Figure 3: (A): A photomicrograph of the SAN showing one lobe of the SAN head (long arrow), and SAN arm (short arrow) Stain: H&E Obj.x10 : Oc.x10. (B) showing the SAN capsule (long arrow), the SAN septa (double arrow) and SAN arm (arrow heads) Stain: Green Masson's Trichrome Obj.x10 : Oc.x10. (C) showing the strongly PAS positive reaction of SAN capsule (short arrow), moderately PAS positive reaction of the SAN cells (long arrow) and strongly PAS positive reaction of SAN septa (arrow heads) Stain: PAS Obj.x10 : Oc.x10. (D) showing the SAN capsule (long arrow), and SAN septa (arrow heads), (E) showing the inter cellular CT.(long arrow), P. cells (arrow heads) and T. cells (short arrow) Stain: 10, 11) PAS Obj.x40 : Oc.x10. (F) showing the reticular fibers (long arrow), P. cells (short arrow) and T. cells (arrow heads) Stain: Jone's Methenamine Silver stain Obj.x40 : Oc.x10.