INSTANT DOWNLOAD WITH ANSWERS
Human Physiology From Cells To Systems 3rd Edition by Lauralee Sherwood – Test Bank
|Chapter 6 Indicate whether the statement is true or false.|
|1. A skeletal muscle undergoes hypertrophy mainly by producing many more muscle fibres.
|2. Foot proteins link the actin molecules together within a thin filament.
|3. A single muscle cell is known as a myofibril.
|4. The metabolic capability of a muscle fibre can affect the degree of tension it can develop.
|5. The strength and rate of contraction of the heart can be influenced by the autonomic nervous system.
|6. The two types of fast twitch fibres are interconvertible depending on the type of conditioning they receive.
|7. Cross bridges have actin binding sites that are normally covered by troponin and tropomyosin, except during excitation–contraction coupling.
|8. Thin and thick filaments overlap in the A band.
|9. The corticospinal system controls fine, discrete, voluntary body movements.
|10. According to the sliding filament mechanism of muscle contraction, the muscle fibres of one motor unit slide in closer together between the muscle fibres of adjacent motor units.
|11. Rigor mortis occurs when Ca2+ links actin and the myosin globular head together in a rigor complex.
|12. Fast-glycolytic muscle fibres do not require as much oxygen use as slow-oxidative fibres.
|13. In an isotonic contraction, only 25 percent of the energy consumed is realized as external work, and the remaining 75 percent is converted to heat.
|14. The actin filaments in sarcomere contain cross bridges.
|15. During the power stroke, all the cross bridges on myosin do not stroke in unison when pulling the actin filaments.
|16. Joints serve as fulcrums for muscle action.
|17. Tropomyosin covers the cross-bridge binding sites on the thick filaments when a sarcomere is not contracting.
|18. The contraction phase of a muscle cell lasts longer than the relaxation phase.
|19. Oxidative phosphorylation occurs within the mitochondria of muscle cells.
|20. Myosin has ATPase activity.
|21. Oxygen debt is the oxygen a skeletal muscle produces or pays off when it carries out glycolysis.
|22. Muscles that have a fine degree of control have small motor units.
|23. Myosin is considered to be a regulatory protein because it plays an important role in the regulation of muscle contraction.
|24. Tetanus occurs when a muscle fibre is stimulated so rapidly that it is not allowed to relax between stimulations, resulting in a smooth, sustained contraction.
|25. Skeletal muscles are capable of limited repair after injury.
|26. All muscle-lever systems work at a mechanical disadvantage.
|27. Gradation of muscle contraction can be accomplished by stimulating variable portions of each motor unit.
|28. Increasing the number of recruited motor units in a muscle increases its force or strength of contraction.
|29. Both multiunit and single-unit smooth muscles are under motor control from the autonomic nervous system.
|30. More tension is developed during twitch summation than during a single twitch because the duration of elevated cytosolic Ca2+ concentration increases during summation, thus increasing the availability of cross-bridge binding sites.
|31. The M line is formed by a flattened disc-like cytoskeletal protein that connects the thin filaments of two adjoining sarcomeres.
|32. Fast-oxidative muscle fibres have a high concentration of mitochondria.
|33. During muscle contraction, the A band becomes shorter.
|34. Single-unit smooth muscle and cardiac muscle are both self-excitable.
|35. ATP expenditure is required for both contraction and relaxation of a muscle fibre.
|36. Acetylcholinesterase removes ACh from receptors.
|37. Single-unit smooth muscle has no innervation.
|38. The skeletal muscle shortens during concentric, isotonic contraction.
|39. According to the sliding filament mechanism of muscle contraction, the thick filaments slide in closer together to shorten the sarcomere.
|40. Ligaments attach muscles to bones.
|41. The lever system at the elbow joint provides a mechanical advantage so that, when the biceps muscle contracts to flex the elbow joint and lift an object in the hand, the force developed in the biceps can be considerably less than the actual load that is moved.
|42. Summation events result from increasing amounts of cytoplasmic calcium levels.
|43. Slow-oxidative muscle fibres have high resistance to fatigue.
|44. A motor unit is a single muscle plus all the motor neurons that innervate it.
|45. The T tubule ranges transversely to the surface of the muscle cell membrane.
|46. Anaerobic exercise is endurance-type exercise.
|47. All skeletal muscles are attached to the skeleton.
|48. All smooth muscle is myogenic.
|49. In order for relaxation to occur, ACh must be removed from the muscle cell’s receptors.
|50. The larger the motor units within a muscle, the more precisely controlled the gradations of contraction.
|51. The H zone of the sarcomere consists of myosin but does not contain actin.
|52. Atrophy can develop in a muscle by either denervation or disuse.
|53. Central fatigue of a muscle results directly from the accumulation of lactic acid in the muscle.
|54. Skeletal muscle fibres are formed during embryonic development by the fusion of many smaller cells.
|55. Slow-oxidative muscle fibres would be found in high density in the leg muscles of Olympic sprinters.
|56. The functional unit of skeletal muscle is the myofibril.
|57. The work performed by a muscle is the force it develops divided by distance.
|58. A skeletal muscle produces motion by pulling the origin toward its insertion.
|59. Muscle tension does not develop in isometric contractions.
|60. The shorter a muscle fibre is before the onset of a contraction, the greater the force that can be developed upon the subsequent contraction because the thin filaments are already partially slid inward.
|61. With twitch summation, the muscle fibre is stimulated so rapidly that it does not have an opportunity to return to resting potential between stimuli.
|62. Muscle cells are the only cell types that contain intracellular contractile proteins.
|63. Muscle relaxation does not take place until all the ATP is used up.
|64. Denervated muscle fibres become progressively smaller and their content of actin and myosin decreases.
|65. The heart initiates its own action potentials without any external influence.
|Indicate the answer choice that best completes the statement or answers the question.|
|66. Which of the following areas is the origin of a muscle?
