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Cardiac Muscle Overview

Sep 4, 2025

Overview

This lecture covers the key structural and functional characteristics of cardiac muscle tissue as seen under the microscope.

Cardiac Muscle Structure

  • Cardiac muscle tissue makes up the heart.
  • Cardiac muscle cells display striations (alternating light and dark bands).
  • Intercalated disks are unique, dark bands connecting adjacent cells.
  • Cardiac muscle cells exhibit branching.
  • Each cardiac muscle cell typically contains one nucleus (uninucleate), sometimes two (binucleate).

Cardiac Muscle Function & Location

  • Cardiac muscle is found only in the heart.
  • Muscle action is involuntary and cannot be consciously controlled.

Key Terms & Definitions

  • Cardiac muscle — muscle tissue found in the heart, responsible for pumping blood.
  • Striations — alternating light and dark bands seen in some muscle types.
  • Intercalated disks — specialized connections between cardiac muscle cells.
  • Uninucleate — having one nucleus per cell.
  • Involuntary control — not consciously controlled by the individual.

Action Items / Next Steps

  • Review the structure and function of cardiac muscle for upcoming quiz.
  • Be able to identify cardiac muscle features under the microscope.