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A classic example of a syncytium is the formation of skeletal muscle.Large skeletal muscle fibers form by the fusion of thousands of individual muscle cells. The multinucleated arrangement is important in pathologic states such as myopathy, where focal necrosis (death) of a portion of a skeletal muscle fiber does not result in necrosis of the adjacent sections of that same skeletal muscle ...
Muscle fibers can only contract up to 40% of their fully stretched length. [citation needed] Thus the short fibers of pennate muscles are more suitable where power rather than range of contraction is required. This limitation in the range of contraction affects all muscles, and those that act over several joints may be unable to shorten ...
Structure of a skeletal muscle. A key component in lateral force transmission in skeletal muscle is the extracellular matrix (ECM). Skeletal muscle is a complex biological material that is composed of muscle fibers and an ECM consisting of the epimysium, perimysium, and endomysium. It can be described as a collagen fiber-reinforced composite.
The endomysium, meaning within the muscle, is a wispy layer of areolar connective tissue that ensheaths each individual muscle fiber, or muscle cell. [1] [2] [3] It also contains capillaries and nerves. It overlies the muscle fiber's cell membrane: the sarcolemma. Endomysium is the deepest and smallest component of muscle connective tissue.
Broadly there are two types of muscle fiber performing in muscle contraction, either as slow twitch or fast twitch . A single muscle such as the biceps brachii in a young adult human male contains around 253,000 muscle fibers. [11] Skeletal muscle fibers are the only muscle cells that are multinucleated with the nuclei usually referred to as ...
Signal transmission from nerve to muscle at the motor end plate. The neuromuscular junction is the synapse that is formed between an alpha motor neuron (α-MN) and the skeletal muscle fiber. In order for a muscle to contract, an action potential is first propagated down a nerve until it reaches the axon terminal of the motor neuron.
The pennation angle is the angle between the longitudinal axis of the entire muscle and its fibers. The longitudinal axis is the force generating axis of the muscle and pennate fibers lie at an oblique angle. As tension increases in the muscle fibers, the pennation angle also increases.
Sarcoplasm is the cytoplasm of a muscle cell. It is comparable to the cytoplasm of other cells, but it contains unusually large amounts of glycogen (a polymer of glucose), myoglobin, a red-colored protein necessary for binding oxygen molecules that diffuse into muscle fibers, and mitochondria.