Muscle Fiber Anatomy

When signaled by a motor neuron a skeletal muscle fiber contracts as the thin filaments are pulled and then slide past the thick filaments within the fibers sarcomeres. This process is known as the sliding filament model of muscle contraction figure 1010.

Chapter 9 2 Skeletal Muscle Anatomy Bio201

And then when thats done each muscle fiber myofiber or each muscle cell will not have that much contracting power.

Muscle fiber anatomy. Its able to attach to all of the troponin or at least a lot of the troponin on top of these actin filaments and then the whole muscle contracts. Fo fibers use aerobic metabolism to produce atp but produce higher tension contractions than so fibers. The primary metabolic pathway used by a muscle fiber determines whether the fiber is classified as oxidative or glycolytic.

If a fiber primarily produces atp through aerobic pathways it is oxidative. So fibers use aerobic metabolism to produce low power contractions over long periods and are slow to fatigue. The calcium floods all of these myofibrils.

More atp can be produced during each metabolic cycle making the fiber more resistant to fatigue. The strength of a muscle contration is determinded not only by the frequency of stimulation but also by the number and size of motor units recruited the number of motor units that are recruited is determined by the number of motor neurons that are stimulated by the central nervous system. The three types of muscle fiber are slow oxidative so fast oxidative fo and fast glycolytic fg.

Muscle physiology skeletal muscle fiber location and composition a review of skeletal muscle fiber cell location and anatomy using interactive animations and diagrams.

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