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.
Your Guide to Sexually Transmitted Diseases. Sexually transmitted diseases, commonly called STDs, are diseases that are spread by having sex with someone who has an STD. You can get a sexually transmitted disease from sexual activity that involves the mouth, anus, vagina, or penis.