MICROANATOMICAL STUDIES ON THE MODERATOR BAND (TRABECULA SEPTO MARGINALIS) OF HORSES (EQUUS CABALLUS)

The moderator bands from six adult horses over two years of age were utilised for histological studies. The moderator band (trabecula septomarginalis) was composed of an outer thick endocardial covering, Purkinje fibres, ordinary myocardial fibres, blood vessels and nerves. The endocardium was thick and consisted of an endothelial covering and an underlying connective tissue of collagen, elastic and a few reticular fibres. The Purkinje fibres were large, irregular cells with centrally placed nuclei. It was present either in the myocardium or in the subendocardium. The myocardial fibers were striated and had a centrally placed nuclei. The intercalated disks were noticed in both myocardial fibers and Purkinje fibres. Blood vessels of various sizes and nerve fibres were also noticed.