TEST 3 B - Question 1 Your answer is CORRECT Thick...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Question 1 Your answer is CORRECT. Thick filaments in skeletal muscle are composed of: a) actin b) troponin and tropomyosin c) myosin d) actin, troponin, and tropomyosin e) all of these answers Question 2 Your answer is CORRECT. In an isotonic contraction, the muscle: a) changes in length and moves the load b) does not change in length but increases tension c) never converts pyruvate to lactic acid d) rapidly resynthesizes creatine phosphate and ATP Question 3 Your answer is CORRECT. Which of the following statements concerning crossbridges is incorrect? Crossbridges: a) are formed by the globular heads of the myosin molecules as they protrude from the thick filaments. b) bend during muscle contraction. c) bind to actin during muscle contraction. d) bind with troponin and tropomyosin during muscle contraction to pull them away from the actin helical chain. e) None of these Question 4 Your answer is INCORRECT. Summation: a) Results from increases in cytosolic calcium levels. b) Pumping of calcium into the sarcoplasmic reticulum. c) Can be enhanced by allowing a cell to completely relax. d) Rarely results in tetanus. e) All of these answers. Question 5 Your answer is CORRECT. Which is not characteristic of smooth muscle? a) it is under involuntary control b) it lacks troponin c) its contraction is initiated neurogenically d) it is found in the walls of hollow tube-like organs e) it is innervated by the ANS Question 6 Your answer is INCORRECT. Which of the following statements regarding skeletal muscle is not true: a) ATP in muscles cells is required for cross-bridges between actin and myosin.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
b) Calcium binds troponin allowing the myosin-binding site on actin to be made available. c) Calcium is stored in the sarcoplasmic reticulum. d) Skeletal muscles lack mitochondria e) None of these Question 7 Your answer is CORRECT. The T tubule is responsible for storing Ca2+ for muscle contractions. a) True b) False Question 8 Your answer is CORRECT. Calcium ions bind troponin allowing the myosin-binding site on actin to be made available in smooth muscle contraction. a) True b) False Question 9 Your answer is CORRECT. Blood returning from the systemic circulation: a) enters the right atrium. b) enters the left atrium c) is poorly oxygenated. d) both [a] and [c] above e) both [b] and [c] above Question 10 Your answer is CORRECT. The plateau of the cardiac contractile cells action potential results from the opening of voltage-gated slow _____ channels in the plasma membrane of the cardiac cell. a) sodium b) potassium c) calcium d) chloride e) magnesium Question 11 Your answer is CORRECT. Which of the following ECG waves represents ventricular depolarization? a) P wave b) QRS complex c) T wave d) PR segment e) ventricular depolarization occurs simultaneously with atrial repolarization and can not be recorded.
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern