MICROANATOMY

Detailed explanation-1: -Answer and Explanation: A long, filamentous organelle found within muscle cells that has a banded appearance is a myofibril. These form muscle fibers and occur parallel to each other. Myofibrils are comprised of sarcomeres.

Detailed explanation-2: -Skeletal muscle looks striped or “striated” – the fibres contain alternating light and dark bands (striations) like horizontal stripes on a rugby shirt. In skeletal muscle, the fibres are packed into regular parallel bundles.

Detailed explanation-3: -A striated muscle fiber contains myofibrils consisting of long protein chains of myofilaments. There are three types of myofilaments: thin, thick, and elastic that work together to produce a muscle contraction.

Detailed explanation-4: -The myocytes run parallel to each other on the long axis of the cell. The myofibrils are made up of thick and thin myofilaments, which give the muscle its striped appearance.

Detailed explanation-5: -Myofibrils run the entire length of the muscle fiber, and because they are only approximately 1.2 µm in diameter, hundreds to thousands can be found inside one muscle fiber. They attach to the sarcolemma at their ends, so that as myofibrils shorten, the entire muscle cell contracts (Figure 2).