full file at http://testbankcorner.eu Exam Name _ MULTIPLE CHOICE Choose the one alternative that best completes the statement or answers the question 1) What is the role of calcium ions in muscle contraction? A) increase levels of myoglobin B) reestablish glycogen stores C) bind to regulatory sites on troponin to remove contraction inhibition D) form hydroxyapatite crystals Answer: C Explanation: A) B) C) D) 2) Of the following muscle types, which has only one nucleus, no sarcomeres, and rare gap junctions? A) cardiac muscle B) multiunit smooth muscle C) skeletal muscle D) visceral smooth muscle Answer: B Explanation: 3) A) B) C) D) 4) Rigor mortis occurs because A) the cells are dead B) sodium ions leak into the muscle causing continued contractions C) proteins are beginning to break down, thus preventing a flow of calcium ions D) no ATP is available to release attached actin and myosin molecules Answer: D Explanation: 2) A) B) C) D) 3) Which of the following is not a connective tissue sheath that wraps individual muscle fibers? A) perimysium B) epimysium C) aponeurosis D) endomysium Answer: C Explanation: 1) A) B) C) D) 4) full file at http://testbankcorner.eu 5) When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods? A) relaxation period B) latent period C) refractory period D) fatigue period Answer: C Explanation: A) B) C) D) 6) What is the functional role of the T tubules? A) hold cross bridges in place in a resting muscle B) enhance cellular communication during muscle contraction C) stabilize the G and F actin D) synthesize ATP to provide energy for muscle contraction Answer: B Explanation: 6) A) B) C) D) 7) In an isotonic contraction, the muscle A) rapidly resynthesizes creatine phosphate and ATP B) changes in length and moves the "load" C) never converts pyruvate to lactate D) does not change in length but increases tension Answer: B Explanation: 7) A) B) C) D) 8) An anaerobic metabolic pathway that results in the production of two net ATPs per glucose plus two pyruvic acid molecules is A) the citric acid cycle B) glycolysis C) the electron transport chain D) hydrolysis Answer: B Explanation: 8) A) B) C) D) 9) The contractile units of skeletal muscles are A) myofibrils B) T tubules C) mitochondria Answer: A Explanation: 5) A) B) C) D) D) microtubules 9) full file at http://testbankcorner.eu 10) Which of the following is not a component of the standard treatment for muscle strain? A) elevation of the limb B) rest of the muscle C) ice on the muscle D) stretching of the muscle Answer: D Explanation: A) B) C) D) 11) Which muscle cells have the greatest ability to regenerate? A) skeletal B) cardiac C) no muscle can regenerate D) smooth Answer: D Explanation: 13) A) B) C) D) 14) What is the primary function of wave summation? A) produce smooth, continuous muscle contraction B) prevent muscle fatigue C) prevent muscle relaxation D) increase muscle tension Answer: A Explanation: 12) A) B) C) D) 13) Which of the following statements is most accurate? A) The I band lengthens during isotonic contraction B) Muscle tension remains relatively constant during isotonic contraction C) T tubules may be sliding during isotonic contraction D) Myofilaments slide during isometric contractions Answer: B Explanation: 11) A) B) C) D) 12) Which of the following is a factor that affects the velocity and duration of muscle contraction? A) load on the fiber B) number of muscle fibers stimulated C) size of the muscle fibers stimulated D) muscle length Answer: A Explanation: 10) A) B) C) D) 14) full file at http://testbankcorner.eu 15) Smooth muscle is characterized by all of the following except A) there are more thick filaments than thin filaments B) it appears to lack troponin C) there are noncontractile intermediate filaments that attach to dense bodies within the cell D) there are no sarcomeres Answer: A Explanation: A) B) C) D) 16) Which of the following statements is false or incorrect? A) Cardiac muscle contracts when stimulated by its own autorhythmic muscle cells B) Cardiac muscle fibers depend mostly on anaerobic cellular respiration to generate ATP C) Under normal resting conditions, cardiac muscle tissue contracts and relaxes about 75 times per minute