Which feature is unique to cardiac muscle histology and not found in skeletal muscle?

Which feature is unique to cardiac muscle histology and not found in skeletal muscle?

• A. Intercalated Discs
• B. Centrally Located Nuclei
• C. Striations
• D. Endomysium

Answer: (A)

Intercalated discs are specialized junctions that connect cardiac muscle cells (cardiomyocytes) end-to-end. They house desmosomes for strong mechanical attachment and gap junctions for direct electrical communication. This arrangement lets ions pass quickly between cells, so the heart contracts as a coordinated unit rather than as isolated fibers. Skeletal muscle lacks these intercellular junctions, so it cannot achieve that same rapid, synchronized electrical coupling across cells. Other features like striations and connective tissue around fibers (endomysium) appear in both muscle types, and the location of nuclei differs but is not unique to cardiac tissue.

Intercalated discs are specialized junctions that connect cardiac muscle cells (cardiomyocytes) end-to-end. They house desmosomes for strong mechanical attachment and gap junctions for direct electrical communication. This arrangement lets ions pass quickly between cells, so the heart contracts as a coordinated unit rather than as isolated fibers. Skeletal muscle lacks these intercellular junctions, so it cannot achieve that same rapid, synchronized electrical coupling across cells. Other features like striations and connective tissue around fibers (endomysium) appear in both muscle types, and the location of nuclei differs but is not unique to cardiac tissue.