Final answer:
Black widow venom contains latrotoxins that enhance acetylcholine release at neuromuscular junctions, causing pain and muscle cramps, but it does not cause tetanus. Tetanus, caused by Clostridium tetani, blocks inhibitory neurotransmitters in the CNS leading to muscle spasms.
Step-by-step explanation:
The venom of a black widow spider does not result in tetanus, which is a bacterial infection caused by Clostridium tetani producing a potent toxin called tetanospasmin or tetanus toxin (TeNT). This neurotoxin binds to inhibitory interneurons in the central nervous system (CNS) and blocks the release of inhibitory neurotransmitters like glycine and gamma-aminobutyric acid (GABA), responsible for muscle relaxation. By inhibiting these neurotransmitters, the toxin leads to sustained muscle contraction and spasms, known as spastic paralysis. Conversely, black widow spider venom, which contains latrotoxins, affects the neuromuscular junction by causing the massive release of acetylcholine, leading to pain, muscle cramps, and other symptoms. The specific action that leads to symptoms associated with a black widow bite is the enhancement of acetylcholine release at the neuromuscular junction.