Older adults tend to lose muscular strength because muscle cells
a. get larger in size.
b. attach to the nervous system i.
c. increase in number.
d. get smaller in size.
The Correct Answer And Explanation is:
Correct Answer: d. get smaller in size.
Explanation:
As people age, it is common to experience a decline in muscle strength, a condition referred to as sarcopenia. Sarcopenia is primarily due to the shrinking (atrophy) of individual muscle cells (muscle fibers) rather than a decrease in the total number of muscle cells. Therefore, the correct answer is that muscle cells get smaller in size.
This loss of muscle mass and function typically begins around the age of 30 and accelerates after the age of 60. One of the key factors contributing to this process is the reduction in physical activity. When muscles are not regularly engaged through resistance training or weight-bearing exercises, the body does not maintain their size and strength. Consequently, muscle fibers, particularly the fast-twitch fibers responsible for strength and power, begin to atrophy (shrink in diameter).
Another contributing factor is a decrease in anabolic hormones, such as growth hormone and testosterone, which play a vital role in maintaining muscle protein synthesis. As these hormone levels decline with age, the body becomes less efficient at repairing and building muscle tissue.
Moreover, neurological changes can also contribute. As the nervous system ages, there is a reduction in the number of motor neurons that stimulate muscle fibers. When motor neurons are lost, the muscle fibers they control become inactive and eventually atrophy.
Importantly, the other options are incorrect:
- a. get larger in size: This is the opposite of what occurs during aging.
- b. attach to the nervous system: Muscle cells are already connected to the nervous system; aging may reduce this connectivity, not increase it.
- c. increase in number: Muscle cells do not significantly increase in number; muscle growth occurs mainly through hypertrophy (increased size), not hyperplasia (increased number).
In summary, older adults lose muscular strength largely because their muscle cells get smaller in size, leading to decreased muscle mass and diminished physical function.