BIOLOGY 2A03 Lecture Notes - Lecture 10: Patellar Ligament, Quadriceps Femoris Muscle, Muscle Spindle
13 Mar 2018
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Document Summary
Fish swimming muscles - anatomical separation between oxidative (red) and glycolytic (white) fibres. Glycolytic fibres recruited at higher swimming speed - when greater force production is required otherwise on red oxidative muscle is recruited. The muscle spindle senses stretch, triggers action potentials in afferent neurons. Contraction of the quadriceps muscle and relaxation of the hamstrings shortens the quadriceps muscle. Muscle spindle = small number of modified muscle fibres (intrafusal fibres) - innervated by sensory neurons. As muscle stretched - muscle lengthens, intrafusal fibres stretched, stimulate ap frequency in sensory neurons in proportion to degree of stretch. Golgi tendon orgon (gto) = capsules of connective tissue intertwined with collagen fibres in tendons. When muscle stretches tendons, gtos = activated, increasing ap frequency in proportion to tension in tendon (and thus, the muscle) Gto - sensors, stretch sensitive, afferent activity dictated by amount of stretch (stretching increases ap frequency)
