Anatomy and Physiology 1 Chapter 10 self quiz Pro, Dima Darwish,MD. 1) Which of the following is a recognized function of skeletal muscle? A) produce movement B) maintain posture C) maintain body temperature D) guard body entrances and exits E) All of the answers are correct. 2) At each end of the muscle, the collagen fibers of the epimysium, perimysium, and endomysium, come together to form a A) tendon. B) satellite cell. C) ligament. D) tenosynovium. E) sheath. 3) The bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to bone is called a(n) A) fascicle. B) tendon. C) ligament. D) epimysium. E) myofibril. 4) A fascicle is a A) group of muscle fibers that are encased in the perimysium. B) layer of connective tissue that separates muscle from skin. C) group of muscle fibers that are all part of the same motor unit. D) group of muscle fibers and motor neurons. E) collection of myofibrils in a muscle fiber. 5) Interactions between actin and myosin filaments of the sarcomere are responsible for A) muscle fatigue. B) the conduction of neural stimulation to the muscle fiber. C) muscle contraction. D) muscle relaxation. E) the striped appearance of skeletal muscle.
6) The advantage of having many nuclei in a skeletal muscle fiber is the ability to A) contract much more forcefully. B) produce more ATP with little oxygen. C) store extra DNA for metabolism. D) produce large amounts of muscle proteins. E) produce nutrients for muscle contraction. 7) Which of the following best describes the term sarcomere? A) protein that accounts for elasticity of resting muscle B) repeating unit of striated myofibrils C) storage site for calcium ions D) thin filaments are anchored here E) largely made of myosin molecules 8) Which of the following best describes the term sarcoplasmic reticulum? A) protein that accounts for elasticity of resting muscle B) repeating unit of striated myofibrils C) storage and release site for calcium ions D) thin filaments are anchored here E) largely made of myosin molecules 9) Cross-bridges are portions of A) actin molecules. B) myosin molecules. C) troponin molecules. D) tropomyosin molecules. E) calcium ions. 10) At rest, active sites on the actin are blocked by A) myosin molecules. B) troponin molecules. C) tropomyosin molecules. D) calcium ions. E) ATP molecules. 11) All of the following proteins are part of the thin filaments except A) actin. B) tropomyosin. C) troponin. D) titin. E) None of the answers is correct; there are no exceptions.
12) In response to action potentials arriving along the transverse tubules, the sarcoplasmic reticulum releases A) acetylcholine. B) sodium ions. C) potassium ions. D) calcium ions. E) hydrogen ions. 13) Each skeletal muscle fiber is controlled by a motor neuron at a single A) synaptic knob. B) sarcomere. C) neuromuscular junction. D) synaptic cleft. E) transverse tubule. 14) In a sarcomere, cross-bridge attachment occurs specifically in the A) zone of overlap. B) A band. C) I band. D) M line. E) H band. 15) Active sites on the actin become available for binding after A) actin binds to troponin. B) troponin binds to tropomyosin. C) calcium binds to troponin. D) calcium binds to tropomyosin. E) myosin binds to troponin. 16) The action potential is conducted into a skeletal muscle fiber by A) motor end plates. B) neuromuscular junctions. C) transverse tubules. D) triads. E) sarcoplasmic reticulum. 17) The most important factor in decreasing the intracellular concentration of calcium ion after contraction is A) active transport of calcium across the sarcolemma. B) active transport of calcium into the sarcoplasmic reticulum.