D) Cardiac muscle fibers can use lactic acid to make ATP Answer: B Explanation: 17) A) B) C) D) 18) During vigorous exercise, there may be insufficient oxygen available to completely break down pyruvic acid for energy As a result, the pyruvic acid is converted to A) hydrochloric acid B) a strong base C) lactic acid D) stearic acid Answer: C Explanation: 16) A) B) C) D) 17) After nervous stimulation stops, what prevents ACh in the synaptic cleft from continuing to stimulate contraction? A) the action potential stops going down the overloaded T tubules B) acetylcholinesterase destroying the ACh C) calcium ions returning to the terminal cisternae D) the tropomyosin blocking the myosin once full contraction is achieved Answer: B Explanation: 15) A) B) C) D) 18) full file at http://testbankcorner.eu 19) Most skeletal muscles contain A) a predominance of fast oxidative fibers C) muscle fibers of the same type Answer: D Explanation: B) a predominance of slow oxidative fibers D) a mixture of fiber types A) B) C) D) 20) What produces the striations of a skeletal muscle cell? A) a difference in the thickness of the sarcolemma B) the T tubules C) the sarcoplasmic reticulum D) the arrangement of myofilaments Answer: D Explanation: 20) A) B) C) D) 21) Hypothetically, if a muscle were stretched to the point where thick and thin filaments no longer overlapped, A) cross bridge attachment would be optimum because of all the free binding sites on actin B) maximum force production would result because the muscle has a maximum range of travel C) ATP consumption would increase because the sarcomere is "trying" to contract D) no muscle tension could be generated Answer: D Explanation: D) fascicle 22) A) B) C) D) 23) Immediately following the arrival of the stimulus at a skeletal muscle cell there is a short period called the period during which the neurotransmitter is released by exocytosis, diffuses across the synaptic cleft, and binds to its receptors A) relaxation B) latent C) refractory D) contraction Answer: B Explanation: 21) A) B) C) D) 22) Which of the following surrounds the individual muscle cell? A) endomysium B) perimysium C) epimysium Answer: A Explanation: 19) A) B) C) D) 23) full file at http://testbankcorner.eu 24) The muscle cell membrane is called the A) sarcolemma B) epimysium Answer: A Explanation: C) perimysium D) endomysium A) B) C) D) 25) The term aponeurosis refers to A) the bands of myofibrils B) the rough endoplasmic reticulum C) the tropomyosin-troponin complex D) a sheetlike indirect attachment to a skeletal element Answer: D Explanation: 25) A) B) C) D) 26) Which of the following is not a role of ionic calcium in muscle contraction? A) activates epinephrine released from adrenal gland B) triggers neurotransmitter secretion C) removes contraction inhibitor D) binds with troponin Answer: A Explanation: D) hemoglobin 27) A) B) C) D) 28) During muscle contraction, myosin cross bridges attach to which active sites? A) actin filaments B) myosin filaments C) Z discs D) thick filaments Answer: A Explanation: 26) A) B) C) D) 27) The oxygen-binding protein found in muscle cells is A) myoglobin B) immunoglobin C) ATP Answer: A Explanation: 24) A) B) C) D) 28) full file at http://testbankcorner.eu 29) Excitation-contraction coupling requires which of the following substances? A) Ca2+ only B) ATP only C) ATP and glucose D) Ca2+ and ATP Answer: D Explanation: A) B) C) D) 30) Muscle tone is A) the condition of athletes after intensive training B) the feeling of well-being following exercise C) a state of sustained partial contraction D) the ability of a muscle to efficiently cause skeletal movements Answer: C Explanation: 32) A) B) C) D) 33) Three discrete types of muscle fibers are identified on the basis of their size, speed, and endurance Which of the following athletic endeavors best represents the use of red fibers? A) gym climbing B) a long, relaxing swim C) playing baseball or basketball D) a sprint by an Olympic runner Answer: B Explanation: 31) A) B) C) D) 32) The major function of the sarcoplasmic reticulum in muscle contraction is to A) provide a source of myosin for the contraction process B) regulate intracellular calcium concentration C) make and