The anatomy of the atrioventricular bundle in the heart of camels (Camelus dromedarius)

Abstract

The anatomy and histology of the atrioventricular bundle (AVB) was studied in the heart of six camels (Camelus dromedarius). The trunk of the atrioventricular bundle (bundle of His) was a direct continuation of the atrioventricular (AV) node with no sharp line of demarcation between the node and the bundle. The atrioventricular bundle ran through the fibrous trigone and entered the lower part of the interventricular membranous septum, beneath the right endocardium, then lay over or slightly to the side of the centre of the muscular interventricular crest. The AVB of camels measured 4.12 +/- 1.00 mm in length, 3.66 +/- 1.13 mm in width and 1.13 +/- 1.85 mm in thickness, its maximum sectional area being 12.68 +/- 6.13 mm2. Histologically, the AVB in the heart of camels comprised multiple strands of Purkinje cells separated by collagen fibres and surrounded by connective tissue. It resembled that in human beings and dogs except that, in camels, intercalated discs were present at the intercellular connections in the AVB.

Anatomy of the Atrioventricular Node in the Heart of Cat

“…These AV nodal cells were smaller and paler than ordinary myocardial fibers (Fig. 1) and therefore, were similar to those of dogs (James, 1964), cattle (James, 1965), horses (Bishop and Cole, 1967), rabbits (James, 1967) and camels (Ghazi and Tadjalli, 1995). The cells of the node lacked glycogen and intercalated discs were not observed between them which is similar to that in other animals.…”

“…At the posterior part of the AV node of cats, there were many nerve fibers and ganglia, similar to that of dogs (James, 1964) and camels (Ghazi and Tadjalli, 1995). These ganglia were characteristically ' parasympathetic and were not found within the substance of the AV node.…”

“…dogs (James, T964), horses (Bishop and Cole, 1967) and camels (Ghazi and Tadjalli, 1995). However, in rabbits, because of the big coronary sinus, it is shifted more anteriorly (James, 1967).…”

“…Many other researchers have investigated its anatomy, light microscopic appearance, ultrastructure and its blood supply in different species (James, 1964;1965;1967;Bishop and Cole, 1967;Szabo et al, 1986;Ghazi and Tadjalli, 1995). No information is yet available on the anatomical and histological details of this structure in the heart of cats and therefore, the present study was undertaken to define these details.…”

Anatomy and Histology of the Atrio-Ventricular Bundle in the heart of Goats (Capra hircus)

“…Since then the anatomy and histology of the AVB of human beings (James, 1970) and various animals (Ghazi and Tadjalli, 1993;Ghazi et al, 1998) have been studied. However, no information is yet available on the anatomy and histology of the AVB of goats.…”