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, which are located on sex chromosomes. Genes are segments of DNA found on chromosomes that carry information for protein production and that are responsible for the inheritance of specific traits. Genes exist in alternative forms called alleles.enes that are found on the sex chromosomes are called sex-linked genes. These genes can be on the X chromosome or on the Y chromosome. If a gene is located on the Y chromosome, it is a Y-linked gene.