Answer
There is loss of stimulation to skeletal muscles
When a skeletal muscle loses stimulation because injury/infection impairs the function of a somatic motor neuron to the muscle, the muscle will initially lose tone and in time will undergo denervation atrophy with decrease in muscle fiber diameters and eventual paralysis.
The diaphragm is the chief muscle of respiration. When its motor neurons are damaged by the polio virus,
the muscle gets weaker and atrophies. When this occurs, the diaphragm is unable to contract and the patient eventually suffers respiratory failure.
Work Step by Step
The polio virus usually enters the body from feces or contaminated water. It attacks ventral motor neurons and causes inflammation in the gray matter of the spinal cord (SC). Early symptoms are fever, headache, muscle pain, weakness, loss of somatic reflexes, and extreme lethargy. The patient dies from respiratory failure or cardiac arrest.
