The contraction produced can be described as a twitch, summation, or tetanus, depending on the frequency of action potentials. In skeletal muscles, muscle tension is at its greatest when the muscle is stretched to an intermediate length as described by the length-tension relationship. Smooth and cardiac muscle contractions are myogenic and can be modulated by the autonomic nervous system.
Citation: Pray, L. (2008) Sex-linked diseases: the case of Duchenne muscular dystrophy (DMD). Nature Education 1(1):132. Prenatal diagnostic testing can now determine whether a fetus carries a debilitating or fatal sex-linked mutation.
Sex-linked traits are genetic characteristics determined by genes located on sex chromosomes. Sex chromosomes are found within our reproductive cells and determine the sex of an individual. Traits are passed on from one generation to the next by our genes.