Muskels

Muskels is not a standard English term. In German, Muskels may appear as the genitive form of Muskel in phrases such as des Muskels, meaning “of the muscle.” In other languages and in English contexts, the term is generally a misspelling of “muscles” or an occasional loanword. This article treats Muskels as a reference to the muscular system in humans and other animals, focusing on the biology of muscles rather than spelling specifics.

Muscles are contractile tissues that convert chemical energy into force. In vertebrates they are organized into three main types: skeletal muscles, which move bones and are under voluntary control; smooth muscles, which govern the walls of hollow organs and blood vessels; and cardiac muscle, which powers the heart. A muscle is composed of muscle fibers bundled into fascicles, wrapped by connective tissue, and supplied by nerves and blood vessels.

Within muscle fibers, myofibrils contain sarcomeres, the basic contractile units made of actin and myosin filaments. When a nerve impulse triggers the release of calcium, cross-bridges form between actin and myosin, shortening the sarcomere and producing contraction. Muscle contraction uses ATP; mitochondria provide energy; blood supplies oxygen and nutrients.

Muscle strength and size adapt to use: resistance training increases cross-sectional area and strength; endurance training enhances metabolic capacity. Adequate protein, rest, and recovery support growth. Common issues include strains, cramps, and atrophy from inactivity or illness.

See also: Muscle anatomy, Sarcomere, Neuromuscular system.