According to PearsonHigherEd.com, the sarcomere is the basic unit of contraction within a bundle of muscle fibers. Individual sarcomeres contain clearly defined bands of filaments which have a special terminology.Know More
Each sarcomere is surrounded by Z lines which denote the boundary from one sarcomere to the next. I bands are that portion of the sarcomere which contain thin filaments. H bands contain thick filaments, and A bands contain a mix of thick and thin. BiologyGuide.net states that these differences in thickness produce the characteristic striations of skeletal muscle.
BiologyGuide.net also states that the differences in thickness represent differences in what the filaments are made of. I bands contain filaments made up of actin alone, while H bands contain myosin filaments alone; A bands contain lengths of myosin.
The University of Washington describes how the filaments are typically arranged within a sarcomere; thin filaments extend from the Z lines to the center of the sarcomere, with thick filaments in the middle. The thick filaments never get as far as the Z lines, but they overlap the thin filaments that do. The two kinds of filament slide in respect to one another, causing the Z lines to be pulled toward one another, creating a muscle contraction.Learn more about Muscles
The contractile proteins in muscles are myofibrils. Myofibrils are bundles of both thick and thin fibers that have a cylindrical appearance.Full Answer >
As explained by Amy Balsinger of Davidson University, sarcomeres are the basic contractile unit of muscles. Each muscle fiber contains hundreds of sarcomeres, which are repeating subunits of myofibril proteins. Muscles contract by sliding the thin actin filaments and thick myosin filaments along each other.Full Answer >
The biceps are classified as skeletal muscles because they attach directly to the skeleton. According to Healthy Living, they are attached to the skeleton by tendons and are controlled voluntarily. As explained by education.com, skeletal muscles generally work in pairs; one muscle works in combination with an antagonistic muscle to move a joint such as the elbow or knee.Full Answer >
The function of the skeletal muscles is to move the bodies bones in order to maintain position and create movement. The skeletal muscles need the bones of the body to pull against to so that the muscles contract or relax as needed to perform the function the body is performing at the time.Full Answer >