|67. Which of the following would happen if ATP supplies became very low or were not available in a muscle cell?
|68. How are sarcomeres arranged end to end?
|69. Which of the following composes thick filaments in skeletal muscle?
|70. Which of these statements correctly describes why you are able to repeatedly contract and relax your muscles of respiration, allowing you to breathe in and breathe out?
|71. Which of the following are in the I band of the sarcomere?
|72. Muscles developing tension while lengthening are performing what type of contractions?
|73. Fatigue is the failure of a muscle fibre to maintain which of the following as a result of previous contractile activity?
|74. Which of the following statements is NOT characteristic of cross bridges?
|75. Which of the following correctly describes multiunit smooth muscle?
|76. Which of these statements correctly describes the corticospinal system?
|77. What can activate the stretch receptors in the central portion of the muscle spindle?
|78. Which of these statements does NOT correctly describe steroids?
|79. What causes the striated appearance of skeletal muscle?
|80. Which of the following compounds binds with the calcium that enters the cell during smooth muscle excitation?
|81. The striated appearance of skeletal muscle is due to regular orderly arrangement of which of the following?
|82. What is the first means by which ATP is produced at the onset of contractile activity?
|83. In the body’s lever systems, what are the fulcrums represented by?
|84. The regulation of smooth muscle contraction is mediated by the phosphorylation of which filaments in response to calcium binding to proteins?
|85. Muscle fibres are some of the longest cells in the body. How long can they be?
|86. Which of these muscle types is striated and contains gap junctions?
|87. During aerobic exercise, what is the primary means by which ATP is produced for contractile activity?
|88. Which of the following is NOT a normal, age-related change that occurs in muscles of older individuals?
|89. Which of the following provides the energy for cross-bridge cycling during muscle contraction?
|90. Which of the following properties characterizes fast oxidative (type IIa) muscle fibres?
|91. Which of these statements correctly describes functional syncytium of cardiac muscles cells?
|92. Which of these statements correctly describes myosin?
|93. Which of these statements does NOT correctly describe smooth muscle?
|94. Which of these statements correctly describes intrafusal muscle fibres?
|95. Which of these statements correctly describes twitch summation?
|96. Which of these actions happens during contraction of skeletal muscle fibres?
|97. Which of these statements correctly describes the H zone?
|98. For which of these purposes are stretch reflexes important?
|99. Which of these statements correctly describes gap junctions?
|100. Which of these statements describes cross bridges?
|101. Which of the following is a characteristic feature of isometric muscle contractions?
|102. What happens when a muscle atrophies?
|103. Which of these statements does NOT correctly describe cross bridges?
|104. Which of the following actions is involved in developing tension in muscle fibres?
|105. If you wanted to pick up something heavier than your pencil, you would need to have a stronger muscle contraction. Which of these actions might accomplish this?
|106. Which of these conditions occurs as the result of a lack of acetylcholinesterase in the synaptic cleft?
|107. Which of these characteristics does NOT apply to smooth muscle?
|108. Which of these statements describes the sliding-filament mechanism of muscle contraction?
|109. Which of the following characteristics are shared by all three types of muscle tissues?
|110. Which statement is characteristic of most of the body’s lever systems?
|111. Which of these statements correctly describes muscle tension?
|112. What is the cause of enlargement of muscle due to weight lifting?
|113. Which of these statements applies to eccentric muscle contractions?
|114. Which of the following happens during a cross-bridge cycle in skeletal muscle?
|115. Which of the following events is NOT involved in the relaxation of muscle?
|116. Which of these statements correctly describes actin?
|117. What happens during coactivation?
|118. Which of these muscles have motor units with the highest innervation ratio?
|119. Which of the following is the first step in excitation–contraction coupling?
|120. Which of these statements correctly describes fast glycolytic (type IIb) fibres?
|121. Which muscle type is myogenic?
|122. Which of these statements applies to T tubules?
|123. Binding of which substance to myosin permits cross bridge of which action between actin and myosin?
|124. Which of these statements correctly describes single-unit smooth muscle?
|125. Which of these statements correctly describes the length–tension relationship?
|126. What initiates contraction of smooth muscle?
|127. Which of these actions happens during muscle contraction?
|128. Which of these factors is NOT a determinant of whole muscle tension?
|129. Which of these statements does NOT apply to cardiac muscle?
|130. What causes muscular fatigue?
|131. Which of these characteristics would NOT be exhibited in the muscle cells of a marathon runner’s legs?
|132. Which of these statements correctly describes twitch summation?
|133. Which of these structures controls the conscious initiation of muscle contraction?
|134. What is the term for the region between two Z lines?
|135. Which of these events results from disruption of a motor system that supplies inhibitory presynaptic inputs to motor neurons?
|136. Which of these statements correctly describes foot proteins?
|137. Which of these statements correctly describes a functional syncytium?
|138. Which of these statements correctly describes a motor unit?
|139. Which of these statements correctly describes actin?
|140. Which of these statements does NOT correctly describe different types of muscle fibres?
|141. Which of these statements correctly describes pacemaker activity?
|142. Which of the following events happens during excitation–contraction coupling?
|143. Which of these types of muscle cells are NOT capable of spontaneous depolarization?
|144. Which of these statements applies to T tubules?
|145. Which of these factors is characteristic of cardiac muscle tissue?
|146. Which of these components are involved with regulation of cross-bridge attachment activity?
|147. Which of these factors is involved in the gradation of muscle contraction?
|148. Which of the following directly blocks cross bridge interaction between actin and myosin in skeletal muscle?
|149. How does an action potential spread rapidly to the central portions of a muscle cell?
|150. Which of these substances is required for contraction of smooth muscle fibres?
|151. If the load on a muscle is increased, eventually a load will be reached at which the velocity of shortening becomes zero. What is the term for the muscle contraction at this point?
|152. Which of these activities is involved in the process of muscle relaxation?
|153. Which of these statements correctly describes myoglobin?
