front 1 1) How much of the total body weight of an average adult is muscle tissue? a) 20-30% b) 30-40% c) 40-50% d) 50-60% e) 60-70% | back 1 c) 40-50% |
front 2 3) The different types of muscle tissue differ from each other by a) microscopic anatomy. b) location. c) type of Control. d) both microscopic anatomy and location. e) All of these choices are correct. | back 2 e) All of these choices are correct. |
front 3 4) Which of the following is NOT a major function of muscle tissue? a) moving blood throughout the body b) generating heat through contractions c) stabilizing the movement of joints d) promoting movement of body structures e) Production of Vitamins. | back 3 e) Production of Vitamins. |
front 4 5) This is the property of muscle that gives it the ability to stretch without damage. a) electrical excitability b) contractility c) extensibility d) elasticity e) thermogenesis | back 4 c) extensibility |
front 5 6) In an isometric contraction the muscle develops tension but does not a) lengthen. b) widen. c) does not expend energy. d) conduct electrical current. e) exhibit elasticity. | back 5 a) lengthen. |
front 6 7) This is the outermost layer of connective tissue surrounding a skeletal muscle. a) tendon b) ligament c) endomysium d) epimysium e) perimysium | back 6 d) epimysium |
front 7 8) The type of tendon formed when the connective tissue elements of a skeletal muscle extend as a broad flat layer. a) perimysium b) deep fascia c) fascicle d) aponeurosis e) endomysium | back 7 d) aponeurosis |
front 8 9) How many arteries and veins usually accompany a single nerve penetrating a skeletal muscle? a) one artery and one or two veins b) two arteries and two veins c) three arteries and two veins d) one artery and three veins e) one artery and a varied amount of veins | back 8 a) one artery and one or two veins |
front 9 10) In neuromuscular junctions, synaptic vesicles containing acetylcholine are found suspended in the cytosol of a) myelin bulbs. b) neuromuscular bulbs. c) synaptic end bulbs. d) axon collateral bulbs. e) tubule bulbs. | back 9 c) synaptic end bulbs. |
front 10 11) After the fusion of myoblasts, the muscle fiber loses its ability to do what? a) grow b) lengthen c) contract d) go through cell division. e) all of the answer choices | back 10 d) go through cell division. |
front 11 12) Which of the following correctly lists the sequence of structures that action potentials must move through to excite skeletal muscle contraction? a) sarcolemma, axon of neuron, T tubules b) T tubules, sarcolemma, myofilament c) muscle fiber, axon of neuron, myofibrils d) axon of neuron, sarcolemma, T tubules e) myofibrils, myofilaments, mitochondria | back 11 d) axon of neuron, sarcolemma, T tubules |
front 12 13) The mitochondria in skeletal muscle fiber are arranged a) randomly throughout the sarcoplasm. b) in circles around the T-tubules. c) around the nuclei. d) in rows near the contractile muscle proteins. e) close to the sarcolemma. | back 12 d) in rows near the contractile muscle proteins. |
front 13 14) The contractile organelles of a skeletal muscle fiber are thread-like structures called a) myofibrils. b) myoglobin. c) mitochondria. d) Z discs. e) M lines. | back 13 a) myofibrils. |
front 14 15) Release of calcium from these structures triggers skeletal muscle contraction. a) myofibrils b) mitochondria c) terminal cisterns of sarcoplasmic reticulum d) T-tubules e) none of the answer choices | back 14 c) terminal cisterns of sarcoplasmic reticulum |
front 15 16) The sarcoplasmic reticulum in skeletal muscle fibers is used for storing a) oxygen. b) ATP. c) PO43-. d) Na+. e) Ca2+. | back 15 e) Ca2+. |
front 16 17) Which of the following regions of a sarcomere contain thin filaments? a) I band b) A band c) H zone d) Both I band and A band. e) All of these answer choices are correct. | back 16 d) Both I band and A band. |
front 17 18) Which of the following regions of the sarcomere contain thick filaments? a) zone of overlap b) A band c) H zone d) both A band and H zone e) All of these answer choices are correct. | back 17 e) All of these answer choices are correct. |
front 18 19) Myofibrils contain a) contractile proteins. b) regulatory proteins. c) structural proteins. d) all of these answers are correct. e) none of these answers are correct. | back 18 d) all of these answers are correct. |
front 19 20) Which of the following functions as a motor protein in all three types of muscle tissue? a) actin b) myosin c) troponin d) titin e) tropomyosin | back 19 b) myosin |
