Muscle Cell Structure

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Muscle Cell Anatomy (striated muscle tissue) some cell structures have taken on new functions: cell membrane = sarcolemma cytoplasm = sarcoplasm ER = sarcoplasmic reticulum several nuclei (skeletal muscle) lots of mitochondria T tubules tube or tunnel-like infoldings of sarcolemma open to cell surface extend into muscle cell surround sarcoplasmic reticulum Myofibrils regularly overlapping filaments (in striated mm) various bands and zones one set = sarcomere surrounded by SR SR in turn surrounded by T-Tubules myofibrils consists of packets of: thick filaments myosin (200molecules/filament) thin filaments actin, troponin, tropomyosin Muscle Cell Contraction: 1. nerve impulse arrives at neuromuscular junction 2. ACh is released and diffuses across synapse 3. binds to receptor on sarcolemma and initiates an impulse 4. impulse travels across sarcolemma and into T tubules 5. impulse triggers release of Ca++ from SR 6. Ca++ binds to troponin which moves tropomyosin away from actin binding sites acts as a switch: without Ca++ prevents interaction between actin & myosin with Ca++ allows interaction Anatomy & Physiology – Muscule Cells; Ziser, 2004 7. Myosin binds with actin in ratchet-like mechanism pulls thin filaments toward thick filaments 8. Thick & thin filaments telescope into each other causing shortening of muscle fibers = contraction requires lots of ATP: causes cross bridges of myosin filaments to rotate to different angles and move thin filaments foreward ATP is needed for both attachment and release of each myosin head muscles shorten up to 60% (ave=35-50%) one cycle results in ~1% shortening so many cycles are involved Relaxation 1. ACh is rapidly broken down by ACh esterase stops generation of muscle action potential 2. When stimulus stops, Ca++ ions reenter SR keeps [Ca++] 10,000 lower in sarcoplasm than in SR 3. Troponin moves back in to block interaction of actin and myosin, muscle cell relaxes Botulism toxin – blocks release of Ach paralysis Tetanus toxin – interferes with inhibition of antagonists all muscles contract black widow toxin – stimulates massive release of Ach intense cramping & spasms nicotine - mimics Ach prolonges hyperactivity atropine, curare - prevents Ach from binding to receptors paralysis Anatomy & Physiology – Muscule Cells; Ziser, 2004.

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1933.Full.Pdf
0270.6474/84/0408-1933$02.00/O The Journal of Neuroscience Copyright 0 Society for Neuroscience Vol. 4, No. 8, pp. 1933-1943 Printed in U.S.A. August 1984 PARTIAL PURIFICATION AND FUNCTIONAL IDENTIFICATION OF A CALMODULIN-ACTIVATED, ADENOSINE 5’-TRIPHOSPHATE-DEPENDENT CALCIUM PUMP FROM SYNAPTIC PLASMA MEMBRANES1 DIANE M. PAPAZIAN,* HANNAH RAHAMIMOFF,$ AND STANLEY M. GOLDIN§’ Departments of *Biological Chemistry and $Pharmacology, Harvard Medical School, Boston, Massachusetts 02115 and *Department of Biochemistry, Hadassah Medical School, Hebrew University, Jerusalem, Israel Received July 18, 1983; Revised February 27, 1984; Accepted February 28, 1984 Abstract Synaptic plasma membranes isolated from rat brain contain a calmodulin-activated Ca2+ pump. It has been purified 80- to 160-fold by solubilization with Triton X-100 and affinity chromatography on a calmodulin- Sepharose 4B column. After reconstitution into phospholipid vesicles, the affinity-purified pump efficiently catalyzed ATP dependent Ca2+ transport, which was activated 7- to g-fold by calmodulin. The major protein component of the affinity-purified preparation had a M, = 140,000; it was virtually the only band visualized on a Coomassie blue-stained SDS polyacrylamide gel. It has been identified as the Ca”’ pump by two functional criteria. First, it was phosphorylated by [y-““P]ATP in a Ca’+-dependent manner; the phosphorylated protein had the chemical reactivity of an acyl phosphate, characteristic of the phosphorylated intermediates of ion-transporting ATPases. Second, the protein was enriched by transport-specific fractiona- tion, a density gradient procedure which uses the transport properties of the reconstituted Ca2+ pump as a physical tool for its purification.
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Te2, Part Iii
TERMINOLOGIA EMBRYOLOGICA Second Edition International Embryological Terminology FIPAT The Federative International Programme for Anatomical Terminology A programme of the International Federation of Associations of Anatomists (IFAA) TE2, PART III Contents Caput V: Organogenesis Chapter 5: Organogenesis (continued) Systema respiratorium Respiratory system Systema urinarium Urinary system Systemata genitalia Genital systems Coeloma Coelom Glandulae endocrinae Endocrine glands Systema cardiovasculare Cardiovascular system Systema lymphoideum Lymphoid system Bibliographic Reference Citation: FIPAT. Terminologia Embryologica. 2nd ed. FIPAT.library.dal.ca. Federative International Programme for Anatomical Terminology, February 2017 Published pending approval by the General Assembly at the next Congress of IFAA (2019) Creative Commons License: The publication of Terminologia Embryologica is under a Creative Commons Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0) license The individual terms in this terminology are within the public domain. Statements about terms being part of this international standard terminology should use the above bibliographic reference to cite this terminology. The unaltered PDF files of this terminology may be freely copied and distributed by users. IFAA member societies are authorized to publish translations of this terminology. Authors of other works that might be considered derivative should write to the Chair of FIPAT for permission to publish a derivative work. Caput V: ORGANOGENESIS Chapter 5: ORGANOGENESIS
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VIEW Open Access Muscle Spindle Function in Healthy and Diseased Muscle Stephan Kröger* and Bridgette Watkins
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Effects of Altering Titin Expression on Myofibril Assembly in a Skeletal Muscle Cell Line Qunfeng Dong Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 2000 Effects of altering titin expression on myofibril assembly in a skeletal muscle cell line Qunfeng Dong Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Cell Biology Commons Recommended Citation Dong, Qunfeng, "Effects of altering titin expression on myofibril assembly in a skeletal muscle cell line " (2000). Retrospective Theses and Dissertations. 12680. https://lib.dr.iastate.edu/rtd/12680 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this rBproduction is dependent upon the quality of the copy submitted. Broicen or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did rrat send UMI a complete manuscript and there are missing pages, these will t>e noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overiaps.
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