Disorders of Muscle (Additions to Supplement)

spasticity (excessive tone) can be caused by:

Tetanus – bacterial (Clostridium teteni) toxin blocks glycine release from inhibitory neurons, thus creating excessive tone (tetanus) in muscles
Cholinesterase inhibitors (e.g., neostigmine; organophosphate pesticides) – inhibit breakdown of ACh leading to overstimulation (ACh to build up at NMJ ? keeps channels open longer)

flaccid paralysis (loss of tone) can be caused by:

Curare – blocks ACh receptors on skeletal muscle resulting in flaccid paralysis
Damage to lower motor neuron (ventral horn or root)
Stroke in area of brain that creates motor tone