|154. Which of these methods is NOT a method of gradation of skeletal muscle contraction?
|155. Which of these statements correctly describes the length–tension relationship of skeletal muscle?
|156. Which of these statements does NOT correctly describe cross bridges?
|157. Which of these statements correctly describes smooth muscle?
|158. Which one of the following is the function of tropomyosin?
|159. Which of these statements does NOT correctly describe cross bridges?
|160. Which of these events happens when an action potential reaches the presynaptic terminal of the motor neuron?
|161. Submaximal isometric contractions are important for which of the following activities?
|162. Which of the following applies during an isotonic contraction of a muscle in the arm?
|163. Which of these statements correctly describes Z lines?
|164. Why must the oxygen debt be “paid off” following rigorous muscular activity?
|165. When does spastic paralysis occur?
|166. Which of these statements correctly describes summation?
|167. Which of these statements correctly describes myosin?
|168. Which of these factors causes muscle relaxation?
|169. Which of the following statements applies when trying to pick up a book?
|170. What is the functional unit of skeletal muscle?
|171. Which of these structures is the smallest unit of contraction within a skeletal muscle?
|172. During contraction, asynchronous cycling of cross bridges _______________.
|173. The sarcoplasmic reticulum stores which substance when a muscle is relaxed, and releases it for binding to which substance during contraction?
|174. Which of these statements correctly describes the summation of simple twitches?
|175. Which of these statements correctly describes contraction in skeletal and smooth muscle?
|176. Which of these statements correctly describes troponin?
|177. Which of the following structures does NOT directly influence motor neurons?
|Enter the appropriate word(s) to complete the statement.|
|178. Slow-oxidative fibres are type ____________________ fibres in the muscle.|
|179. Skeletal muscles are stimulated to contract by release of the neurotransmitter ____________________.|
|180. The contractile response of a muscle fibre to a single action potential is called a(n) ____________________.|
|181. Twitch summation is similar to the ____________________ summation of EPSPs.|
|182. The functional unit of skeletal muscle is a(n) ____________________.|
|183. A(n) ____________________ develops following sustained anaerobic activity of muscles.|
|184. A(n) ____________________ is a motor neuron and all the muscle fibres it recruits.|
|185. In smooth muscle, Ca2+ binds with the protein ____________________, which is structurally similar to troponin.|
|186. ____________________ occurs when acetylcholine is no longer available in adequate amounts to stimulate muscle fibres.|
|187. In a state of ____________________, a muscle cannot maintain any kind of tension.|
|188. The ____________________ is the extensor muscle found in the thigh that contracts during the patellar tendon reflex.|
|189. The ____________________ component is the noncontractile tissue part of a muscle.|
|190. If a muscle cell is excited, ____________________ is released from the sarcoplasmic reticulum.|
|191. ____________________ is the pigment that can store small amounts of oxygen in the skeletal muscle.|
|192. The _____________________ is the descending pathway that is concerned primarily with regulation of posture involving involuntary movements of the trunk and limbs.|
|193. The immediate source of additional ATP in muscle fibres is ____________________.|
|194. ____________________ refers to the series of events linking muscle excitation to muscle contraction.|
|195. During the ____________________ stroke, cross bridges of myosin pull the actin filaments in the sarcomere.|
|196. For a(n) ____________________ isotonic contraction, the contraction resists the stretching of the muscle.|
|197. The ____________________ is the descending motor pathway that mediates performance of fine, discrete voluntary movements of the hands.|
|198. The source of calcium in smooth muscle is the ____________________.|
|199. The immediate source for supplying additional ATP at the onset of exercise is ____________________.|
|200. The only energy source that can be used directly by the contractile machinery of a muscle fibre is ____________________.|
|201. ____________________ proteins are calcium-release channels in the muscle cell.|
|202. ____________________ and ____________________ are referred to as contractile proteins, whereas ____________________ and ____________________ are referred to as regulatory proteins.|
|203. ____________________ refers to paralysis of the legs resulting from lower spinal cord injury.|
|204. For every muscle, there is an optimal length at which maximum ____________________ is achieved.|
|205. ____________________ provides the most ATP molecules for use by muscle fibres contracting over a long period of time.|
|206. The ____________________ is a modified endoplasmic reticulum within muscle.|
|207. The gradation of whole-muscle tension depends on the number of ____________________ that contract.|
|208. ____________________ are the intracellular signal for contraction.|
|209. Thick filaments are made up of the protein ____________________, whereas thin filaments are composed of the three proteins ____________________, ____________________, and ____________________.|
|210. The three types of muscle tissue are ____________________, ____________________, and ____________________.|
|Match the bands, labelled a. through c., with the descriptions. (Options may be used more than once or not at all.)
|211. composed of thin filaments only|
|212. composed of thick filaments only|
|213. composed of thick and thin filaments|
|214. shortens during muscle contraction|
|215. remains the same size during muscle contraction|
|Match the muscle fibre types, labelled a. through c., with the characteristics. (Options may be used more than once or not at all.)
|216. has myosin ATPase activity|
|217. most resistant to fatigue|
|218. most readily fatigues|
|219. has numerous mitochondria|
|220. can be transformed into another fibre type by specific training|
|221. contains considerable myoglobin|
|222. found predominantly in muscles designed for endurance|
|223. has the largest diameter|
|224. has abundant glycolytic enzymes|
|225. the most powerful fibre|
|226. found predominantly in muscles adapted for short-duration, high-intensity activities|
|227. produces the most lactic acid|
|228. hypertrophies in response to weight training|
|229. uses up considerable glycogen|
|230. requires a constant supply of oxygen|
|Match the types of muscles, labelled a. and b., with the characteristics.
|231. muscle tension exceeds the load|
|232. load exceeds muscle tension|
|233. length changes|
|234. length remains constant|
|235. tension remains constant|
|236. important in maintaining posture|
|237. used to accomplish movement|
|238. does not accomplish any work|
|Match the muscle-tension receptors, labelled a. through c., with the characteristics. (Options may be used more than once or not at all.)