store phosphocreatine D) synthesize actin and myosin myofilaments Answer: B Explanation: 30) A) B) C) D) 31) What structure in skeletal muscle cells functions in calcium storage? A) myofibrillar network B) mitochondria C) intermediate filament network D) sarcoplasmic reticulum Answer: D Explanation: 29) A) B) C) D) 33) full file at http://testbankcorner.eu 34) The giant protein titin maintains the organization of the assisting in muscle stretching A) M line B) Z disc C) I band D) A band Answer: D Explanation: A) B) C) D) 35) Which of the following describes the cells of unitary smooth muscle? A) They are used for vision and hair raising B) They exhibit spontaneous action potentials C) They depend upon recruitment using the autonomic nervous system D) They consist of muscle fibers that are structurally independent of each other Answer: B Explanation: 37) A) B) C) D) 38) Fatigued muscle cells that recover rapidly are the products of A) slow exercise of short duration B) intense exercise of short duration C) intense exercise of long duration D) slow exercise of long duration Answer: B Explanation: 36) A) B) C) D) 37) Myoglobin A) is a protein involved in the direct phosphorylation of ADP B) stores oxygen in muscle cells C) produces the end plate potential D) breaks down glycogen Answer: B Explanation: 35) A) B) C) D) 36) What is the most distinguishing characteristic of muscle tissue? A) the ability to transform chemical energy into mechanical energy B) the diversity of activity of muscle tissue C) the ability to respond to nervous stimulation D) the design of the fibers Answer: A Explanation: 34) A) B) C) D) 38) full file at http://testbankcorner.eu 39) Which of the following is the correct sequence of events for muscle contractions? A) motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments B) neurotransmitter release, motor neuron action potential, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke C) neurotransmitter release, muscle cell action potential, motor neuron action potential, release of calcium ions from SR, sliding of myofilaments, ATP-driven power stroke D) muscle cell action potential, neurotransmitter release, ATP-driven power stroke, calcium ion release from SR, sliding of myofilaments Answer: A Explanation: A) B) C) D) 40) Muscle tissue has all of the following properties except A) secretion B) contractility C) excitability Answer: A Explanation: D) extensibility 41) A) B) C) D) 42) Creatine phosphate functions in the muscle cell by A) inducing a conformational change in the myofilaments B) storing energy that will be transferred to ADP to resynthesize ATP C) forming a chemical compound with actin D) forming a temporary chemical compound with myosin Answer: B Explanation: 40) A) B) C) D) 41) What part of the sarcolemma contains acetylcholine receptors? A) end of the muscle fiber B) motor end plate C) part adjacent to another muscle cell D) any part of the sarcolemma Answer: B Explanation: 39) A) B) C) D) 42) full file at http://testbankcorner.eu 43) What does excess postexercise oxygen consumption represent? A) the difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used B) amount of oxygen needed for aerobic activity to accomplish the same amount of work C) the amount of oxygen equal to the oxygen already used D) the amount of oxygen taken into the body immediately after the exertion Answer: A Explanation: A) B) C) D) 44) What is the functional unit of a skeletal muscle called? A) a myofibril B) a sarcomere C) the sarcoplasmic reticulum D) a myofilament Answer: B Explanation: 45) A) B) C) D) 46) Which of the following statements is true? A) Cardiac muscle cells are found in the heart and large blood vessels B) Smooth muscle cells have T tubules C) Cardiac muscle cells have many nuclei D) Striated muscle cells are long and cylindrical with many nuclei Answer: D Explanation: 44) A) B) C) D) 45) Which of the choices below does not describe how excess postexercise oxygen consumption (oxygen deficit) restores metabolic conditions? A) replaces the oxygen removed from myoglobin B) converts lactic acid back into glycogen stores in the liver C) resynthesizes creatine phosphate and ATP in muscle fibers D) increases the level of