Final answer:
The disease tetanus and the sustained muscle contraction called tetanus share the same name because they both involve continuous muscle contractions.
Step-by-step explanation:
The disease tetanus and the sustained muscle contraction called tetanus share the same name because they both involve continuous muscle contractions. In the case of the disease tetanus, it is caused by the tetanus toxin produced by the bacteria Clostridium tetani. The toxin inhibits the release of neurotransmitters responsible for muscle relaxation, resulting in continuous muscle contractions. Similarly, in the context of muscle physiology, sustained muscle contractions are called tetanus when the frequency of motor neuron signaling is high enough to produce continuous contractions.