|239. monitors change in muscle length|
|240. detects change in muscle tension|
|241. activated by muscle stretch|
|242. initiates a monosynaptic reflex|
|243. unless compensatory measures are taken, this receptor becomes slack|
|244. involved in negative feedback|
|245. provides information to motor regions of the brain|
|Match the skeletal muscle proteins, labelled a. through f., with the descriptions. (Options may be used more than once or not at all.)
|246. found in the A band|
|247. found in the I band|
|248. contractile protein(s)|
|249. found in the H zone|
|250. regulatory protein(s)|
|251. found in thin filament|
|253. possess cross bridges|
|254. shape consists of two globular heads attached to a tail|
|255. found in thick filament|
|256. has (have) ATPase capacity|
|257. can bind with myosin during muscle contraction|
|258. lie(s) near the groove of the thin filament helix|
|259. found in the sarcomere|
|260. can bind with Ca2+ during contraction|
|261. form(s) a helical chain|
|Match the sarcomere components, labelled a. through d., with the characteristics. (Options may be used more than once or not at all.)
|262. dark band|
|263. light band|
|264. contains only thick filaments|
|265. contains only thin filaments|
|266. contains partially overlapping thick and thin filaments|
|267. joins adjacent sarcomeres together|
|268. runs down the middle of the A band|
|269. runs down the middle of the I band|
|Match the types of muscles, labelled a. through g., with the properties in question. (Options may be used more than once or not at all.)
|270. contain(s) actin, myosin, troponin, and tropomyosin|
|271. contain(s) gap junctions|
|272. innervated by motor neurons|
|274. maintain(s) a constant resting membrane potential unless stimulated|
|275. innervated by the autonomic nervous system|
|276. attached to bones|
|277. considered to be involuntary|
|278. Thick and thin filaments are highly organized into a banding pattern.|
|279. found in the heart|
|280. can exist over a variety of lengths with little change in tension|
|282. found in the walls of hollow organs such as the stomach|
|283. behave(s) as a functional syncytium|
|284. under voluntary control|
|285. has/have a clear-cut, length-tension relationship|
|286. basis of contraction is cross-bridge interaction between actin and myosin|
|287. contraction triggered as Ca2+ physically pulls troponin and tropomyosin from its blocking position over actin’s binding sites for the cross bridges|
|288. Myosin must be phosphorylated before it can bind with actin|
|289. contain(s) T tubules|
|290. display(s) pacemaker potentials and slow-wave potentials|
|291. Match the muscle type with the correct characteristics by using the answer codes a. through e.____ cardiac muscle____ multiunit smooth muscle____ single-unit smooth muscle____ skeletal musclea. voluntary, neurogenic, and striatedb. voluntary, neurogenic, and nonstriatedc. involuntary, myogenic, and striatedd. involuntary, neurogenic, and nonstriatede. involuntary, myogenic, and nonstriated|
|292. Which events involved in muscle cell contraction are sequenced in the correct order? 1. Sodium channels open, allowing sodium to flow in.2. Impulse reaches axon’s synaptic knob.3. ACh binds to receptors on sarcolemma.4. Synaptic vesicles fuse with neuron’s membrane and release ACh via exocytosis.5. If enough sodium moves into the muscle cell, an impulse (action potential) develops.
|293. Match the muscle term with the correct characteristic by using the answer codes a. through e.____ creatine phosphate____ myoglobin____ glycogen____ lactic acid____ glucosea. a storage form of glucose used in muscle cells requiring rapid energy releaseb. a molecule that can quickly, but temporarily, make ATPc. an oxygen-storing protein that makes muscle tissue appear redd. a fuel molecule for cell respiration or fermentatione. fermentation product when our cells become anaerobic|
|294. Rank the following muscle cell components from largest to smallest. 1 troponin2 myofibril3 sarcomere4 thin filament5 muscle fibre
|295. Describe how summations occur in muscle cells.|
|296. How does contraction of smooth muscle differ from that of skeletal muscle?|
|297. Compare and contrast isotonic versus isometric contractions.|
|298. What are the means by which skeletal muscle fibres utilize energy for contraction?|
|299. Describe calcium’s role in the contraction of the sarcomere in skeletal and cardiac muscle tissues.|
|183. oxygen debt|
|184. motor unit|
|186. Neuromuscular fatigue|
|188. quadriceps femoris|
|192. multineuronal (extrapyramidal) system|
|193. creatine phosphate|
|194. Excitation–contraction coupling|
|197. corticospinal (pyramidal) system|
|198. extracellular fluid|
|199. creatine phosphate|
|202. Myosin; actin; tropomyosin; troponinMyosin; actin; troponin; tropomyosinActin; myosin; troponin; tropomyosinActin; myosin; tropomyosin; troponin|
|205. Oxidative phosphorylation|
|206. sarcoplasmic reticulum|
|207. muscle fibresmotor units|
|208. Calcium ions|
|209. myosinactin; tropomyosin; troponin (in any order)|
|210. cardiac; skeletal; smooth (in any order)|
|291. c, d, e, a|
|293. b, c, a, e, d|
|295. Answers will vary.|
|296. Answers will vary.|
|297. Answers will vary.|
|298. Answers will vary.|
|299. Answers will vary.|
|Indicate whether the statement is true or false.|
|1. The right ventricle pumps out blood low in oxygen content, whereas the left ventricle pumps out blood high in oxygen content.
|2. The bundle of His and Purkinje system facilitate the rapid spread of the action potential throughout the ventricles.
|3. Stroke volume can vary by alterations in both intrinsic and extrinsic control mechanisms.
|4. The tricuspid prevents regurgitation of blood from the right ventricle back into the right atrium.
|5. Sympathetic stimulation of the heart increases calcium permeability.
