Physiology Muscle Self-Assessment PDF

Physiology Muscle Self-Assessment 1. Muscle tissue, one of the four principal types of tissue, consists chiefly of muscle cells that are highly specialized for: a) conduction b) contraction c) shortening d) lifting 2. Which of the following is NOT a type of muscle tissue? a) smooth b) cardia...

Physiology Muscle Self-Assessment 1. Muscle tissue, one of the four principal types of tissue, consists chiefly of muscle cells that are highly specialized for: a) conduction b) contraction c) shortening d) lifting 2. Which of the following is NOT a type of muscle tissue? a) smooth b) cardiac c) skeletal d) vascular 3. Skeletal muscle tissue forms skeletal muscles, organs that also contain each of the following, EXCEPT: a) connective tissues b) bones c) nerves d) blood vessels 4. Each cell in skeletal muscle tissue is a: a) single muscle fibre b) motor unit c) myofibril d) Purkinje fibre 5. Skeletal muscles perform each of the following functions, EXCEPT: a) maintain posture and body position b) guards entrances and exits c) moves contents of the digestive tract d) support soft tissues 6. During development, groups of ______________ fuse together to form individual skeletal muscle fibres. a) myoblasts b) myelinocytes c) myoglobins d) myotrophs 7. What is another name for the cell membrane of a muscle fibre? a) sarcolemma b) sarcoplasm c) sarcomere d) sarcolayer 8. Electrical impulses (action potentials) travel down _____________ into the muscle cells to efficiently trigger muscle fibre contraction. a) myoblastic (M) tubules b) transverse (T) tubules c) longitudinal (L) tubules d) contractile (C) tubules 9. What is the name for the cylindrical structures, which can actively shorten and thus are responsible for skeletal muscle fibre contraction? a) myosins b) myoplasms c) myocytes d) myofibrils 10. Myofibrils consist of bundles of ______________, which are protein filaments composed primarily of thin filaments and thick filaments. a) myolayers b) myofilaments c) myosins d) actins 11. The ______________________ is an intracellular membrane complex, containing Ca2+ ions. a) golgi apparatus (GA) b) sarcoplasmic reticulum (SR) c) nuclear envelope (NE) d) secretory apparatus (SA) 12. _____________ ions are released into the sarcoplasm on receiving electrical signals. a) calcium (Ca2+) b) potassium (K+) c) chloride (Cl-) d) hydrogen (H+) 13. Myofilaments are organized into repeating functional units called _______________________ and interactions between the thick and thin filaments of these functional units are responsible for muscle contraction. a) sarcofibrils b) myomeres c) myofibrils d) sarcomeres 14. A sarcomere contains each of the following except: a) thin filaments b) thick filaments c) proteins that regulate generation of thick and thin filaments d) proteins that stabilize the positions of thick and thin filaments 15. Visually, when viewed microscopically, the sarcomeres have a banding pattern of A bands (dark bands) with a ____________ at the centre. a) M line b) Z line c) A line d) I line 16. The ______________ marks the boundary between adjacent sarcomeres and is attached to thin filaments. a) Z line b) M line c) I line d) A line 17. In the _________________ thin filaments are situated between the thick filaments and they can slide across each other during contraction. a) Zone of Interaction b) Zone of Overlap c) Zone of Alignment d) Zone of Zinn 18. Strands of the protein ___________, which stretch from one Z line to the next M line, function to keep the thick and thin filaments in proper alignment, helps resist extreme stretching, and returns stretched muscles to resting length. a) nebulin b) titin c) troponin d) tropomyosin 19. A strand of the protein __________________ lies alongside thin filaments (and is attached to the M line), which helps align thin filaments of the sarcomere. a) titin b) tropomyosin c) troponin d) nebulin 20. Under resting conditions, interaction between thick and thin filaments and thus muscle fibre contraction is prevented by the ___________________ complex. a) actin-myosin b) troponin-tropomyosin c) actin-tropomyosin d) myosin-tropomyosin 21. Muscle fibre contraction involves the interaction of ______________ of the thick filaments with binding sites (active sites) on the thin filaments. a) actin heads b) myosin heads c) actin tails d) myosin tails 22. Which strands are part of the thin filament and function to cover active sites thus preventing actin-mysosin interaction? a) troponin b) titin c) tropomyosin d) nebulin 23. How many subunits does a troponin molecule have? a) 2 b) 3 c) 4 d) 5 24. When a skeletal muscle contracts: a) the H zones and I bands remain constant b) the zones of overlap remains constant c) the Z lines move further apart d) the width of the A band remains constant 25. During contraction, thin filaments slide towards the centre of each sarcomere alongside the thick filaments and sliding occurs in every sarcomere along a myofibril, thus the: a) muscle grows larger b) myofibril gets shorter c) myolemma gets contracted d) myoblast interactions increase 26. The model representing the physical changes that occur, which describes what happens to the sarcomere during contraction is called the: a) sliding filament theory b) moving fibre hypothesis c) shortening filament hypothesis d) contracting fibre theory 27. Normal skeletal muscle contraction only occurs when skeletal muscle fibres are activated by motor neurons resulting in so-called: a) stimulus-secretion coupling b) excitation-contraction coupling c) monomere-monomere coupling d) sarcomere-myofibril coupling 28. The first step in muscle contraction is the release of _________ into the sarcoplasm. a) calcium ions b) magnesium ions c) chloride ions d) potassium ions 29. After release from the sarcoplamic reticulum, ions then trigger interactions between ___________________________, resulting in muscle fibre contraction. a) sarcomeres and myofibrils b) thick and thin filaments c) actin and troponin d) nebulin and titin 30. Interactions during contraction produce __________________ and consume energy. a) distension b) tension c) swelling d) adenosine triphosphate (ATP) 31. When sarcomeres shorten in a contraction, they _________________ the muscle fibre: a) shorten b) release tension in c) metabolize d) support 32. __________________ produced by an individual muscle fibre, or indeed an entire skeletal muscle, can vary widely and can change moment to moment. a) adenosine triphosphate (ATP) b) tension c) radiation d) density changes 33. A muscle fibre is either contracting ("on") or relaxed ("off"), this is the ______________________ and when a fibre contracts it does so fully (although it may not shorten fully). a) on-off principle b) twitch-response principle c) all-or-none principle d) motor-unit principle 34. A single stimulus-contraction-relaxation sequence in a mucle fibre is called a twitch, which can be measured as a: a) myogram b) electrocardiogram (ECG) c) electroencephalogram (EEG) d) electrosarcogram (ESG) 35. Which of the following can NOT be used to describe part of a single twitch: a) latent period b) relaxation phase c) tetanic phase d) contraction phase 36. If a skeletal muscle is stimulated a second time immediately after the relaxation phase has ended the force will rise, if this happens repeatedly force rises like steps in a staircase, a phenomenon called: a) treppe b) complete tetanus c) incomplete tetanus d) twitching 37. If a second stimulus arrives before the relaxation phase has ended a second more powerful contraction occurs, which is referred to as: a) treppe b) wave summation c) complete tetanus d) temporal summation 38. _____________________ is induced in muscle when the stimulation rate is increased so much that the relaxation phase is completely eliminated. a) complete tetanus b) treppe c) incomplete tetanus d) temporal summation 39. Which of these is not one of the three major types of skeletal muscle fibre: a) slow b) fast c) intermediate d) resistant 40. What is generally considered in terms of power and endurance? a) muscle contraction b) muscle fibre classification c) fatigue d) muscle performance