Cardiac Muscle Tissue Features

Cardiac Muscle Characteristics

• Cardiac muscle has a larger number of blood vessels compared to red skeletal muscle tissue.
• Cardiac muscle cells can contract without nervous system stimulation.

Intercalated Discs

• Intercalated discs are specialized cell junctions that connect cardiac muscle cells to neighboring cells.
• They are unique to cardiac muscle tissue and have a jagged appearance due to the arrangement of cell-to-cell junctions and interlocking plasma membranes.
• Features of intercalated discs include:
  • Desmosomes that bind plasma membranes together, preventing cell separation during contractions.
  • Fascia adherens, a specialized junction that anchors actin filaments firmly to the plasma membrane.
  • Gap junctions (communicating junctions) that allow ions and small molecules to move between cells, creating a direct electrical connection between muscle cells.
• The electrical connection between cardiac muscle cells enables the stimulus for contraction (action potential) to move from one cell to another as if the sarcolemmae were continuous.