Amphibian Muscle Contraction Results: For this experiment‚ Isometric contractions of the gastrocnemius muscle of a frog were analyzed and from this data the latent period‚ twitch‚ motor unit summation‚ tetanus‚ fatigue & mechanical summation were measured. The data was used to quantify the effect of passive tension on the twitch force‚ effect of stimulus intensity on the twitch force‚ effect of stimulus frequency on contractile force of xenopus gastrocnemius muscle. The threshold voltage obtained
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Skeletal Muscle Lab Introduction: Motor neurons and muscle fibers are the building blocks of motor units and where they intersect is called the neuromuscular junciton. The region where the flattened end of a motor neuron transmits neural impulses to a muscle is the motor end-plate. The end plate potentials depolarizes skeletal muscle fibers caused by neurotransmitters binding to the postsynaptic membrane in the neuromuscular junction. The process of contraction of the muscle cell is called excitation-contraction
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The muscle physiology of skeletal muscle was observed by using electrical‚ physical‚ and neural stimulations of an isolated gastrocnemius muscle from Rana pipiens. The gastrocnemius receives signals from the action potentials of the sciatic nerve. The muscle contraction is caused by the binding of a neurotransmitter once the action potential reaches the neuromuscular junction. Stimulation of the muscle and the sciatic nerve allows for recording and measuring of these properties. We observed twitch
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Microscopic Anatomy and Organization of Skeletal Muscle Skeletal Muscle Cells and Their Packaging into Muscles 1. Use the items in the key to correctly identify the structures described below. g; perimysium c; fascicle Key: a. b. c. endomysium epimysium fascicle fiber myofibril myofilament perimysium sarcolemma sarcomere sarcoplasm tendon 1. 2. 3. 4. 5. 6. 7. connective tissue ensheathing a bundle of muscle cells bundle of muscle cells contractile unit of muscle i; sarcomere d; fiber a; endomysium
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1. Discuss the relationship between distribution of muscle fiber type and performance. How might exercise training modify or change a person’s fiber-type distribution? Skeletal muscles contain multiple fiber types that are distinguished by their different myosin ATPase speed‚ and the development of their SR. The two main fiber types are type I and type II fibers. Type II fibers have a faster ATPase and a more developed SR than type I fibers. Type II fibers are also part of a larger motor unit‚
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S E 2 Skeletal Muscle Physiology O B J E C T I V E S 1. To define these terms used in describing muscle physiology: multiple motor unit summation‚ maximal stimulus‚ treppe‚ wave summation‚ and tetanus. 2. To identify two ways that the mode of stimulation can affect muscle force production. 3. To plot a graph relating stimulus strength and twitch force to illustrate graded muscle response. 4. To explain how slow‚ smooth‚ sustained contraction is possible in a skeletal muscle. 5. To graphically
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Lab 3 – Skeletal Muscle Physiology Introduction Skeletal muscles are composed of hundreds to thousands of individual cells‚ each doing their share of work in the production of force. As their name suggests‚ skeletal muscles move the skeleton. Skeletal muscles are remarkable machines; while allowing us the manual dexterity to create magnificent works of art‚ they are also capable of generating the brute force needed to lift a 100-lb. sack of concrete. When a skeletal muscle from an experimental
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Exercise 8 Simple Muscle Contraction • 3 Phases AB - lag phase or latent phase - (shortest) 0.00sec‚ usually less than 0.01sec - brief period that exists between the application of the stimulus and the start of contraction BC - contraction‚ 0.05sec - peak - shortening of the muscle occur CD - relaxation period‚ 0.05 sec - Occurs when Ca+ is transported back in the sarcoplasmic reticulum Single muscle contraction= 100vib/sec (tuning fork)= 0.10 sec 10vib (result) Neuromuscular junction - formed when
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Muscle Contraction Helpful links: Diagrams: http://themedicalbiochemistrypage.org/muscle.php http://classes.midlandstech.edu/carterp/Courses/bio210/chap09/lecture1.html Good explanations: http://science.howstuffworks.com/life/human-biology/muscle2.htm Quiz: http://www2.muw.edu/~jfortman/220practst2.html Flashcards: http://quizlet.com/17858377/physiology-ch-8-muscles-flash-cards/ http://quizlet.com/16553525/quiz-4-flash-cards/ http://quizlet
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Kuroda et al. Skeletal Muscle 2013‚ 3:5 http://www.skeletalmusclejournal.com/content/3/1/5 Skeletal Muscle Open Access RESEARCH Canonical Wnt signaling induces BMP-4 to specify slow myofibrogenesis of fetal myoblasts Kazuki Kuroda1‚4‚ Shihuan Kuang1‚2‚ Makoto M Taketo3 and Michael A Rudnicki1* Abstract Background: The Wnts are secreted proteins that play important roles in skeletal myogenesis‚ muscle fiber type diversification‚ neuromuscular junction formation and muscle stem cell function
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