arch Skeletal muscle contraction begins at the 11 junction

Last updated: 12/14/2022

arch Skeletal muscle contraction begins at the 11 junction in the 6 motor division of the nervous system with a 18 motor neuron releasing 2 from its synaptic terminal ACh diffuses across the synaptic cleft and binds to 33 receptors at the 17 of a skeletal muscle fiber resulting in depolarization to threshold and generation of an action potential on the 15 Once generated the action potential is propagated along the sarcolemma and down 14 causing voltage gated 13 channels on the 20 to open the rapid efflux of calcium ions into the sarcoplasm initiates the 22 cycle In the first step calcium ions bind to 28 causing 12 to shift off of the 25 on 19 In the second step the 34 head binds to the active site forming a 35 In the third step the myosin head 32 pulling actin toward the 38 of the 24 this tension producing step is also called the 8 The final step involves the binding of 10 to the myosin head promoting 30 from actin subsequent hydrolysis of ATP by 29 resets the mysoin head to it s starting position thus preparing it for the next crossbridge formation and powerstroke As long as sarcoplasmic calcium concentration remains high the active sites on actin will remain uncovered and crossbridges will continue to form maintaining tension within the muscle 41 occurs when the lower motor neuron stops releasing ACh or when calcium is actively resequesterd into the sarcoplasmic reticulum and the active sites are again covered by tropomyosin Because the myofilaments slide past one during the contraction cycle we refer to this as the 9 theory of muscle contraction ACROSS 5 explosive fibers fast myosin ATPase isoform an abundance of glycogen and few mitochondria 7 muscle contraction performed at a constant angular velocity 16 permits functioning across a wide range of resting lengths exhibited by smooth muscle 21 respiration supports low to moderate intensity work with adequate oxygen consumption 27 describes the relationship between resting sarcomere length and tension generation 31 a single stimulus contraction relaxation cycle 37 calcium release in cardiac muscle is referred to as calcium calcium release i 39 consists of intracellular ATP stores and creatine phosphate immediate energy system 40 sustained force development in response to rapid and repeated stimulation Name 21 O E 20 CD Page view 20 29 30 32 24 DOWN 1 muscle contraction during which there is no change in the length of the muscle A Read aloud Add text 27 3 recruitment of these which vary in size permit graded skeletal muscle contractions 4 lengthening phase of an isotonic contraction 23 possess a slow myosin ATPase isoform many mitochondria and significant myoglobin 26 glycolysis results in the production of lactic acid intermediate energy system 36 the phase of an isotonic contraction during which resistance is overcome and the muscle shortens Muscle Physiology 10 18 31 33 Ti 19 28 Draw Highlight 39 F Sunny A C Erase Erase 24 Renna Biology 109