lactic acid in the muscle Answer: D Explanation: 43) A) B) C) D) 10 46) full file at http://testbankcorner.eu Figure 9.2 Using Figure 9.2, match the following: 66) I band 66) Answer: C Explanation: 17 full file at http://testbankcorner.eu Figure 9.1 Using Figure 9.1, match the following: 67) Individual muscle fiber 67) Answer: C Explanation: 68) Connective tissue surrounding muscle fiber bundles 68) Answer: E Explanation: 69) Only muscle cells are always multinucleated 69) Answer: skeletal Explanation: 70) Briefly explain the sources of energy for a one-minute sustained muscle contraction Answer: The first 4-6 seconds of energy come from stored ATP in the muscle cell 6-15 seconds of energy come from the transfer of creatine phosphate and ADP (which come from the first few seconds of burn) to form additional ATP 15-60 seconds of energy come from glycolysis, which by now has begun full production of ATP from glucose Explanation: 18 70) full file at http://testbankcorner.eu Figure 9.2 Using Figure 9.2, match the following: 71) A band 71) Answer: D Explanation: 72) How is it that norepinephrine (NE) can inhibit smooth muscle action in airways, yet stimulate contractions in smooth muscles everywhere else in the body? 72) Answer: Norepinephrine's effects depend upon the action of the receptor to which it binds.There is a different type of NE receptor on bronchiolar muscle than the NE receptor in other places Explanation: 73) How the three muscle types respond to being stretched? 73) Answer: All three muscle types initially respond by contracting more forcefully, then relaxing However, smooth muscle possesses a latch state in which it can maintain its new length while relaxed Explanation: 74) Compare red and white muscles relative to their speed of action and endurance 74) Answer: Red muscles tend to have a slow (oxidative) rate and fatigue resistance, whereas white muscle cells have a fast (oxidative) rate and fatigue easily Explanation: 75) Briefly, what causes rigor mortis? 75) Answer: Following the death of an individual, ATP is rapidly consumed and cannot be replaced Because cross bridge detachment and calcium active transport is ATP driven, calcium leakage from the sarcoplasmic reticulum causes attachment of cross bridges, and lack of ATP prevents detachments Explanation: 19 full file at http://testbankcorner.eu 76) Which cells help repair injured skeletal muscle fibers and allow regeneration of dead skeletal muscle? 76) Answer: satellite cells Explanation: Figure 9.1 Using Figure 9.1, match the following: 77) Connective tissue covering the exterior of a muscle organ 77) Answer: A Explanation: 78) What is a muscle spasm? 78) Answer: It is a sudden, involuntary twitch in smooth or skeletal muscle, possibly due to chemical imbalances Explanation: 79) Skeletal muscles have two special inclusions that help them perform their function of movement What are the two special inclusions of skeletal muscle cells and how would they be useful to the cell? Answer: Skeletal muscle cells require a lot of rapidly available fuel to burn in order to function properly They also require a lot of oxygen to burn this fuel efficiently Glycosomes store glycogen that can be quickly converted to glucose, which in turn can be burned to produce ATP Myoglobin is a chemical much like hemoglobin in blood cells that can store large quantities of oxygen Explanation: 20 79) full file at http://testbankcorner.eu 80) Only muscle cells commonly branch 80) Answer: cardiac Explanation: Figure 9.1 Using Figure 9.1, match the following: 81) Connective tissue sheath surrounding individual muscle fibers 81) Answer: B Explanation: TRUE/FALSE Write 'T' if the statement is true and 'F' if the statement is false 82) During isometric contraction, the energy used appears as movement Answer: True Explanation: False 83) An increase in the calcium ion level in the sarcoplasm starts the sliding of the thin filaments When the level of calcium ions declines, sliding stops Answer: True Explanation: 83) False 84) The effect of a neurotransmitter on the muscle cell membrane is to modify its ion permeability properties temporarily Answer: True Explanation: 82) False 21 84) full file at http://testbankcorner.eu 