histology of the heart

•  Epicardium / Visceral epicardium - a thin, serous membrance forming the smooth outer surface of the heart
• Myocardium - thick, middle layer of the heart, composed of cardiac muscle cells.
• Endocardium - the smooth inner surface of the heart, which consists of simple squamous epithelium over a layer of connective tissue.

   
• Trabeculae carnae - it is composed of ridges and columns of the cardiac muscles that modifies the surfaces of the interior walls of the ventricles.

   
• CARDIAC MUSCLE - these are elongated, branching cells that contain one, or occasionally two, centrally located nuclei

   
• Intercalated disks - are highly folded, and the adjacent cells fit together, greatly increasing contact between them and preventing cells from pulling apart.
• Gap junctions specialized cell membrane structures in the intercalated disks that allows cytoplasm to flow freely between cells.

   
• HEART WALL - composed of three layers of tissue;