SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

Transcription

1 Exam Name SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Figure 9.1 Using Figure 9.1, match the following: 1) Endomysium. 2) Fascicle. 3) The tissue that binds muscles into functional groups. 4) Perimysium. 5) Muscle fiber. 1

2 Figure 9.2 Using Figure 9.2, match the following: 6) I band. 7) H zone. 8) A band. 9) Z disc. 10) M line MATCHING. Choose the item in column 2 that best matches each item in column 1. Match the following: 11) The stimulus above which no stronger contraction can be elicited, because all motor units are firing in the muscle. 12) Continued sustained smooth contraction due to rapid stimulation. A) Tetanus B) Multiple motor unit summation C) Maximal stimulus 13) How a smooth increase in muscle force is produced. 2

3 Match the following: 14) A sarcomere is the distance between two. 15) The contains only the actin filaments. 16) The thicker filaments are the filaments. A) Z discs B) Myosin C) I band D) A band 17) Both actin and myosin are found in the. 18) The myosin filaments are located in the. Match the following: 19) Serves as the actual "trigger" for muscle contraction by removing the inhibition of the troponin molecules. 20) A neurotransmitter substance released at motor end plates by the axonal endings. 21) A metabolic pathway that provides for a large amount of ATP per glucose because oxygen is used. Products are water and carbon dioxide and ATP. A) Creatine phosphate B) Acetylcholine C) Acetylcholinesterase D) Aerobic respiration E) Calcium ions 22) Normally stored in the terminal cisternae. 23) Used to convert ADP to ATP by transfer of a high-energy phosphate group. A reserve high-energy compound. 24) Destroys ACh. TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 25) The force of muscle contraction is controlled by multiple motor unit summation or recruitment. 26) A nerve cell and all the muscle cells that it stimulates are referred to as a motor end plate. 27) Peristalsis is characteristic of smooth muscle. 28) A contraction in which the muscle does not shorten but its tension increases is called isometric. 3

4 29) During isometric contraction, the energy used appears as movement. 30) One of the important functions of skeletal muscle is production of heat. 31) Oxygen debt refers to the oxygen required to make creatine phosphate. 32) Although there are no sarcomeres, smooth muscle still possesses thick and thin filaments. 33) When a muscle fiber contracts, the I bands diminish in size, the H zones disappear, and the A bands move closer together but do not diminish in length. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 34) Which muscle cells have the greatest ability to regenerate? A) smooth B) no muscle can regenerate C) skeletal D) cardiac 35) Which of the following is not a usual result of exercise? A) increase in the efficiency of the circulatory system B) increase in the number of muscle cells C) increase in the number of myofibrils within the muscle cells D) increase in the efficiency of the respiratory system 36) In muscle contraction, calcium apparently acts to: A) increase the action potential transmitted along the sarcolemma. B) cause ATP to bind to actin. C) remove the blocking action of tropomyosin. D) release the inhibition on Z discs. 37) Calcium ions bind to the molecule in skeletal muscle cells. A) tropomyosin B) troponin C) actin D) myosin 38) Myoglobin: A) holds a reserve supply of oxygen in muscle cells. B) produces the end plate potential. C) is a protein involved in the direct phosphorylation of ADP. D) breaks down glycogen. 39) An elaborate network of membranes in skeletal muscle cells that functions in calcium storage is the: A) mitochondria. B) intermediate filament network. C) myofibrillar network. D) sarcoplasmic reticulum. 4

5 40) A sarcomere is: A) the nonfunctional unit of skeletal muscle. B) the wavy lines on the cell seen in the microscope. C) the area between two intercalated discs. D) the area between two Z discs. 41) Creatine phosphate functions in the muscle cell by: A) forming a temporary chemical compound with myosin. B) forming a chemical compound with actin. C) storing energy that will be transferred to ADP to resynthesize ATP as needed. D) inducing a conformational change in the myofilaments. 42) After nervous stimulation of the muscle cell has ceased, the calcium: A) is actively pumped into the extracellular fluid for storage until the next contraction. B) is chemically bound to the filaments. C) level in the cytoplasm drops. D) is destroyed by cholinesterase. 43) The major function of the sarcoplasmic reticulum in muscle contraction is to: A) provide a source of myosin for the contraction process. B) synthesize actin and myosin myofilaments. C) make and store phosphocreatine. D) regulate intracellular calcium concentration. 44) The striations of a skeletal muscle cell are produced, for the most part, by: A) the T tubules. B) the sarcoplasmic reticulum. C) a difference in the thickness of the sarcolemma. D) the arrangement of myofilaments. 45) Which of the following are composed of myosin? A) all myofilaments B) thick filaments C) Z discs D) thin filaments 46) During muscle contraction, myosin cross bridges attach to which active sites? A) actin filaments B) Z discs C) myosin filaments D) thick filaments 47) Which of the following surrounds the individual muscle cell? A) perimysium B) fascicle C) epimysium D) endomysium 48) Rigor mortis occurs because: A) the cells are dead. B) proteins are beginning to break down, thus preventing a flow of calcium ions. C) ATP is required to release the attached actin and myosin molecules. D) sodium ions leak out of the muscle. 49) The oxygen-binding protein found in muscle cells is: A) ATP. B) immunoglobin. C) hemoglobin. D) myoglobin. 5