|6. Atrial repolarization does not occur.
|7. The heart valves are innervated by the autonomic nervous system.
|8. The only point of electrical contact between the atria and the ventricles is the AV valve.
|9. According to the Frank–Starling law of the heart, the greater the stroke volume, the smaller the subsequent end-diastolic volume will be, because as more blood is squeezed out, the heart cannot fill as completely during the next diastole.
|10. When ECF K+ levels fall below normal, the heart becomes weak, flaccid, and dilated.
|11. Parasympathetic stimulation slows the rate of depolarization of the SA node and thus decreases the heart rate.
|12. The T wave represents the depolarization of the ventricles.
|13. Angina pectoris develops from the abundance of oxygen of blood in the coronary circulation.
|14. Atrial systole lasts throughout ventricular systole.
|15. With 2:1 rhythm, the atrial rate is very rapid and the ventricular rate is normal or above normal, whereas with 2:1 block, the atrial rate is normal but the ventricular rate is below normal
|16. The semilunar valves are positioned between the atria and ventricles.
|17. Parasympathetic stimulation of the AV node increases the speed of transmission of the impulse through the AV node.
|18. The AV valve controls the amount of blood entering the atrium from the venous system.
|19. The end-diastolic volume is the maximum amount of blood in the ventricle after ventricular filling is complete.
|20. Ventricular filling occurs more rapidly early in diastole than it does later in diastole.
|21. The plateau phase of the action potential in a contractile cardiac muscle cell occurs as a result of activation of slow Ca2+ channels.
|22. Most ventricular filling is accomplished during atrial contraction.
|23. Ventricular ejection occurs once the afterload has been overcome.
|24. The rate of appearance of the QRS and T waves is unaffected if the heart develops a complete heart block.
|25. Gap junctions are absent between atrial and ventricular cells.
|26. The stroke volume is the total volume of blood ejected by both ventricles per minute.
|27. The SA node is the pacemaker of the heart.
|28. Left-sided congestive heart failure can lead to pulmonary edema.
|29. The heart is posterior to the sternum.
|30. A pacemaker potential depends on the increased inward current of calcium ions.
|31. Diastole refers to the period of cardiac relaxation.
|32. The action potential impulse passes through the AV node between the P wave and QRS complex.
|33. One important function of the intrinsic control of the heart (Frank–Starling law of the heart) is to maintain the left and right cardiac outputs in balance.
|34. The second heart sound is due to closure of the AV valves.
|35. HDLs have less protein than LDLs.
|36. The ESV of the heart averages about 140 mL.
|37. The first heart sound signals the onset of ventricular systole.
|38. The functional syncytia of the myocardium are offered by the intercalated discs.
|39. Sympathetic stimulation increases the heart rate.
|40. The ECG is an actual recording of cardiac electrical activity.
|41. Normally, the stroke volume of the right side of the heart is the same as the stroke volume of the left side of the heart.
|42. Stroke volume is determined by the extent of venous return and parasympathetic activity.
|43. The function of the chordae tendineae and papillary muscles is to hold the AV valves wide open during diastole to ensure complete ventricular filling.
|44. Not all forms of LDL are equally harmful to the heart.
|45. The cardiac output is the same as the cardiac reserve of the heart.
|46. The AV and semilunar valves are never open at the same time.
|47. Increased EDV results in decreased stroke volume.
|48. According to the Frank–Starling law of the heart, the shorter the initial length of the cardiac muscle fibres prior to contraction, the more forceful will be the subsequent contraction because the fibres are already partially contracted.
|49. The EDV of the heart averages about 65 mL.
|50. Cardiac muscle receives its blood supply primarily during ventricular systole when blood is being pumped out into the aorta.
|51. The ventricles always depolarize at the same rate as the SA node depolarizes.
|52. The semilunar valves close to prevent the backflow of blood into the ventricles.
|53. The long refractory period of cardiac muscle prevents tetanic contractions of the heart.
|54. Hypertension decreases the afterload and increases the preload.
|55. The action potential spreads through the atria by gap junctions, but there are no gap junctions present in the ventricles, so the impulse must be propagated throughout the ventricular myocardium by the bundle of His and Purkinje system.
|56. The aortic valve prevents backflow of blood from the aorta into the left ventricle during ventricular diastole.
|57. Most blood flow through the coronary vessels occurs during ventricular systole when the heart is driving blood forward.
|58. Cardiac tamponade refers to failure of the AV node to transmit the action potential from the atria to the ventricles.
|59. Pacemaker activity by the Purkinje fibres is an example of an ectopic focus.
|60. The amount of blood pumped out of the heart during each beat is known as the cardiac output.
|61. The heart muscle receives its oxygen and nutrients directly from the blood within its chambers during ventricular diastole.
|62. The pulmonary circulation carries oxygenated blood from the lungs to the body tissues.
|63. The extent of ventricular filling is the preload of the heart, whereas the magnitude of the arterial blood pressure is the afterload of the heart.
|64. Complete heart block results from a damaged AV node.
|65. The average resting heart rate is normally established by the rhythm of the AV node.
|66. The heart utilizes glucose almost exclusively for energy production.
|67. The refractory period in cardiac muscle is much shorter than the refractory period in skeletal muscle to ensure that the heart can quickly be restimulated to produce alternate periods of contraction and relaxation.
|68. Contraction of the spirally arranged cardiac muscle fibres produces a wringing effect for efficient pumping.
|69. The atria and the ventricles contract at the same time to ensure efficient pumping action.
|70. Cardiac output is stroke volume times the heart rate.
|71. Arteries carry blood toward the ventricles.
|72. All of the blood within the ventricles is ejected during ventricular systole.
|73. The heart undergoes tetanic contraction during sympathetic stimulation to squeeze out more blood.
|Indicate the answer choice that best completes the statement or answers the question.|
|74. Which of these statements correctly describes the AV nodal delay?
