cardiac muscle (myocard)

Cardiac muscle cells (cardiomyocytes) exhibit cross-striations and centrally located nucleus. Binucleate cardiomyocytes are also occasionally seen. Around these central nuclei are the clear zone on nonfibrillar perinuclear sarcoplasm. The small granules of lipofuscin may be visible in perinuclear sarcoplasm. The intercalated discs are highly characteristic structures of cardiac muscle. The intercalated discs represent the specialized junctional complexes between cardiac muscle cells. Via intercalated discs the cardiomyocytes are connected into network. Cardiac muscle has a vast blood suply. Numerous small blood vessels and capillaries are found in the connective tissue septa and the delicate, indistinct endomysium between individual muscle cells.

Stained: modified green trichrome (collagen tissue is green, muscle tissue is red, elastic fibres and nuclei of cells are black)
Author: Mgr. Tereza Blassová, Ph.D.
Scaning of the specimen: Mgr. Yaroslav Kolinko, Ph.D.