These are about 8 nm in diameter and, being the thinnest of the cytoskeletal filaments, are also called microfilaments. (In skeletal muscle fibers they are called thin filaments.) Some functions of actin filaments: 1  form a band just beneath the plasma membrane that.  provides mechanical strength to the cell.
The microfilaments are arranged so that the fibers appear to have stripes (striations) in them. These are also called voluntary muscles.. Smooth muscle is involuntary, and is not under conscious control; the muscles in your digestive system are smooth muscles.The cells are individual and are found in sheets instead of long fibers. (Cardiac muscle has characteristics of both, but are not referred to in the question).here skeletal muscle is voluntary, cardiac muscle is autorhythmic (beats involuntarily; generates its own action potentials). 3. Smooth muscle: refers to the muscles that are controlled involuntarily by the brain, like those attached to the base of hair follicles or in the walls of the gastro-intestinal tract.
Smooth muscle is also sometimes known as Involuntary muscle due to our inability to control its movements, or Unstriated as it does not have the stripy appearance of Skeletal muscle. Smooth muscle is found in the walls of hollow organs such as the Stomach, Oesophagus, Bronchi and in the walls of blood vessels.ardiac muscle (heart muscle). This type of muscle is found solely in the walls of the heart. It has similarities with skeletal muscles in that it is striated and with smooth muscles in that its contractions are not under conscious control. However this type of muscle is highly specialised.