front 20 21) What regulatory proteins can be found in the thin filaments of skeletal muscle fibers? a) troponin and titin b) tropomyosin and troponin c) myosin and titin d) titin and tropomyosin e) tropomyosin and myosin | back 20 b) tropomyosin and troponin |
front 21 22) Which of the regions of a sarcomere contain titin? a) the A band only b) the H zone only c) the zone of overlap only d) from M line to Z disc e) the I band only | back 21 d) from M line to Z disc |
front 22 23) Which of the following proteins is used to reinforce the sarcolemma and to help transmit the tension generated by the sarcomeres to the tendons? a) troponin b) tropomyosin c) myosin d) actin e) dystrophin | back 22 e) dystrophin |
front 23 24) During muscle contraction by the sliding filament mechanism, thin filaments are pulled towards the a) Z disc. b) H zone. c) M line. d) A band. e) I band. | back 23 c) M line. |
front 24 25) Calcium ions are released from the sarcoplasmic reticulum into the cytosol a) at the beginning of a contraction. b) in response to acetylcholine binding to Ca2+ release channels. c) by active transport using Ca2+ pumps in the SR membrane. d) after the contraction ends. e) All of these answers are correct. | back 24 a) at the beginning of a contraction. |
front 25 26) What energizes the myosin head? a) the actin filaments b) calcium ions c) potassium ions d) ATP hydrolysis reaction e) ADP synthesis | back 25 d) ATP hydrolysis reaction |
front 26 27) Skeletal muscle contraction will continue to occur as long as the following chemicals are available in the cytosol of the muscle fiber. a) ATP and acetylcholine (ACh) b) calcium ions and ATP c) ACh and potassium ions d) sodium ions and ATP e) calcium and ACh | back 26 b) calcium ions and ATP |
front 27 28) To stimulate skeletal muscle contraction, acetylcholine must cross the neuromuscular junction and bind to receptors on the motor endplate. a) node of Ranvier b) synaptic cleft c) sarcolemma d) synaptic end bulb e) transverse tubule | back 27 b) synaptic cleft |
front 28 29) Which of the following are commonly used to produce ATP during skeletal muscle contraction? a) creatine phosphate b) anaerobic cellular respiration c) aerobic cellular respiration d) All of these choices are correct. e) None of these choices are correct. | back 28 d) All of these choices are correct. |
front 29 30) In skeletal muscles, the combined amounts of creatine phosphate and ATP provide enough energy for the muscle to contract maximally for approximately a) 15 seconds. b) 15 minutes. c) 1.5 minutes. d) 5 seconds. e) one minute. | back 29 a) 15 seconds. |
front 30 32) This consists of a somatic motor neuron and all the skeletal muscle fibers it stimulates. a) sarcomere b) motor unit c) neuromuscular junction d) muscle unit e) multi-unit smooth muscle | back 30 b) motor unit |
front 31 33) A brief contraction of all muscle fibers in a motor unit in response to a single action potential moving down the somatic motor neuron is known as a) isometric contraction. b) isotonic contraction. c) tetany. d) refractory period. e) twitch contraction. | back 31 e) twitch contraction. |
front 32 34) This is also referred to as the period of lost excitability in skeletal muscle fibers. a) refractory period b) contraction period c) latent period d) relaxation period e) wave summation | back 32 a) refractory period |
front 33 35) A period of sustained skeletal muscle contraction in which individual twitches cannot be detected is called a) unfused tetanus. b) muscle atrophy. c) flaccidity. d) fused tetanus. e) wave summation. | back 33 d) fused tetanus. |
front 34 36) Increasing the number of active motor units within a skeletal muscle is called a) wave summation. b) fused tetanus. c) motor unit recruitment. d) muscle tone. e) flaccidity. | back 34 c) motor unit recruitment. |
front 35 37) This is the least powerful type of skeletal muscle fiber. a) slow oxidative fiber b) fast oxidative fiber c) fast glycolytic fiber d) slow glycolytic fiber e) None of these choices. | back 35 a) slow oxidative fiber |
front 36 38) Which of the following microscopic structures is only found in the cardiac muscle tissue? a) myosin b) tropomyosin c) sarcomeres d) intercalated discs e) striations | back 36 d) intercalated discs |
front 37 39) Which of the following types of muscle tissue contract when excited by their own autorhythmic muscle fibers? a) cardiac muscle b) slow twitch oxidative skeletal muscle c) multi-unit smooth muscle d) fast twitch glycolytic skeletal muscle e) All of these choices are correct. | back 37 a) cardiac muscle |
