Question

When a muscle undergoes atrophy in response to disuse

A. there is a reduction in capillary networks.
B. the size of actin and myosin filaments decreases.
C. the muscle gets smaller.
D. all of the above.

Answer 1

When a muscle undergoes atrophy due to disuse, there is a reduction in capillary networks, a decrease in the size of actin and myosin filaments, and an overall reduction in muscle size, meaning the correct answer is D. all of the above.

Step-by-step explanation:

When a muscle undergoes atrophy in response to disuse, the answer is D. all of the above. This means that:

• There is a reduction in capillary networks, which can impair the delivery of blood and nutrients to the muscle tissue.
• The size of actin and myosin filaments decreases, leading to a reduction in the muscle's ability to contract and generate force.
• The muscle gets smaller, a visible and palpable decrease in muscle mass.

Inactivity and conditions like sarcopenia (age-related muscle atrophy) lead to a loss in muscle mass, strength, and functional capacity. It's important to note that while atrophy due to disuse can be reversible to some extent through exercise, sarcopenic atrophy is largely irreversible.