What physiological change occurs in response to increased workload on skeletal muscle?

The correct response is physiological hypertrophy, which refers to the process where skeletal muscle fibers increase in size as a direct adaptation to increased workload or stress. This phenomenon is triggered by factors such as resistance training and other forms of physical exertion.

During physiological hypertrophy, the muscle cells respond to the overload by synthesizing more myofibrillar protein and increasing their cross-sectional area, which enhances muscle strength and performance. This adaptation is a healthy response that often leads to improvements in physical function and fitness.

On the other hand, pathological hypertrophy signifies an abnormal increase in muscle mass often resulting from diseases, such as hypertension or heart disease, where the muscle adapts in a negative manner without the beneficial effects seen in physiological hypertrophy. Pathological atrophy refers to a decrease in muscle size due to disuse, malnutrition, or disease, while muscle fibrosis involves the replacement of muscle tissue with fibrous connective tissue, which further impairs function and strength. Understanding these distinctions is essential in recognizing the healthy adaptations versus the detrimental changes in muscle tissue.