Final answer:
Most skeletal muscles are composed of muscle fibers built from myofilaments of actin and myosin, organized into sarcomeres.
Step-by-step explanation:
Most skeletal muscles are composed of a combination of individual cells called muscle fibers, which in turn consist of myofilaments made up of proteins called actin and myosin.
These myofilaments are arranged in units called sarcomeres, the basic functional units of muscle tissue. The contraction of skeletal muscle involves the sliding filament model, where the myosin and actin fibers slide past each other, leading to muscle shortening and generating movement.
Skeletal muscle fibers are categorized into two main types: slow-twitch fibers, which are more suited for endurance activities, and fast-twitch fibers, which are adapted for quick, intense activities.
This composition varies among different muscles and individuals, often influencing performance in various physical activities.
Skeletal muscles rely on an integration of fibers, connective tissue, blood vessels, and nerve fibers, all encased within connective tissue layers known as mysia.
Structure of Skeletal Muscles: Apart from muscle fibers, skeletal muscles contain blood vessels that transport nutrients and oxygen, as well as connective tissue that provides support and structure.
Muscles can exert force and move body parts thanks to their arrangement in discrete muscles, such as the biceps brachii, which are attached to the skeleton by tendons.