85) Muscle cells store more creatine phosphate than ATP resulting in the muscle having a reserve source of energy Answer: True Explanation: False 86) A resting potential is caused by a difference in the concentration of certain ions inside and outside the cell Answer: True Explanation: 89) False 90) Cardiac muscle has a limited regenerative capacity Answer: True Explanation: 94) False 95) Muscle contraction will always promote movement of body parts regardless of how they are attached Answer: True Explanation: 93) False 94) A contraction in which the muscle does not shorten but its tension increases is called isometric contraction Answer: True Explanation: 92) False 93) A motor neuron and all the muscle cells that it stimulates are referred to as a motor end plate Answer: True Explanation: 91) False 92) One of the functions of skeletal muscle contraction is production of heat Answer: True Explanation: 90) False 91) Once a motor neuron has fired, all the muscle fibers in a muscle contract Answer: True Explanation: 88) False 89) Peristalsis is characteristic of smooth muscle Answer: True Explanation: 87) False 88) Smooth muscles relax when intracellular Ca2+ levels drop but may not cease contractions Answer: True Explanation: 86) False 87) Eccentric contractions are more forceful than concentric contractions Answer: True Explanation: 85) False 22 95) full file at http://testbankcorner.eu 96) When a muscle fiber contracts, the I bands diminish in size, the H zones disappear, and the A bands not diminish in length Answer: True Explanation: False 97) The thin filaments (actin) contain a polypeptide subunit G actin that bears active sites for myosin attachment Answer: True Explanation: 100) False 101) Cells of unitary smooth muscle are found in the longitudinal and circular muscle layers of the intestine Answer: True Explanation: 99) False 100) The force of muscle contraction is controlled by multiple motor unit summation or recruitment Answer: True Explanation: 98) False 99) Although there are no sarcomeres, smooth muscle still possesses thick and thin filaments Answer: True Explanation: 97) False 98) Muscle tone is the small amount of tautness or tension in the muscle due to weak, involuntary contractions of its motor units Answer: True Explanation: 96) 101) False MATCHING Choose the item in column that best matches each item in column Match the following: 102) Diffusion across the cell membrane results in depolarization A) Acetylcholinesterase Answer: B B) Sodium ions 103) Destroys ACh C) Acetylcholine Answer: A 104) A neurotransmitter released at motor end plates by the axon terminals 102) 103) 104) Answer: C Match the following: 105) The myosin filaments are located in the A) A band Answer: A 23 105) full file at http://testbankcorner.eu Match the following: 106) The situation in which contractions become stronger due to stimulation before complete relaxation occurs Answer: B A) Tetanus 106) B) Wave summation 107) Continued sustained smooth contraction due to rapid stimulation 107) Answer: A Match the following: 108) Serves as the actual "trigger" for muscle contraction by removing the inhibition of the troponin molecules A) Calcium ions 108) Answer: A Match the following: 109) Both actin and myosin are found in the A) A band 109) Answer: A Match the sport to the energy system primarily used to perform the activity: 110) Weight lifting A) Direct phosphorylation Answer: A 110) Match the following: 111) The thicker filaments are the filaments A) Myosin 111) Answer: A Match the following: 112) Activate synaptic vesicles in axon terminals A) Calcium ions 112) Answer: A Match the following: 113) Depends on oxygen delivery and aerobic mechanisms A) Slow (oxidative), fatigue-resistant fibers Answer: A 24 113) full file at http://testbankcorner.eu Match the sport to the energy system primarily used to perform the activity: 114) Marathons Answer: B 115) 25 meter swim A) Anaerobic pathway 114) B) Aerobic pathway 115) Answer: A Match the following: 116) How a smooth increase in muscle force is produced A) Multiple motor unit summation 116) Answer: A Match the following: 117) Used to convert ADP to ATP by transfer of a high-energy phosphate group A reserve high-energy