I Band

I-Band - Refers to the part of the muscle cell that looks lighter under a microscope.  This area of the cell is lighter due to parallel arrangement of thinner filaments (actin), and no overlap with the thicker filaments (myosin).
  • As a muscle contracts, the I-bands will decrease in width and move closer to one another.
  1. Saladin, K. (2014). Anatomy & physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717

Related Terms

  • actin
  • myosin
  • sarcomere
  • muscle fiber


  • isotropic
  • I band
  • I-Band