Tetanus is a type of infection specifically related to the surgical context, caused by Clostridium tetani. It can invade the human body through skin or mucosal wounds, and flourishes in an anaerobic environment. The toxin produced by the tetanus bacterium primarily invades the neurons of the human nervous system, causing muscle spasms such as lockjaw, episodic spasms, and compulsive spasms, with muscles like the lumbar, back, and abdominal muscles being mainly affected. The incubation period of tetanus is usually seven to eight days, with the shortest being within 24 hours and the longest can extend to several months or even years.