front 38 40) Smooth muscle tone is maintained by the prolonged presence of cytosol? a) ATP b) calcium ions c) phosphate ions d) myoglobin e) None of these choices. | back 38 b) calcium ions |
front 39 41) Hyperplasia is a) an increase in the size of muscle fibers. b) a decrease in the size of muscle fibers. c) an increase in the number of muscle fibers. d) a decrease in the number of muscle fibers. e) none of these choices. | back 39 c) an increase in the number of muscle fibers. |
front 40 75) Which of the following disorders is characterized by the wasting away of muscles due to the progressive loss of myofibrils? a) muscular hypertrophy b) muscular atrophy c) fibromyalgia d) myasthenia gravis e) tremors | back 40 b) muscular atrophy |
front 41 76) Which of the following best describes the condition known as muscular hypertrophy? a) decrease in diameter of muscle fibers b) torn sarcolemmas and damaged myofibrils c) increase in diameter of muscle fibers d) actin and myosin remain attached by crossbridges and the muscle is rigid e) damaged neuromuscular junctions | back 41 c) increase in diameter of muscle fibers |
front 42 77) Which of the following is NOT seen in exercise-induced muscle damage? a) torn sarcolemmas b) damaged myofibrils c) sore muscles d) progressive degeneration of muscles e) disrupted Z-discs | back 42 d) progressive degeneration of muscles |
front 43 78) Which event does not occur during the onset of rigor mortis? a) Enzymes from lysosomes digest crossbridges. b) Cellular membranes become leaky. c) Myosin heads bind to actin. d) Calcium ions leak out of the sarcoplasmic reticulum. e) ATP synthesis ceases. | back 43 a) Enzymes from lysosomes digest crossbridges. |
front 44 79) Which is a correct sequence of events in the onset of rigor mortis? a) Cellular membranes become leaky -> myosin heads bind to actin -> calcium ions leak into the sarcoplasm -> muscles are in a state of rigidity. b) Cellular membranes become leaky -> calcium ions leak into the sarcoplasm -> myosin heads bind to actin -> muscles are in a state of rigidity. c) Myosin heads bind to actin -> cellular membranes become leaky -> calcium ions leak into the sarcoplasm -> muscles are in a state of rigidity. d) Calcium ions leak into the sarcoplasm -> cellular membranes become leaky -> myosin heads bind to actin -> muscles are in a state of rigidity. e) Calcium ions leak into the sarcoplasm -> myosin heads bind to actin -> muscles are in a state of rigidity -> cellular membranes become leaky. | back 44 b) Cellular membranes become leaky -> calcium ions leak into the sarcoplasm -> myosin heads bind to actin -> muscles are in a state of rigidity. |
front 45 80) An EMG can be used to determine each of the following except a) the source of muscle weakness. b) paralysis due to muscle malfunction. c) paralysis due to nerve supplying the muscle. e) diagnose certain muscle disorders like muscular dystrophy. f) find the precise location of a muscle tumor. | back 45 e) diagnose certain muscle disorders like muscular dystrophy. |
front 46 81) Which of the following is NOT a common side effect of creatine supplementation? a) decrease in the body’s own synthesis of creatine b) kidney dysfunction c) dehydration d) all of these choices e) rigor mortis | back 46 e) rigor mortis |
front 47 86) Which term or condition in characterized by a loss of muscle tone? a) spasticity b) flaccid paralysis c) spastic paralysis d) rigidity e) hypertonia | back 47 b) flaccid paralysis |
front 48 90) Which is a NOT a side-effect of anabolic steroid use by male athletes? a) sterility b) baldness c) diminished testosterone secretion d) deepening of the voice e) atrophy of testes | back 48 d) deepening of the voice |
front 49 91) Which is a NOT a side-effect of anabolic steroid use by female athletes? a) sterility b) baldness c) facial hair growth d) menstrual irregularities e) deepening of the voice | back 49 b) baldness |
front 50 92) Which of the following types of abnormal contractions of skeletal muscle may be caused by holding a position for a prolonged period? a) spasm b) fasciculation c) tremor d) fibrillation e) cramp | back 50 e) cramp |
front 51 93) Which of the following types of abnormal contractions of skeletal muscle is a rhythmic, involuntary, purposeless quivering or shaking movement? a) tetanus b) fasciculation c) tremor d) fibrillation e) cramp | back 51 c) tremor |
