Question

ALS (amyotrophic lateral sclerosis) is a disease that destroys nerve cells that control skeletal muscle activity. Without neural stimulation, skeletal muscles eventually waste away and mobility is impossible. In other words, skeletal muscles __________.

A) become flaccid
B) become atrophied
C) lose muscle tone
D) lose muscle tone and become flaccid

Answer 1

In ALS, skeletal muscles become atrophied due to the degeneration of motor neurons that control voluntary muscle movement, leading to muscle weakness, lack of coordination, and eventual paralysis. ALS is a neurodegenerative disease characterized by hardened nerve pathways in the spine that fail to stimulate skeletal muscles correctly.

Step-by-step explanation:

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that mainly affects the motor neurons responsible for controlling voluntary muscles. Over time, as the disease progresses, these motor neurons degenerate and lose their ability to send signals to the muscles, causing muscle weakness, lack of coordination, and eventually leading to muscle atrophy and paralysis. Because the affected neurons are those that connect to muscles and signal them to contract, the skeletal muscles become atrophied due to lack of stimulation and use.

In the context of the student's question, the in ALS, skeletal muscles become atrophied. This occurs because the disease causes the lateral portion of the spine to harden, blocking the nerve signals to the muscles, leading to decreased muscle mass and strength over time. As ALS progresses, patients may maintain cognitive function but gradually lose the ability to move, speak, swallow, and eventually breathe without assistance, necessitating the use of technologies like brain-computer interfaces for communication.