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

Info iconThis 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.
Background image of page 1

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

View Full DocumentRight Arrow Icon
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. Question 12
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

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

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