GENERAL HISTOLOGY

Detailed explanation-1: -Smooth muscle cell contraction squeezes the cell from every direction since the myofibrils are not arranged in a pattern as in other muscles. Hence, light and dark bands are absent in smooth muscles.

Detailed explanation-2: -Smooth muscle is an involuntary non-striated muscle, so-called because it has no sarcomeres and therefore no striations (bands or stripes).

Detailed explanation-3: -Smooth muscle has no light and dark bands, so they are known as striated muscle tissue.

Detailed explanation-4: -The light bands contain actin and are called I-band or Isotropic band, whereas the dark band called ‘A’ or Anisotropic band contains myosin. Hence called striped muscles due to the presence of striations. Hence Myofibrils show dark and light bands in Cardiac muscles and striped muscles.