Structure of Skeletal Muscle - Bellarmine University

Structure of Skeletal Muscle - Bellarmine University

Structure of Skeletal Muscle Presentation by: Angela Holloman Introduction All activities that involve movement depend on muscles 650 muscles in the human body

Various purposes for muscles for: Locomotion Upright posture Balancing on two legs

Support of internal organs Controlling valves and body openings Production of heat Movement of materials along internal tubes Three types of muscles in the human body Skeletal Cardiac Smooth

Skeletal Muscle Skeletal muscles are muscles which are attached to the skeleton. 40% of human body mass Skeletal muscles are mainly responsible for locomotion, and voluntary contraction and relaxation. Structure of Skeletal muscles Skeletal muscles are composed of clusters of muscle cells. Muscle fibers

Myofibers Myocytes A muscle consists of packages of muscle cells called fascicles A muscle cell is long and spindle shaped Structure of Skeletal muscles Cell structure

Muscles cells contain many nuclei The plasma membrane sarcolemma The cytoplasm sarcoplasm Length Diameter

ranges from 0.1cm to more the 30cm in length ranges from 0.001cm to 0.01cm in diameter Myofibrils elongated protein molecules aligned in parallel arrangements extend the full length of the cell. Structure of Skeletal muscles

The myofibril consists of protein chains called myofilaments Myofilaments have a symmetrical, alternating pattern of thick and thin elements. Skeletal Muscle Myosin Thick myofilament

consists of a large number of bundled myosin molecules aligned in overlapping arrays. hexameric proteins with two identical heavy chains and two pairs of different light chains. regulatory light chain (RLC) essential light chain (ELC) Skeletal Muscle Actin

The thin myofilament (F-actin, filamentous actin) made up of two helically intertwined chains of G-actin (globular actin) units. Other proteins that bind to the actin molecules: Tropomyosin

The Troponin complex made up of three members Contraction of Skeletal Muscle The thick and thin filaments, along with their associated myofibril proteins, are responsible for muscle contraction. How does muscle contraction work?

Influx of calcium ions in the cell as a result of nerve impulses troponin complex pulls tropomyosin molecules away from the G-actin subunits Exposure of the myosin binding sites. The heads of the myosin molecules can bind to the actin subunits,

forming cross bridges. active site in each myosin head disrupts the high-energy bond of ATP molecules release of energy moves the myosin head towards the F- actin, when contact is made with the actin subunits, the F-actin is pulled along, causing the myofilament to contract. The coordinated contraction of all the myofilaments of all the muscle cells of a muscle, causes the entire muscle to contract. Relaxation of Skeletal Muscle

Calcium ions are carried away from the myofilaments Myosin- actin linkages loosen The troponin complex and tropomyosin bind to the myosin binding sites on the F-actin subunits, Myosin and F- actin myofilaments return to

their original positions References: Pasternak, Jack J. Human Molecular Genetics: Mechanisms of Inherited Diseases. Hoboken, New Jersey: John Wilkey & Sons Inc., 2005. March, 20, 2006

Recently Viewed Presentations

  • Chapter 1 Introduction, Historic Development, and Legal Roles ...

    Chapter 1 Introduction, Historic Development, and Legal Roles ...

    What is meant by the terms forensic science and criminalistics. What is the difference between a basic and an applied science. What is the relationship between the law, basic science and applied science. How has forensic science developed throughout history...
  • Some Information About HF Propagation -

    Some Information About HF Propagation -

    Collision frequency of electrons must be close to wavelength frequency for absorption to occur. In D region, 160 meter, 80 meter, and 40 meter waves are absorbed when the region is ionized - above 15 meters the waves pass through...
  • Analysis of Theme

    Analysis of Theme

    Assignment: Readyour chosen poem a second or third time, annotating with multiple readings (more than just * ! ? now).. When annotating, look for parts, phrases, words, or sentences that reveal something they think is important. Remember: you can these...
  • Modelling and Visualisation in Visual Studio 2010 Stuart

    Modelling and Visualisation in Visual Studio 2010 Stuart

    …understand the following about the Visualization and Architecture tools in Visual Studio 2010
  • God on the mountain - Southeastern Louisiana University

    God on the mountain - Southeastern Louisiana University

    God on the Mountain. All passengers of Uruguayan Air Force Flight 571 were Catholic, and religion was ever-present during their 72-day ordeal. A common claim of the survivors was that the God they encountered on the mountain was not the...
  • This is a good background color and a good text color

    This is a good background color and a good text color

    Invented by Rivest, Shamir, Adleman (1978) Public e and private d keys are long #s n = 256-2048+ bits Satisfy xde mod M = x for all x Finding d from e is as hard as factoring M Encryption: B...
  • ABP Staff Plan Updating -

    ABP Staff Plan Updating -

    Thursday Summary of Working Group I Initial questions I: LHC LUMI 2005; 3.9.2005; Arcidosso Oliver Brüning *
  • Virginia Opioid Addiction ECHO* Clinic

    Virginia Opioid Addiction ECHO* Clinic

    Monthly 2 hours tele-ECHO Clinics. Every tele-ECHO clinic includes 2 case presentations and a didactic presentation. Didactic presentations are developed and delivered by inter-professional experts in Sickle Cell Disease care and management