This is the myocyte
which is spindle-shaped with a nucleus that is centrally placed. The
myocyte is the muscle fiber. Its sarcoplasm has longitudinal
striations which are indistinct but no transverse striations. The
length of a smooth muscle cell or muscle fiber is about 15-500 Ám.
The smooth muscle cell contains myofibrils
containing myofilaments actin and myosin disposed in a
haphazard manner, hence the smooth appearance of the muscle under the
microscope. It has numerous mitochondria and sarcoplasmic
reticulum. It possesses yellow pigment granules. Muscle fibers
are attached to each other by a cement like substance.