front 52 94) Which of the following types of abnormal contractions of skeletal muscle is caused by a twitch of an entire motor unit and is visible under the skin? a) tic b) fasciculation c) tremor d) fibrillation e) cramp | back 52 b) fasciculation |
front 53 95) Which of the following types of abnormal contractions of skeletal muscle is caused by a single muscle fiber, is spontaneous, and is not visible under the skin? a) tic b) fasciculation c) tremor d) fibrillation e) cramp | back 53 d) fibrillation |
front 54 96) A structural protein that is associated with thin filaments and serves to anchor the thin filament to the Z-disc is called a) nebulin. b) titin. c) myomesin. d) dystrophin. e) tropomyosin. | back 54 a) nebulin. |
front 55 97) Which of the following statements does NOT accurately describe aerobic cellular respiration in skeletal muscles? a) Pyruvic acid generated by glycolysis enters the mitochondria. b) O2 is essential. c) CO2 is produced as a waste product. d) Lactic acid is continually produced. e) Can be used to generate ATP from fats, proteins or carbohydrates. | back 55 d) Lactic acid is continually produced. |
front 56 98) After prolonged strenuous exercise has stopped, heavy breathing will often continue for several minutes in order to provide the oxygen needed to a) convert the lactic acid produced during exercise back into glycogen. b) resynthesize creatine phosphate. c) replace oxygen displaced from muscle myoglobin. d) All of these choices e) None of these choices | back 56 d) All of these choices |
front 57 99) Which of the following types of muscle tissue is capable of undergoing the stress-relaxation response when they are stretched? a) cardiac muscle fibers b) fast glycolytic fibers c) fast oxidative-glycolytic fibers d) slow oxidative fibers e) single-unit smooth muscle fibers | back 57 e) single-unit smooth muscle fibers |
front 58 100) Cross bridges are formed during muscle contraction when on the thick filaments binds to on the thin filaments. a) myosin; troponin b) myosin; actin c) actin; myosin d) actin; tropomyosin e) myosin; tropomyosin | back 58 b) myosin; actin |
front 59 101) In a neuromuscular junction, the effect of acetylcholine (ACh) binding to receptors on the motor end plate lasts only briefly due to a) rapid uptake of the ACh into the myofiber. b) endocytosis of the ACh receptor into the myofiber. c) rapid destruction of ACh in the synaptic cleft by acetylcholinesterase. d) rapid destruction of ACh in the synaptic cleft by monoamine oxidase. e) diffusion of the ACh out of the synaptic cleft. | back 59 c) rapid destruction of ACh in the synaptic cleft by acetylcholinesterase. |
front 60 102) During this period of a twitch contraction, the muscle action potential moves along the sarcolemma of the muscle cell and triggers calcium release into the sarcoplasm. a) latent period b) contraction period c) relaxation period d) absolute refractory period e) relative refractory period | back 60 a) latent period |
front 61 103) Which of following is a common characteristic of fast glycolytic (FG) skeletal muscle fibers? a) large amount of myoglobin. b) many mitochondria. c) low concentration of creatine kinase in the sarcoplasm. d) slow myosin ATPase. e) high amount of glycogen in the sarcoplasm. | back 61 e) high amount of glycogen in the sarcoplasm. |
front 62 104) Myasthenia Gravis is an autoimmune disorder that targets the ACh receptors at the NMJ and ultimately reduces the number of available receptors. Predict what happens if you treat the patient with a drug that inhibits the activity of acetylcholinesterase? a) prevent contraction b) weak contraction c) normal contraction d) Cause spasm e) none of these choices | back 62 c) normal contraction |
front 63 105) Leg muscles are predominantly composed of which type of muscle fiber? a) slow oxidative b) fast glycolytic c) fast oxidative-glycolytic d) slow glycolytic e) fast oxidative | back 63 c) fast oxidative-glycolytic |
front 64 107) Biceps are predominantly composed of this type of muscle fiber. a) slow oxidative b) fast glycolytic c) fast oxidative-glycolytic d) slow glycolytic e) fast oxidative | back 64 b) fast glycolytic |
front 65 108) On which of the following proteins is the enzyme ATPase located? a) actin b) myosin c) titin d) dystrophin e) troponin | back 65 b) myosin |
front 66 109) After several visits to the gym and serious “iron pumping” (strength training) you notice that your biceps have enlarged. Which one of the following has happened to your muscles? a) atrophy b) dystrophy c) hyperplasia d) hypertrophy e) heterotrophy | back 66 d) hypertrophy |