Wayne'sTest3 - Test #3 Human Phys. Question 1 Your answer...

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

View Full Document Right Arrow Icon
Test #3 Human Phys. Question 1 Your answer is INCORRECT. Thin filaments in skeletal muscle are composed of: a) actin b) myosin c) troponin and tropomyosin d) both [a] and [c] e) all of these answers Question 2 Your answer is CORRECT. The functional unit of skeletal muscle is the: a) smallest contractile component of a muscle fiber b) area between two Z lines c) sarcomere d) all of these answers e) none of these answers Question 3 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 4 Your answer is INCORRECT. 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 filamenst. b) bend during muscle contraction. c) bind to actin during muscle contraction. d) are not found during the I band. e) bind with troponin and tropomyosin during muscle contraction to pull them away from the actin helical chain. 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. In twitch summation: 1
Background image of page 1

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

View Full DocumentRight Arrow Icon
a) The muscle fiber is stimulated again before the action potential has returned to resting potential. b) The muscle fiber is stimulated again before the filaments have completely returned to their resting position. c) Stronger muscle contractions occur but stronger action potentials do not occur. d) Both [b] and [c] above e) All of these answers Question 7 Your answer is CORRECT. When a muscle fiber contracts, the A bands diminish in size, the H zones remain constant length, and the I bands move closer together but do not diminish in length. 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. The T tubule is responsible for storing Ca2+ for muscle contractions. a) True b) False Question 10 Your answer is CORRECT. Although there are no sarcomeres, smooth muscles still possess thick and thin filaments. a) True b) False Question 11 Your answer is CORRECT. The right half of the heart pumps blood through the _____ circuit and the left half pumps blood through the _____ circuit. a) systolic, diastolic b) coronary, pulmonary c) systemic, pulmonary d) pulmonary, systemic e) systemic, coronary Question 12 Your answer is CORRECT. The plateau of the cardiac action potential results from the opening of voltage-gated slow
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/05/2012 for the course CHEM 3321 taught by Professor Bean during the Spring '11 term at American Jewish University.

Page1 / 9

Wayne'sTest3 - Test #3 Human Phys. Question 1 Your answer...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online