compound A) Creatine phosphate 117) Answer: A Match the following: 118) The contains only the actin filaments A) I band 118) Answer: A Match the following: 119) Have very fast-acting myosin ATPases and depend upon anaerobic metabolism during contraction A) Fast (oxidative or glycolytic), fatigable fibers 119) Answer: A Match the following: 120) Determined by alternating motor units of a muscle organ even when the muscle is at rest A) Muscle tone Answer: A 25 120) full file at http://testbankcorner.eu Match the following: 121) Contain abundant amounts of glycogen Answer: A 122) A relatively high percentage are found in successful marathon runners A) Fast (oxidative or glycolytic), fatigable fibers 121) B) Slow (oxidative), fatigue-resistant fibers 122) Answer: B 123) Red fibers, the smallest of the fiber types 123) Answer: B 124) Abundant in muscles used to maintain posture 124) Answer: B Match the following: 125) A sarcomere is the distance between two A) Z discs 125) Answer: A Match the following: 126) The stimulus above which no stronger contraction can be elicited, because all motor units are firing in the muscle A) Maximal stimulus 126) Answer: A ESSAY Write your answer in the space provided or on a separate sheet of paper 127) After much delayed removal of an elbow cast, Lauren noticed her arm was immovable What happened to her arm? Answer: Two things have occurred to Lauren while she was convalescing from her injury First, the immobilization of the arm caused some muscle mass to atrophy Second, the loss of muscle was replaced with tough connective tissue that locked her arm in place With therapy the tissue can be stretched or torn enough to return the full range of motion 128) Lynn has been waking up each night with intense pain in her calves She does not feel that it is serious enough to seek medical attention but would like to know what is causing the pain What would you tell her concerning this problem? She has been playing tennis all summer for several hours each day Could this have anything to with the night pain? Answer: This is due to sustained spasm, or tetanic contraction, of the gastrocnemius muscle The causes could be low blood sugar, electrolyte depletion (particularly sodium and calcium), dehydration, or irritability of the spinal cord neurons The fact that Lynn has been playing tennis for several hours each day may have caused an electrolyte depletion She should increase her intake of sodium and calcium 26 full file at http://testbankcorner.eu 129) A patient has no peristalsis in the gastrointestinal tract Explain a possible complication of this condition Answer: Peristalsis is wavelike movement produced by the circular and longitudinal muscle fibers of the intestinal walls that propels the intestinal contents forward Without peristalsis, the patient would be unable to expel his or her stool, leading to abdominal discomfort, then vomiting, and finally obstruction 130) The nurse encourages the patient to his own activities of daily living such as bathing, eating, dressing, and toileting activities How these activities promote physical conditioning? Answer: These activities are isotonic exercises in which muscle tension is constant and then shortens to produce muscle contraction and movement Because the muscles contract, the shape, size, and strength of the muscles are maintained as well as joint mobility 131) A patient is admitted for electroconvulsive treatment (ECT) The physician orders the neuromuscular blocking agent succinylcholine to reduce trauma by relaxing skeletal muscles Explain the process of muscle contraction and how a neuromuscular blocking agent such as succinylcholine would interfere with muscle contraction Answer: Muscle contraction begins with a stimulus to the nerve When the impulse reaches the neuromuscular junction, depolarization occurs, resulting in an influx of calcium ions from the extracellular fluid into the terminals, which then release a neurotransmitter, acetylcholine (ACh), into the cleft The ACh combines with receptor sites on the postjunctional muscle cell membrane, depolarizing it and facilitating the entry of sodium Neuromuscular blocking agents act at the motor end plate by competing with the