence of intramural Purkinje fibers (Oosthoek et al, 1993;Tranum-Jensen et al, 1991) as they prevent intercyclic pre-excitation of the ventricular myocardium.…”