A&P Chapter 10 - Lecture Exam 2 Flashcards

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%

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.

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.

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

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.

7) This is the outermost layer of connective tissue surrounding a skeletal muscle.

a) tendon

b) ligament

c) endomysium

d) epimysium

e) perimysium

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

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

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.

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

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

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.

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.

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

16) The sarcoplasmic reticulum in skeletal muscle fibers is used for storing

a) oxygen.

b) ATP.

c) PO43-.

d) Na+.

e) Ca2+.

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.

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.

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.

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

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

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

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

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.

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.

26) What energizes the myosin head?

a) the actin filaments

b) calcium ions

c) potassium ions

d) ATP hydrolysis reaction

e) ADP synthesis

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

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

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.

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.

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

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.

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

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.

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.

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.

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

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.

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.

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.

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

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

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

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.

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.

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.

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

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

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

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

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

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

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

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

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.

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.

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

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

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

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.

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

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.

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

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

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

108) On which of the following proteins is the enzyme ATPase located?

a) actin

b) myosin

c) titin

d) dystrophin

e) troponin

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