What Are Sarcomeres
A sarcomere is a unit of striated muscle in the human body. Sarcomeres are the basic building blocks for most of the muscles in the body. Some of the muscles of the body is made up of bundles of muscle fibers and these are comprised of smaller strands called microfibrils. Each microfibril is in turn made up of two kinds of filaments, a thick and a thin strand organized in regular, repeating sub units, these sub units are known individually as a sarcomere. The majority of the muscles in the body are of the striated variety making them sarcomeres, this is why when people have degenerative muscle diseases like Parkinson's or types of muscular dystrophy, the result is an overall destruction of the muscles to the point of paralysis.
The sarcomeres capacity for contraction is what makes it important to skeletal muscle features, the thick and thin filaments are what do the work of the a muscle. The protein myosin arranged in a cylindrical shape on the molecular level is what makes up a thick filament. Actin is the protein arranged in the same fashion that make up thin filaments that look like two strands of pearls twisted around each other.