C) active transport of calcium into the synaptic cleft. D) diffusion of calcium out of the cell. E) diffusion of calcium into the sarcoplasmic reticulum. 18) Which of the following become connected by myosin cross-bridges during muscle contraction? A) thin filaments and thick filaments B) thick filaments and titin filaments C) z disks and actin filaments D) thick filaments and t-tubules E) thin filaments and t-tubules 19) Triggering of the muscle action potential occurs after A) acetylcholine binds to chemically-gated channels in the motor end plate. B) acetylcholinesterase is released from synaptic vesicles into the synaptic cleft. C) calcium ion binds to channels on the motor end plate. D) the action potential jumps across the neuromuscular junction. E) Any of these can produce an action potential in the muscle cell. 20) After death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. This results in a condition known as A) tetany. B) treppe. C) depolarization. D) rigor mortis. E) oxygen debt. 21) The following is a list of the events that occur during a muscle contraction. What is the correct sequence of these events? 1. Myosin cross-bridges bind to the actin. 2. The free myosin head splits ATP. 3. Calcium ion is released from the sarcoplasmic reticulum. 4. The myosin head pivots toward the center of the sarcomere. 5. Calcium ion binds to troponin. 6. The myosin head binds an ATP molecule and detaches from the actin. A) 1, 3, 5, 4, 6, 2 B) 5, 1, 4, 6, 2, 3 C) 3, 5, 1, 2, 4, 6 D) 3, 5, 1, 4, 6, 2 E) 1, 4, 6, 2, 3, 5 22) When acetylcholine binds to receptors at the motor end plate, the sarcolemma becomes
A) more permeable to sodium ions. B) less permeable to sodium ions. C) more permeable to calcium ions. D) less permeable to potassium ions. E) less permeable to potassium and sodium ions. 23) The muscle weakness of myasthenia gravis results from A) insufficient acetylcholine release from presynaptic vesicles. B) loss of acetylcholine receptors in the end-plate membrane. C) the motor neuron action potential being too small to stimulate the muscle fibers. D) excessive acetylcholinesterase that destroys the neurotransmitter. E) inability of the muscle fiber to produce ATP. 24) When a muscle is stimulated repeatedly at a high rate, the amount of tension gradually increases to a steady maximum tension. This state of maximum tension is called A) incomplete tetanus. B) complete tetanus. C) a twitch. D) wave summation. E) recruitment. 25) A single motor neuron together with all the muscle fibers it innervates is called a(n) A) end foot. B) end plate. C) motor unit. D) dermatome. E) myotome. 26) A weight-lifter strains to lift a heavy weight and there is no movement of the person's arms holding on to the weight. This type of contraction is called a(n) contraction. A) isometric B) tetanus C) isotonic D) treppe E) concentric 27) In which of the following would the motor units have the fewest muscle fibers? A) muscles of the neck B) postural muscles of the back C) muscles that control the eyes D) thigh muscles
E) calf muscles 28) A resting muscle generates most of its ATP by A) hydrolysis of creatine phosphate. B) anaerobic respiration. C) aerobic metabolism of fatty acids. D) glycogenolysis. E) the tricarboxylic acid cycle. 29) Creatine phosphate A) is produced by the process of anaerobic respiration. B) can replace ATP in binding to myosin molecules during contraction. C) acts as an energy reserve in muscle tissue. D) is only formed during strenuous exercise. E) cannot transfer its phosphate group to ADP. 30) During the recovery period following exercise, all of the following are true except A) lactic acid is removed from muscle cells. B) the muscle actively produces ATP. C) muscle fibers are unable to contract. D) oxygen is consumed at above the resting rate. E) heat is generated. 31) The type of muscle fiber that is most resistant to fatigue is the fiber. A) fast B) slow C) intermediate D) anaerobic E) high-density 32) Fast fibers A) have low resistance to fatigue. B) rely on aerobic metabolism. C) have many mitochondria. D) have twitches with a very brief contraction phase. E) have low resistance to fatigue and quick twitches. 33) Muscles that move the eyeball have fibers. A) fast B) slow C) intermediate D) circular
E) All of the answers are correct. 34) Which of the following is not characteristic of smooth muscle? A) The striations are due to the orderly arrangement of actin and myosin. B) Neurons that innervate smooth muscles are under involuntary control. C) Smooth muscle cells are uninucleate. D) Smooth muscles do not contain sarcomeres. E) The thin filaments of smooth muscle fibers are attached to dense bodies. 35) Which of the following is not a function of smooth muscle tissue? A) altering the diameter of the respiratory passageways B) elevating hairs on the arm C) forcing blood from the heart into the major arteries D) moving food materials along the digestive tract E) forcing urine out of the urinary tract 36) The protein that regulates muscle contraction by controlling the availability of active sites on actin is called A) actin. B) titin. C) myosin. D) tropomyosin. E) nebulin. 37) The structural theory that explains how a muscle fiber contracts is called the theory. A) sliding filament B) excitation-contraction coupling C) neuromuscular D) muscle contraction E) action-myosin interaction 38) Active sites become exposed when calcium ions bind to A) tropomyosin. B) actin. C) myosin. D) troponin. E) calcium channels. 39) Cross bridge detachment is caused by binding to the myosin head.
A) ATP B) calcium C) magnesium D) acetylcholine E) acetylcholinesterase 40) An infection by the bacterium Clostridium tetani can cause the disease called A) cholera. B) polio. C) botulism. D) tetanus. E) muscular dystrophy. The assignment is due on Monday 11/24/2014 Best!