How does the toxin released by Clostridium tetani affect the body?

• A. Infects the nervous system
• B. Damages the liver
• C. Causes diarrhea
• D. Affects the kidneys

Answer: (A)

Tetanus toxin is a neurotoxin produced by Clostridium tetani. It travels from the infection site into the central nervous system and blocks the release of the inhibitory neurotransmitters GABA and glycine from inhibitory interneurons. With inhibition removed, motor neurons become overactive, leading to unopposed excitation and the characteristic rigid, spastic contractions of muscles. This effect is centered on the nervous system and not about damaging liver or kidneys or causing diarrhea, which is why the option describing effects on the nervous system best fits. The toxin’s action is essentially removing the “brakes” on motor output, often via interference with the SNARE protein machinery that releases neurotransmitters.