Moderator Bands (Trabecula septomarginalis) of Mature Buffalo (Bos bubalis L.) with Special Emphasis on the Structure and Distribution of the Purkinje Cardiomyocytes: Histological and Histochemical

Abstract

Ten hearts of mature healthy Buffalo (Bos bubalis L.) were employed to investigate the histological and histochemical structures of the moderator bands. Hearts were gently dissected and the moderator bands were collected. The specimens were processed histologically and subjected to different stains. Grossly, the moderator band (Septomarginal trabeculae) was a single muscular band that was found only in the right ventricle of the buffalo heart. It extended from the interventricular septum to the free ventricular wall especially at the base of the papillary muscle, crossing and passing through the ventricular cavity. Histologically, the moderator band was invested in a dense capsule of connective tissue, endocardium that is mainly consisting of three layers; the endothelial layer of simple squamous epithelium, subendothelial layer of loose connective tissue and the subendocardial layer that connects the endocardium with myocardium. Internally, about 4/5 of the core, myocardium is of the cardiac muscle fibers that arranged in bundles of one direction while only about 1/5 is lodged by purkinje cardiomyocytes that were arranged in bundles distributing mainly in two areas within the moderator band; the subendocardial layer beneath the subendothelial connective tissue and myocardium in between the cardiac myocytes bundles. Centrally, a medium-sized artery of thick wall and a very distinct internal elastic lamina was observed running at the center of the band myocardium and is surrounded with the cardiac myocytes bundles.

Histological and anatomical variations of septomarginal trabecula in bovine hearts

“…In the present study, the septomarginal trabeculae of the bovine heart were a single muscular band that extends from the interventricular septum to the opposite right ventricular wall. It is in accordance with findings in studies using others species, such as pigs (Ateş et al, ; Gulyaeva & Roshchevskaya, ), dogs (Bombonato et al, ; Cope, ), camels (Ghonimi, Abuel‐Atta, Bareedy, & Balah, ), equines (Ghonimi et al, ; Halıgür & Dursun, ; Sathyamoorthy & Ramesh, ) and humans (Bandeira et al, ; Kosiński et al, ; Mamatha et al., ; Reig, Alberti, & Petit, ; Rocha et al, ).…”

“…Studies on the location of moderator bands and the distribution of conductive cells in those structures have been conducted in humans (Bandeira et al, ; Chaudhary, Bharti, & Deshpande, ; Kosiński et al, ; Mamatha, Shenoy, D´Souza, Prasana, Sumalatha, Shenoy, D´Souza, Prasanna, & Sumalatha, ; Rocha et al, ; Shenoy, Lucas, Vinay, & Ramos, ) and several animal species, including goats (Leão et al, ), sheeps (Ansari, Ho, & Anderson, ), pigs (Bojsen‐Moller & Tranum‐Jensen, ; Gulyaeva & Roshchevskaya, ), dogs (Bombonato et al, ), equines (Bombonato et al, ; Sathyamoorthy & Ramesh, ), buffalos (Ghonimi et al, ) and ostriches (Parto, Tadjalli, & Ghazi, ). Meanwhile, not many studies involving morphology, tissue morphological composition and possible variations of the septomarginal trabecula were performed.…”

Histomorphometry and Stereological Study of Septomarginal Trabecula in Pig’s Heart

“…In this study, the histological examination of the ST revealed the presence of connective tissue, cardiac muscle fibers, blood vessels, and Purkinje cells in pig heart samples, in agreement with the histological description of the trabeculae in other animal species and in humans 11,16,17,19,32,[43][44][45][46] . It was also evidenced a variation in Purkinje fibers distribution and disposition, besides the proportion between the striated cardiac and connective muscle tissues between the samples.…”

Morphology of septomarginal trabeculae in Hatay mountain gazelle (Gazella gazella)

“…In the literature, it has been reported that the right septomarginal trabecula extends between the septum—outer wall (Evans & De Lahunta, 2013; Nascimento et al, 2019; Ravindran & Victor, 1982) septum—anterior papillary muscle (Ghonimi et al, 2015; Kosinski et al, 2010; Leao et al, 2010; Nascimento et al, 2019; Raghavendra et al, 2013), anterior papillary muscle—outer wall (Arıncı & Elhan, 2014; Ateş & Çakır, 2010; Cope, 2016b; Evans & De Lahunta, 2013), and septal papillary muscle—anterior papillary muscle (Ates et al, 2017; Gulyaeva & Roshchevskaya, 2012; Perez et al, 2018). In our study, it was determined that the right septomarginal trabecula extended between the septal papillary muscle and the anterior papillary muscle.…”