Lack of relaxation between successive stimuli in sustained muscle contraction is known as Spasm, Fatigue, Tetanus, or Tonus?

Lack of relaxation between successive stimuli in sustained muscle contraction is known as tetanus. Tetanus is an acute, often-fatal disease of the nervous system that is caused by nerve toxins produced by the bacterium Clostridium tetani. This bacterium is found throughout the world in the soil and in animal and human intestines. The bacterium can also lay dormant in its spore form for years before becoming activated and develop into a regularly reproducing bacterium.The tetanus toxin affects the interaction between the nerve and the muscle that it stimulates, specifically at the neuromuscular junction. The tetanus toxin amplifies the chemical signal from the nerve to the muscle, which causes the muscles to tighten up in a continuous ("tetanic" or "tonic") contraction or spasm. This results in either localized or generalized muscle spasms. Tetanus toxin can affect neonates to cause muscle spasms, inability to nurse, and seizures. This typically occurs within the first two weeks after birth and can be associated with poor sanitation methods in caring for the umbilical cord stump of the neonate.Tetanus often begins with mild spasms in the jaw muscles (lockjaw). The spasms can also affect your chest, neck, back, and abdominal muscles. Back muscle spasms often cause arching, called opisthotonos.Sometimes the spasms affect muscles that help with breathing, which can lead to breathing problems.Prolonged muscular action causes sudden, powerful, and painful contractions of muscle groups. This is called tetany. These episodes can cause fractures and muscle tears.