ACh for the receptor sites, or by blocking depolarization 132) When a geriatric patient is admitted to the postsurgical unit, an important nursing measure is to prevent the loss of muscle mass What is the term used for loss of muscle mass and how can the patient prevent it? Answer: Disuse atrophy is degeneration and loss of muscle mass The size, shape, tone, and strength of muscles (including the heart) are maintained with mild exercise and increased with strenuous exercise Promoting exercise to maintain a patient's muscle tone, joint mobility, and cardiovascular function is an important nursing function 133) Aaron arrived at the hospital with the following symptoms: drooping eyelids; fatigue and weakness of his muscles; and difficulty talking, breathing, and swallowing What was his diagnosis? Answer: Aaron probably has myasthenia gravis (an autoimmune disease), which involves a shortage of ACh receptors at the neuromuscular junction 134) Gary was injured in an automobile accident that severed the motor neurons innervating his quadriceps Even though he has had extensive physical therapy, he is still suffering muscle atrophy Why is the therapy not working? Answer: In denervation atrophy, fibrous connective tissue replaces the muscle tissue that was lost When atrophy is complete, fibrous tissue cannot be reversed to muscle tissue 27 full file at http://testbankcorner.eu Answer Key Testname: C9 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) 15) 16) 17) 18) 19) 20) 21) 22) 23) 24) 25) 26) 27) 28) 29) 30) 31) 32) 33) 34) 35) 36) 37) 38) 39) 40) 41) 42) 43) 44) 45) 46) 47) 48) 49) 50) C B C D C B B B A D D A B A A B B C D D D A B A D A A A D C D B B D B A B B A A B B A B D D C A A D 28 full file at http://testbankcorner.eu Answer Key Testname: C9 51) 52) 53) 54) 55) 56) 57) 58) 59) 60) 61) 62) 63) 64) 65) 66) 67) 68) 69) 70) 71) 72) 73) 74) 75) 76) 77) 78) 79) 80) 81) 82) D B It is an inability of the muscle to contract despite continued stimulation Folds on the surface of smooth muscle cells that correspond to T tubules in skeletal muscle cells acetylcholinesterase B The ultimate switch is the enzyme acetylcholinesterase When the neuron stops releasing ACh, the muscle would not stop contracting if the acetylcholinesterase did not split the ACh into its two components, acetic acid and choline, making them release their binding sites E D contraction Muscle tension is the force exerted by a contracting muscle on an object The parts of the muscle triad are two adjacent SR terminal cisterns plus one intervening T tubule The sarcoplasmic reticulum is a reservoir for calcium ions in the cell's normal resting state The T tubule is a fold in the cell membrane between the sarcoplasmic reticuli When an impulse is activated by a motor neuron, the voltage-regulated change causes SR foot proteins to open Ca2+ channels The calcium ions are flushed out where they interact with the troponin complex to initiate a contraction Once the axon stops firing, the membrane polarity is quickly restored and the calcium ions are pulled off the troponin and attracted back into the sarcoplasmic reticulum insertion A tetanus C C E skeletal The first 4-6 seconds of energy come from stored ATP in the muscle cell 6-15 seconds of energy come from the transfer of creatine phosphate and ADP (which come from the first few seconds of burn) to form additional ATP 15-60 seconds of energy come from glycolysis, which by now has begun full production of ATP from glucose D Norepinephrine's effects depend upon the action of the receptor to which it binds.There is a different type of NE receptor on bronchiolar muscle than the NE receptor in other places All three muscle types initially respond by contracting more forcefully, then relaxing However, smooth muscle possesses a latch state in which it can maintain its new length while relaxed Red muscles tend to have a slow (oxidative) rate and fatigue resistance, whereas white muscle cells have a fast (oxidative) rate and fatigue easily Following the death of an individual, ATP is rapidly consumed and cannot be replaced Because cross bridge detachment and calcium active transport is ATP driven, calcium leakage from the sarcoplasmic reticulum causes