6 50) The contractile units of skeletal muscles are: A) T tubules. B) mitochondria. C) myofibrils. D) microtubules. 51) One functional unit of a skeletal muscle is: A) a myofibril. B) a myofilament. C) a sarcomere. D) the sarcoplasmic reticulum. 52) The functional role of the T tubules is to: A) synthesize ATP to provide energy for muscle contraction. B) stabilize the G and F actin. C) hold cross bridges in place in a resting muscle. D) enhance cellular communication during muscle contraction. 53) The role of calcium ions in muscle contraction is to: A) act as a third messenger. B) reestablish glycogen stores. C) initiate the conversion of carbon dioxide to oxygen for storage. D) bind to regulatory sites on troponin, changing the configuration. 54) Athletes sometimes complain of oxygen debt, a condition that results when insufficient oxygen is available to completely break down pyruvic acid. As a result, the pyruvic acid is converted to: A) hydrochloric acid. B) stearic acid. C) lactic acid. D) a strong base. 55) In an isotonic contraction, the muscle: A) does not change in length but increases tension. B) changes in length and moves the "load." C) never converts pyruvate to lactate. D) rapidly resynthesizes creatine phosphate and ATP. 56) The muscle cell membrane is called a(n): A) sarcolemma. B) endomysium. C) epimysium. D) perimysium. 57) The giant protein titin maintains the organization of the assisting in muscle stretching. A) M line B) Z disc C) A band D) I band 58) 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) hydrolysis. C) glycolysis. D) the electron transport chain. 59) Muscle tone is: A) the condition of athletes after intensive training. B) the feeling of well-being following exercise. C) the ability of a muscle to efficiently cause skeletal movements. D) a state of sustained partial contraction. 6

7 60) The sliding filament model of contraction involves: A) the shortening of thick filaments so that thin filaments slide past. B) the Z discs sliding over the myofilaments. C) actin and myosin shortening but not sliding past each other. D) actin and myosin sliding past each other but not shortening. 61) The first thing that stops a contraction after the nerve stops sending ACh is: A) calcium ions return to the terminal cisternae. B) the action potential stops going down the T tubule. C) acetylcholinesterase destroys the ACh, and they are removed from the membrane receptors. D) the tropomyosin blocks the myosin. 62) Theoretically, if a muscle were stretched to the point where thick and thin filaments no longer overlapped: A) ATP consumption would increase since the sarcomere is "trying" to contract. B) cross bridge attachment would be optimum because of all the free binding sites on actin. C) no muscle tension could be generated. D) maximum force production would result since the muscle has a maximum range of travel. 63) An individual has just ingested a chemical that binds irreversibly to the ACh receptors in the sarcolemma. By itself it does not alter membrane potential, yet prevents normal neurotransmitter binding. Ignoring the effects on any other system, the consequence to skeletal muscle would be: A) irreversible contraction as soon as the first nervous stimulation reached the sarcolemma. B) no contraction at all by nervous mechanisms. C) contraction if stimulated by an external electrode. D) no contraction at all by nervous mechanisms, but contraction if stimulated by an external electrode. SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 64) Only muscle cells are multinucleated. 65) The end of the muscle that moves when a muscle contracts is called the. 66) In the synaptic cleft of a neuromuscular junction, is always present. 67) The time in which cross bridges are active is called the period of. 68) Only muscle cells branch. 69) A smooth, sustained contraction is called. 70) Define muscle fatigue. 71) Briefly, what causes rigor mortis? 72) What ultimately stops a muscle contraction? 73) Briefly explain where the energy comes from in a one-minute sustained muscle contraction. 7

8 ESSAY. Write your answer in the space provided or on a separate sheet of paper. 74) 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? 75) 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? 76) 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 do with the night pain? 77) After removal of an elbow cast, Lauren noticed her arm was immovable. What happened to her arm? 78) When a geriatric client is admitted to the rehabilitation 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? 79) The nurse encourages the patient to do his own activities of daily living such as bathing, feeding, dressing and toileting activities. How do these activities promote physical conditioning? 80) A patient is admitted for electroconvulsive treatment (ECT). The physician orders the neuromuscular blocking agent metocurine iodide (metubine) to reduce trauma by relaxing skeletal muscles. Explain the process of muscle contraction and how a neuromuscular blocking agent such as metubine would interfere with muscle contraction. 8

9 Answer Key Testname: 9-MUSCLE-TISSUE-CONTR.TST SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 1) B 2) D 3) A 4) E 5) C 6) C 7) B 8) D 9) A 10) E MATCHING. Choose the item in column 2 that best matches each item in column 1. 11) C 12) A 13) B 14) A 15) C 16) B 17) D 18) D 19) E 20) B 21) D 22) E 23) A 24) C TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 25) TRUE 26) FALSE 27) TRUE 28) TRUE 29) FALSE 30) TRUE 31) FALSE 32) TRUE 33) TRUE MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 34) A 35) B 36) C 37) B 38) A 39) D 40) D 1

10 Answer Key Testname: 9-MUSCLE-TISSUE-CONTR.TST 41) C 42) C 43) D 44) D 45) B 46) A 47) D 48) C 49) D 50) C 51) C 52) D 53) D 54) C 55) B 56) A 57) C 58) C 59) D 60) D 61) C 62) C 63) D SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 64) skeletal 65) insertion 66) acetylcholinesterase 67) contraction 68) cardiac 69) tetanus 70) Fatigue occurs when ATP production fails to keep pace with ATP use even though the muscle still receives stimuli. 71) 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. 72) 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, acetyl and choline, making them release their binding sites. 73) 1. The first 4-6 seconds of energy come from stored ATP in the muscle cell 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 seconds of energy come from glycolysis which by now has begun full production of ATP from glucose. ESSAY. Write your answer in the space provided or on a separate sheet of paper. 74) 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. 75) Aaron probably has myasthenia gravis (an autoimmune disease), which involves a shortage of ACh receptors at the neuromuscular junction. 2

11 Answer Key Testname: 9-MUSCLE-TISSUE-CONTR.TST 76) 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 calcium. 77) 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. 78) 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. 79) 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. 80) 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 post junctional 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. 3