|75. Twelve complete ECG patterns are recorded from a subject over 10 seconds. If this pattern continues, what is the rate of the heartbeat in the subject?
|76. Which of these criteria must be met for the heart to function efficiently?
|77. Which of these statements correctly describes extrasystole of the heart?
|78. Which of the following is the cranial nerve of the parasympathetic nervous system that signals the heart?
|79. Which structures join adjacent cardiac muscle cells end-to-end in the ventricles?
|80. The right half of the heart pumps blood through the pulmonary circuit. Through which circuit does the left half pump blood?
|81. Which of these molecule(s) induces vasodilation of coronary arteries?
|82. Which cardiac valve prevents regurgitation of blood from the right ventricle to the atrium?
|83. Which of the following correctly describes ectopic focus?
|84. Which of the following is correct for the first heart sound?
|85. Which of the following is the function of the ventricular conduction system of the heart?
|86. Which of the following is a compensatory mechanism that comes into play in order to maintain the cardiac output for the failing heart?
|87. What component of the cardiac conduction system distributes electrical signals through the papillary muscles directly?
|88. The parasympathetic nervous system has little effect on which of these types of activity?
|89. Which of these events occurs at rapid heart rates?
|90. Which of these actions happens during heart failure?
|91. Why is the sinoatrial node the heart’s normal pacemaker?
|92. What is the membrane potential of cardiac muscle cells at rest?
|93. Which of the following occurrences causes the dicrotic notch on the aortic pressure curve?
|94. Which vessel carries blood with a comparatively high concentration of oxygen?
|95. What does the QRS complex represent?
|96. Which of these terms refers to the term systole?
|97. Which of these events happens in an insufficient AV valve?
|98. A patient has an EDV of 85 mL and an ESV of 35 mL with a heart rate of 50. What is this patient’s cardiac output?
|99. Which of these statements correctly describes cardiac fibrillation?
|100. What is a metabolic predictor of heart disease that is independent of one’s cholesterol/lipid profile?
|101. Which of the following factors will NOT increase cardiac output?
|102. According to the text, why is the wall of the left ventricle thicker than the wall of the right ventricle?
|103. Which of these functions is done by the aortic valve?
|104. Which of these events is happening during the isovolumetric phase of ventricular systole?
|105. Which heart chamber has the greatest workload?
|106. Which of these statements correctly describes action potentials in the heart?
|107. On an electrocardiogram, what represents depolarization of the ventricles?
|108. When does the aortic semilunar valve open?
|109. The electrocardiogram is most useful in determining which component of cardiac output?
|110. Which of the following situations will NOT increase stroke volume?
|111. What is the primary function of the pericardial sac?
|112. What is the normal direction of the impulse through the conduction system of the heart for each cardiac cycle?
|113. Which is the result of vagal influences on the heart?
|114. The second heart sound occurs when the semilunar valves close. What does this mark?
|115. Which of the following actions is done by the chordae tendineae?
|116. Which of the following events occurs due to sympathetic stimulation of the heart?
|117. On a normal ECG, a wave for repolarization of the atria is not recorded. Why?
|118. When does blood flow occur through the coronary circulation?
|119. Which of the following statements correctly describes the Frank–Starling law of the heart?
|120. If the EDV were held constant, what could accomplish increased stroke volume?
|121. Which of these statements correctly describes the systemic circulation?
|122. If the cardiac output is 4800 mL/min and the heart rate is 60 beats per minute, what is the average stroke volume in millilitres?
|123. Which of these statements correctly describes cardiac output?
|124. What percentage of ventricular filling is normally accomplished before atrial contraction begins?
|125. What is the function of the atrioventricular node?
|126. What happens during isovolumetric ventricular contraction?
|127. What is the term for the period lasting from closure of the AV valve to opening of the aortic valve?
|128. Which of the following normally carries out the fastest rate of autorhythmicity?
|129. Which of these statements correctly applies to the cardiac muscle?
|130. Which of the following actions is done by the semilunar valves?
|131. Which of these statements correctly describes the refractory period of cardiac muscle?
|132. Which of these statements does NOT correctly describe cardiac muscle cells?
|133. Why the heart does not require the nervous system to initiate contraction events?
|134. Which of these is the low-resistance pathway that permits electrical activity to pass from cell to cell in myocardial tissue?
|135. A condition in which the heart is contracting in an uncontrolled, rapid, and irregular manner _______________
|136. Which of the following occurs when an individual is sympathetically stimulated?
|137. What rhythm characterizes atrial flutter as impulses pass from the AV node to the ventricles?
|138. Which of these ECG waves represents ventricular repolarization?
|139. Which of the following describes blood returning from the lungs?
|140. What does a whistling murmur heard between the second and first heart sounds indicate?
|141. Why can’t tetany of the heart occur under normal conditions?
|142. Which of these sequences is the normal sequence of the spread of cardiac excitation?
|143. Which of these events happens when the heart is sympathetically stimulated?
|144. Which of the following actions produces the second heart sound?
|145. When does electrical activity occur at the AV node?
|146. If a mitral valve damaged by rheumatic fever fails to open completely, what is this called?
|147. Which of these statements correctly describes the AV node?
|148. Which of the following is the normal pacemaker of the heart?
|149. Which of these terms refers to the volume of blood ejected from each ventricle during a contraction?
|150. Which of these nerves to the heart alters cardiac output by increasing heart rate and contractility?
|151. Cardiac output is equal to which of the following?
|152. If stroke volume is 80 mL and the heart rate is 70 beats per minute, what is the cardiac output?
|153. Patients with diastolic heart failure would present with ____________________
|154. Which of these events will happen if the connection between the SA node and the AV node becomes blocked?
|155. Which of these statements describes why the heart valves open and close?