attachment of cross bridges, and lack of ATP prevents detachments satellite cells A It is a sudden, involuntary twitch in smooth or skeletal muscle, possibly due to chemical imbalances Skeletal muscle cells require a lot of rapidly available fuel to burn in order to function properly They also require a lot of oxygen to burn this fuel efficiently Glycosomes store glycogen that can be quickly converted to glucose, which in turn can be burned to produce ATP Myoglobin is a chemical much like hemoglobin in blood cells that can store large quantities of oxygen cardiac B FALSE 29 full file at http://testbankcorner.eu Answer Key Testname: C9 83) 84) 85) 86) 87) 88) 89) 90) 91) 92) 93) 94) 95) 96) 97) 98) 99) 100) 101) 102) 103) 104) 105) 106) 107) 108) 109) 110) 111) 112) 113) 114) 115) 116) 117) 118) 119) 120) 121) 122) 123) 124) 125) 126) 127) TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE FALSE TRUE FALSE TRUE FALSE TRUE TRUE TRUE TRUE TRUE TRUE B A C A B A A A A A A A B A A A A A A A B B B A A Two things have occurred to Lauren while she was convalescing from her injury First, the immobilization of the arm caused some muscle mass to atrophy Second, the loss of muscle was replaced with tough connective tissue that locked her arm in place With therapy the tissue can be stretched or torn enough to return the full range of motion 30 full file at http://testbankcorner.eu Answer Key Testname: C9 128) This is due to sustained spasm, or tetanic contraction, of the gastrocnemius muscle The causes could be low blood sugar, electrolyte depletion (particularly sodium and calcium), dehydration, or irritability of the spinal cord neurons The fact that Lynn has been playing tennis for several hours each day may have caused an electrolyte depletion She should increase her intake of sodium and calcium 129) Peristalsis is wavelike movement produced by the circular and longitudinal muscle fibers of the intestinal walls that propels the intestinal contents forward Without peristalsis, the patient would be unable to expel his or her stool, leading to abdominal discomfort, then vomiting, and finally obstruction 130) These activities are isotonic exercises in which muscle tension is constant and then shortens to produce muscle contraction and movement Because the muscles contract, the shape, size, and strength of the muscles are maintained as well as joint mobility 131) Muscle contraction begins with a stimulus to the nerve When the impulse reaches the neuromuscular junction, depolarization occurs, resulting in an influx of calcium ions from the extracellular fluid into the terminals, which then release a neurotransmitter, acetylcholine (ACh), into the cleft The ACh combines with receptor sites on the postjunctional muscle cell membrane, depolarizing it and facilitating the entry of sodium Neuromuscular blocking agents act at the motor end plate by competing with the ACh for the receptor sites, or by blocking depolarization 132) Disuse atrophy is degeneration and loss of muscle mass The size, shape, tone, and strength of muscles (including the heart) are maintained with mild exercise and increased with strenuous exercise Promoting exercise to maintain a patient's muscle tone, joint mobility, and cardiovascular function is an important nursing function 133) Aaron probably has myasthenia gravis (an autoimmune disease), which involves a shortage of ACh receptors at the neuromuscular junction 134) In denervation atrophy, fibrous connective tissue replaces the muscle tissue that was lost When atrophy is complete, fibrous tissue cannot be reversed to muscle tissue 31 ... Explanation: 13 57) full file at http://testbankcorner.eu Figure 9.2 Using Figure 9.2, match the following: 58) M line 58) Answer: E Explanation: 14 full file at http://testbankcorner.eu Figure 9.1 Using... Explanation: 16 65) full file at http://testbankcorner.eu Figure 9.2 Using Figure 9.2, match the following: 66) I band 66) Answer: C Explanation: 17 full file at http://testbankcorner.eu Figure 9.1 Using... fibers of the intestinal walls that propels the intestinal contents forward Without peristalsis, the patient would be unable to expel his or her stool, leading to abdominal discomfort, then vomiting,