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.
Muscle tissue varies with function and location in the body. In mammals the three types are: skeletal or striated muscle; smooth or non-striated muscle; and cardiac muscle, which is sometimes known as semi-striated.n vertebrates, there is a third muscle tissue recognized: 1  Cardiac muscle (myocardium), found only in the heart, is a striated muscle similar in structure to skeletal muscle but not subject to voluntary control.
any muscle, including all of the skeletal muscles, in which the fibers are divided by bands of cross-striations (stripes) as a result of overlapping of thick and thin myofilaments. Contractions in such muscles are voluntary. The heart, a striated involuntary muscle, is an exception. Cardiac muscle is often placed in its own category because it has microanatomical and contraction physiological characteristics very different from those of most striated muscle. Also called skeletal muscle, voluntary muscle.