|Enter the appropriate word(s) to complete the statement.|
|156. Compared to cardiac muscle tissue, skeletal muscle tissue has a(n) ____________________ duration for its refractory period.|
|157. An increase in the length of the cardiac muscle fibres prior to contraction ____________________ the stroke volume.|
|158. Ninety-nine percent of the cardiac fibres are specialized for ____________________ whereas the remainder are specialized for ____________________.|
|159. An increase in cardiac sympathetic activity ____________________ the velocity of impulse conduction through the heart.|
|160. An increase in heart rate ____________________ the cardiac output.|
|161. An increase in the parasympathetic activity ____________________ the AV-nodal delay.|
|162. An increase in venous return ____________________ the end-diastolic volume.|
|163. An increase in parasympathetic activity ____________________ the rate of depolarization of the SA node.|
|164. An increase in cardiac sympathetic activity ____________________ the stroke volume.|
|165. The ____________________ ensures that atrial excitation and contraction are complete before ventricular excitation and contraction commence.|
|166. A(n) ____________________ is a clot attached to the wall of a vessel.|
|167. An increase in stroke volume ____________________ the cardiac output.|
|168. ____________________ is the insufficient circulation of oxygenated blood to cardiac muscle in order to maintain its aerobic metabolism.|
|169. An increase in parasympathetic activity ____________________ the stroke volume.|
|170. An increase in cardiac sympathetic activity ____________________ the permeability of the SA node to K ions.|
|171. An increase in cardiac sympathetic activity ____________________ the rate of depolarization of the SA node.|
|172. During exercise, the cardiac output ____________________.|
|173. An increase in venous return ____________________ the stroke volume.|
|174. The ____________________ is the volume of blood in the ventricle when ejection is complete.|
|175. An increase in cardiac sympathetic activity ____________________ the contractility of the ventricles.|
|176. Vitamins ____________________ and ____________________ have been shown to slow plaque deposition.|
|177. A swishy murmur heard between the second and first heart sounds is indicative of a(n) ____________________ (stenotic or insufficient) ____________________ (AV or semilunar) valve.|
|178. ____________________ carries cholesterol to cells, whereas ____________________ transports it away from cells.|
|179. The ____________________ is the volume of blood in the ventricle when filling is complete.|
|180. The ____________________ is the normal pacemaker of the heart.|
|181. The extent of myocardial infarction is dependent on ____________________ and ____________________.|
|182. The ____________________ is the volume of blood pumped by each ventricle/minute.|
|183. The ____________________ is the volume of blood pumped by each ventricle/beat.|
|184. An increased ESV ____________________ the stroke volume.|
|185. The ____________________ is the difference between cardiac output at rest and maximal CO.|
|186. An increase in parasympathetic activity ____________________ the atrial contractility.|
|187. An increase in the end-diastolic volume ____________________ the stroke volume.|
|188. The ____________________ extracts cholesterol from the blood and converts it into ____________________, which are secreted into the bile.|
|189. PAF is released from the ____________________ lining of vessels.|
|190. An increase in parasympathetic activity ____________________ the heart rate.|
|191. The condition in which the pericardial sac becomes distended with excess fluid to the point that it impinges upon cardiac filling is known as ____________________.|
|192. The ____________________ are the kinds of blood vessels that experience congestion for congestive heart failure.|
|Match the cardiovascular features, labelled a. through d., with their correct characteristic.
|193. consists of abnormal smooth muscle cells, cholesterol deposits, scar tissue, and possible calcium deposits plaque|
|194. referred cardiac pain|
|195. freely floating clot|
|196. abnormal clot attached to a vessel wall|
|Match the effects with sympathetic or parasympathetic stimulation (or neither) of the heart. (Options may be used more than once or not at all.)
|197. increases the heart rate|
|198. decreases the contractility of the atrial muscle|
|199. increases the AV nodal delay|
|200. decreases the rate of depolarization to threshold of the SA node|
|201. increases the contractility of the atrial and ventricular muscle|
|202. decreases the contractility of the ventricular muscle|
|Match the factor involved in the initiation and spread of cardiac excitation, labelled a. through d. with the description. (Options may be used more than once or not at all.)
|203. has the fastest rate of pacemaker activity|
|204. allows the impulse to spread from cell to cell|
|205. delays conduction of the impulse|
|206. the only point of electrical contact between the atria and ventricles|
|207. the normal pacemaker of the heart|
|208. rapidly conducts the impulse down the ventricular septum and throughout much of the ventricular musculature|
|Match the EKG features, labelled a. through f., with their correct characteristic.
|209. ventricular depolarization|
|210. time during which ventricles are contracting and emptying|
|211. atrial depolarization|
|212. time during which atria are repolarizing|
|213. time during which impulse is travelling through the AV node|
|214. time during which ventricles are filling|
|215. ventricular repolarization|
|Match the pressure relationships, labelled a. through e., with the times in question. (Options may be used more than once or not at all.)
|216. during ventricular diastole|
|217. when the atrioventricular valve closes|
|218. during isovolumetric ventricular contraction|
|219. when the aortic valve opens|
|220. when ventricular ejection is occurring|
|221. when the aortic valve closes|
|222. during isovolumetric ventricular relaxation|
|223. when the atrioventricular valve opens|
|Match the anatomical structures, labelled a. through e., with the heart characteristics. (Options may be used more than once or not at all.)
|224. contains Purkinje|
|225. its cells have slow Ca2+ channels|
|226. the ventricles’ left is much thicker|
|227. its fast Ca2+ channels help initiate|
|228. during systole, it is forced closed by papillary muscle action|
|229. overcomes the afterload of the circuits|
|230. its closing partially creates the heart sound “lub”|
|231. contraction of this generates blood pressure|
|232. electrically connects the atria to the ventricles|
|Match the terms, labelled a. through f., with the descriptions. (Options may be used more than once or not at all.)
