Muscle

Interventricular septum, Heart, Sheep

Survey your section under low power. Identify the endocardium(on both sides). Bundles of Purkinje fibres(specialized cardiac fibres) in transverse section are seen on one side. Examine the Purkinje fibres under high power; they are arranged as groups of four or five fibres which are in intimate contact. These groups of Purkinje fibres are separated by connective tissue. The nucleus of the fibre is centrally located. The empty-looking space in the perinuclear zone represents the site where glycogen accumulations was washed out during slide preparation. Scattered amongst the muscle fibres are densely nucleated oval patches that represent protozoal parasites infesting the heart of the sheep.