What is the Origin of Skeletal Muscle Atrophy?

The term combines "skeletal muscle," referring to the voluntary striated muscle tissue, and "atrophy," derived from the Greek atrophia, meaning "lack of nourishment." It is a fundamental concept in physiology, pathology, and gerontology, where sarcopenia is the age-related form.

What is the Mechanism of Skeletal Muscle Atrophy?

Atrophy is tightly regulated by hormonal signaling, with catabolic hormones like cortisol promoting protein breakdown via the ubiquitin-proteasome system, while anabolic hormones such as testosterone and growth hormone are deficient in stimulating the mTOR pathway for synthesis. Chronic inflammation, often mediated by pro-inflammatory cytokines, also contributes significantly by signaling catabolism and inducing cellular stress. Reversing this requires a concerted effort to shift the hormonal and inflammatory balance back toward anabolism and protein accretion.

Skeletal Muscle Atrophy ∞ Area

Skeletal Muscle Atrophy

Meaning

Skeletal Muscle Atrophy is the clinical condition characterized by a decrease in muscle mass, muscle fiber size, and corresponding loss of muscular strength and function. This pathological process is driven by a sustained imbalance where the rate of muscle protein degradation significantly exceeds the rate of muscle protein synthesis. It is a major physiological concern in aging, chronic disease, and periods of prolonged immobility, directly impacting metabolic health and quality of life.