|233. The volume of blood ejected by each ventricle each minute is known as the _____.|
|234. The two main determinants of cardiac output are stroke volume and _____.|
|235. The volume of blood ejected by each ventricle each beat is known as the _____.|
|236. The stroke volume may be calculated by end-diastolic volume minus _____.|
|237. The maximum volume of blood that the ventricle contains after filling is complete is the _____.|
|238. The minimum volume of blood that the ventricle contains after emptying is complete is the _____.|
|239. Stroke volume can be increased by increasing end-diastolic volume and _____.|
|240. The number of times the heart contracts each minute is the_____.|
|241. Heart rate can be increased by increasing _____.|
|Match the valve abnormalities, labelled a. and b., with the descriptions. (Options may be used more than once or not at all.)
|242. produces a “gurgling” murmur|
|243. produces a “whistling” murmur|
|244. valve does not close completely|
|245. valve does not open completely|
|Match the ions, labelled a. through c., with the events being described. (Options may be used more than once or not at all.)
|246. Inactivation of _____ channels brings about the slow drift of membrane potential to threshold in the cardiac autorhythmic cells.|
|247. Explosive increase in membrane permeability to _____ brings about the rapidly rising phase of the action potential in contractile cardiac cells.|
|248. Slow inward diffusion of _____ is largely responsible for the plateau portion of the cardiac action potential.|
|249. The rapid falling phase of the cardiac action potential is brought about primarily by the outward diffusion of _____.|
|250. Changes in cytosolic _____ concentration bring about changes in the strength of cardiac contraction.|
|251. Parasympathetic stimulation increases the permeability of the SA node to _____, whereas sympathetic stimulation decreases the permeability to this same ion.|
|Match the term, labelled a. through g., with their correct characteristic.
|252. encircles the heart and secretes a lubricating fluid|
|253. carries cholesterol to cells|
|254. prevents backflow of blood|
|255. area of low electrical resistance that allows an action potential to spread from one cardiac cell to surrounding cells|
|256. muscle mass that becomes excited and contracts as a unit|
|257. induces coronary vasodilation|
|258. carries cholesterol away from cells|
|259. What is the proper sequence of blood flow through the circulatory system?1. right atrium 6. pulmonary vein2. left atrium 7. lungs3. right ventricle 8. systemic tissues4. left ventricle 9. aorta5. pulmonary artery 10. venae cavae|
|260. Compare the magnitude of the items in question by using the answer code (options may be used more than once or not at all):a. A is greater than Bb. B is greater than Ac. A and B are equalA. resistance and pressure in the pulmonary circulationB. resistance and pressure in the systemic circulationA. volume of blood pumped out by the left side of the heartB. volume of blood pumped out by the right side of the heartA. spontaneous rate of depolarization in the SA nodeB. spontaneous rate of depolarization in the ventriclesA. velocity of impulse through the bundle of His and Purkinje systemB. velocity of impulse conduction through the AV nodeA. rate of depolarization of the SA node on parasympathetic stimulationB. rate of depolarization of the SA node on sympathetic stimulationA. duration of systole at resting heart rateB. duration of systole at rapid heart rate during exerciseA. duration of diastole at resting heart rateB. duration of diastole at rapid heart rate during exerciseA. rate of ventricular filling in early diastoleB. rate of ventricular filling in late diastoleA. stroke volume when end-diastolic volume equals 130 mLB. stroke volume when end-diastolic volume equals 160 mLA. normal stroke volumeB. stroke volume on sympathetic stimulationA. volume of blood in the ventricles at the onset of isovolumetric ventricular contractionB. volume of blood in the ventricles at the end of isovolumetric ventricular contractionA. volume of blood in the left ventricle when the aortic valve opensB. volume of blood in the left ventricle when the aortic valve closesA. volume of blood in the left ventricle when the left AV valve opensB. volume of blood in the left ventricle when the left AV valve closesA. duration of the refractory period in cardiac muscleB. duration of contraction in cardiac muscleA. duration of the refractory period in cardiac muscleB. duration of the refractory period in skeletal muscleA. coronary blood flow during systoleB. coronary blood flow during diastole|
|261. Indicate the proper order of the events during the cardiac cycle by placing numbers in the blanks preceding the events in sequence. The first and last events are already indicated as a guide. 1__ AV valve open; aortic valve closed; ventricular filling occurring_____ blood ejected from the ventricle_____ isovolumetric ventricular relaxation_____ atrial contraction_____ aortic valve opens_____ SA node discharges_____ ventricular filling complete_____ ventricular relaxation begins_____ aortic valve closes_____ isovolumetric ventricular contraction_____ ventricular contraction begins; AV valve closes_12__ AV valve opens; ventricular filling occurs again; one cardiac cycle is complete|
|262. Describe the primary factors that influence cardiac output.|
|263. Compare and contrast intrinsic and extrinsic controls of cardiac activity.|
|264. Describe generation of pacemaker action potentials and the cardiac conduction pathway.|
|265. Describe the cardiac cycle.|
|266. Describe the mechanism of decompensated heart failure.|
|267. How does hypertension influence heart activity?|
|158. contraction; conducting the action potentialinitiating; conducting the action potential|
|165. AV nodal delay|
|169. has no effect on|
|174. end-systolic volume|
|176. A; CC; A|
|177. insufficient; semilunar|
|178. LDL; HDL|
|179. end-diastolic volume|
|180. SA node|
|181. the size of the occluded vessel; the extent of collateral circulationthe extent of collateral circulation; the size of the occluded vessel,|
|182. cardiac output|
|183. stroke volume|
|185. cardiac reserve|
|188. liver, bile salts|
|191. cardiac tamponade|
|259. 10, 1, 3, 5, 7, 6, 2, 4, 9, 8|
|260. b, c, a, a, b, c, a, a, b, b, c, a, b, c, a, b|
|261.1, 9, 3, 5, 8, 4, 6, 2, 10, 7, 11, 12|
|262. Answers will vary.|
|263. Answers will vary.|
|264. Answers will vary.|
|265. Answers will vary.|
|266. Answers will vary.|
|267. Answers will vary.|