Muscular Cell Quiz

<p>Type 1</p> Signup and view all the answers

<p>Muscles of the back</p> Signup and view all the answers

<p>Type 2B</p> Signup and view all the answers

<p>Type 2A</p> Signup and view all the answers

<p>It is a large complex with two identical heavy chains and two pairs of light chains</p> Signup and view all the answers

<p>To conduct the impulse from outer to deeper parts of the muscle</p> Signup and view all the answers

<p>The H zone disappears as it contains both actin and myosin</p> Signup and view all the answers

<p>Sarcolemma</p> Signup and view all the answers

<p>To release calcium ions for muscle contraction</p> Signup and view all the answers

<p>Smooth</p> Signup and view all the answers

<p>Type 1 (Red) muscle fibers</p> Signup and view all the answers

<p>Red (slow; type 1) muscle fibers</p> Signup and view all the answers

<p>It is a protein that forms thick filaments in muscle fibers</p> Signup and view all the answers

<p>They transport action potentials deep into the muscle fiber</p> Signup and view all the answers

<p>Trobomodulin</p> Signup and view all the answers

<p>Myosin heavy chains are thin, rodlike motor proteins twisted together as myosin tails.</p> Signup and view all the answers

<p>To regulate the calcium concentration within the myofibril.</p> Signup and view all the answers

<ol> <li>Muscle cell = muscle fiber = myofiber.</li> </ol> Signup and view all the answers

<ol> <li>Skeletal (striated and voluntary), 2) Cardiac (striated and involuntary), 3) Smooth (non-striated and involuntary).</li> </ol> Signup and view all the answers

<p>Myofibrils are the contractile elements of skeletal muscle cells. They are composed of overlapping thick (myosin) and thin (actin) myofilaments.</p> Signup and view all the answers

<p>Sarcomere is the functional contractile unit of striated muscles. It consists of one dark band (A band) in the middle and two halves of light band (I band) on either side.</p> Signup and view all the answers

<p>The thin filament (actin) is formed of F-actin, which is a double helical polymer of G-actin protein. It also includes tropomyosin and troponin.</p> Signup and view all the answers

<p>The thick filament (myosin) is 15nm in diameter and consists of 300 myosin molecules. Each myosin molecule resembles two golf clubs and has two identical heavy chains and two pairs of light chains.</p> Signup and view all the answers

<p>The three types of muscle fibers are: 1) Red (slow; type 1) - slow but repetitive, not easily fatigued, high in oxidative enzymes, and low in ATPase; 2) Intermediate (type 2A) - fast but not easily fatigued, intermediate in oxidative enzymes and ATPase; 3) White (fast; type 2B) - fast and easily fatigued, low in oxidative enzymes, high in ATPase and phosphorylases.</p> Signup and view all the answers

<p>Myotonia is a neuromuscular condition characterized by slow or delayed relaxation of a muscle after voluntary contraction. It is caused by mutations in the gene that controls voltage-gated chloride ion (Cl-) in the sarcolemma of skeletal muscle fibers.</p> Signup and view all the answers

<p>Delayed onset muscle soreness (DOMS) is the sensation of skeletal muscle soreness, stiffness, and pain that occurs after a single, unaccustomed, intensive exercise event. The underlying mechanisms include loss of muscle fiber integrity (sarcolemmal tearing, myofilament disruption, cytoskeletal disarray, Z-band streaming) accompanied by acute inflammation in the endomysium, which sensitizes surrounding nociceptors (pain receptors).</p> Signup and view all the answers

<p>The sarcoplasmic reticulum is responsible for storing and releasing calcium ions during muscle contraction. When a muscle is stimulated to contract, calcium ions are released from the sarcoplasmic reticulum, which triggers the interactions between actin and myosin filaments, leading to muscle contraction.</p> Signup and view all the answers