1. Skeletal muscle appears to be striated as a result of:
1. the sarcoplasmic reticulum extending through the fiber ina regular arangement
2. the different sheaths of connective tissue which warp aroundthe various fibers and fasciculi
3. The terminal cisternae being arranged at regular intervalsthroughout the fiber
4. the arrangement of actin and myosin filaments
5. the many nuclei in different sections throughout the cell
Answer4
2. Which arrangement of the components of a skeletal musclecell is in the correct order?
1. epimysium, perimysium, sarcolemma, endomysium, fasciculus
2. endomysium, myofibril, perimysium, fasciculus, sarcolemma
3. epimysium, perimysium, fasciculus, endomysium, sarcolemma
4. perimysium, sarcolemma, endomysium, fasciculus, myofibrils
5. sarcolemma, endomysium, fasciculus, myofibrils, perimysium
Answer3
3. As soon as a muscle contracts, ADP is converted back toATP by the action of the enzyme cholinesterase.
1. true
2. false
Answer2
4. Each motor unit contains the same number of muscle fibers.
5. Which of the following chemicals, when present in excess,contributes the most to muscle fatigue?
1. Acetylcholine
2. ATP
3. ADP
4. lactic acid
5. 1 and 4
6. Which of the following does not increase muscle performance(contraction)?
1. increasing temperature
2. increasing the rate of stimulus
3. decreasing the rate of stimulus
5. 3 and 4
Answer5
7. A twitch contraction:
1. is a continual mild or partial contraction
2. is a normal type of muscle contraction found in all musclesof the body
3. is a singular quick response to a single stimulus
4. is a very sustained muscle contraction
5. none of the above
8. A maximal stimulus:
1. is any stimulus that is less than a minimal stimulus
2. is the least stimulus that just produces a muscle response
3. is any stimulus that is greater than a minimal stimulus
4. is the continual mild or partial contraction of muscles
9. The time period from where a stimulus is applied until themuscle contracts is called the:
1. latent period
2. minimal stimulus
3. refractory period
4. absolute refractory period
Answer1
10. The duration of a twitch contraction is approximately:
1. 1/100 second
2. 1/1000 second
3. 1/10 second
4. 1/3 second
5. 3/4 second
11. In a treppe contraction:
1. successive muscular contractions are subtracted from theprevious one
2. the load that is moved by the muscle changes
3. the load that is moved by the muscle remains the same
4. the muscle produces tetanic contractions
5. successive muscular contractions increase in response torepeating stimuli
12. In an isotonic muscle contraction the load to be movedchanges and the extent of muscle movement remains the same.
13. The aerobic pathway is considered to be the fastest ATPproducing pathway found in muscle.
14. What is missing from the following equation?
phosphocreatine + ADP ----> ? + Creatine
1. ATP
2. acetic acid
3. lactic acid
4. phosphate
5. acetyl CoA
15. The alactic oxygen debt:
1. requires oxygen to oxidize lactic acid
2. requires oxygen for the resynthesis of phospho creatine
3. requires oxygen for the replacement of oxygen lost
4. 1 and 2
5. 2 and 3
16. The main source of energy for normal (aerobic) muscle contractionis:
1. fat
2. carbohydrate
3. fructose
4. protein
5. lactic acid
17. Slow twitch muscle fibers are about twice as large as fasttwitch fibers.
18. Slow twitch fibers contain more mitochondrion than fasttwitch fibers.
19. Which of the following is not a characteristic of the physiologicalchanges that occur in the muscles of the conditioned individual?
1. increase in myoglobin
2. increase in glycogen storage
3. increased storage of phosphocreatine
4. increase in muscle capillaries
5. increase in resting pulse rate
20. With increasing age there is gradual loss of muscle fibers.
21. What percentage of a female's body weight is muscle?
1. 50%
2. 75%
3. 25%
4. 45%
5. 10%
22. Each individual muscle fiber is surrounded by connectivetissue called:
1. sarcolemma
2. endomysium
3. perimysium
4. epimysium
5. endoneurium
23. The cytoplasm of a muscle cell is called the:
2. nucleoplasm
3. protoplasm
4. neuroplasm
5. sarcoplasm
24. Smooth muscle like skeletal muscle is multinucleated.
25. Muscle fibers are approximately _______ in diameter.
1. 10-100 mm
2. 1 mm
3. 10-100 u
4. 10-100 cm
5. 100 - 1000
26. Which of the following is the smallest in diameter:
1. actin filaments
2. myofibrils
3. muscle fibers
4. myosin filaments
27. A saromere is formed between two:
1. A bands
2. I bands
3. H zone
4. Z lines
28. The chemical transmitter that is released at the neuromuscularjunction is:
1. acetylcholinesterase
2. acetylcholine
3. epinephine
4. endorphin
5. GABA
29. The synaptic cleft (myoneural cleft) of the neuromuscularjunction is found:
1. within the sole foot
2. within the sarcoplasmic reticulum
3. between the cell membrane of the sole foot and the infoldedsarcolemma
4. between the sole foot and the motor end plate
5. 3 & 4
30. Curare:
1. stimulates muscle contraction
2. blocks calcium release
3. competes for acetylcholine receptor sites and thereby inhibitsmuscle contraction
4. blocks releasing acetylcholine
5. competes for acetycholine receptor sites and thereby facilitatesmuscle contraction
31. The calcium that is involved in muscular contraction isstored in the:
1. lateral sacs (terminal cisterna)
2. transverse tubules
3. longitudinal tubules
4. synaptic vesicles
5. sole foot
32. Rigor mortis results from:
1. excessive calcium buildup
2. excess ADP
3. bonds between myosin and actin which cannot be broken unlessan abundant supply of ADP is present
4. not enough ATP
5. in the synaptic cleft
33. Which of the following follows the all or none law?
1. whole muscle
2. muscle fiber
3. motor units
34. Which of the following is not the usual result of exercise?
1. increase in the number of muscle cells
2. increase in cardiovascular efficiency
3. decrease in the number of mitochondria
4. increase in efficiency of glycolytic and aerobic enzymesystems
5. 2 and 4
35. Myoglobin:
1. breaks down acetycholine
2. is directly responsible for muscle contraction
3. is highly concentrated at the motor end plate
4. holds a reserve supply of oxygen for use by muscle cells
36. A major function of the sarcoplasmic reticulum is:
1. make and store myoglobin
2. synthesize calcium
3. store phosphocreatine
4. store calcium and regulate its concentration within themuscle cell
5. store troponin
ANSWERS:
1-4, 2-3, 3-2, 4-2, 5-4, 6-5, 7-3, 8-5, 9-1, 10-3, 11-5, 12-2,13-2, 14-1, 15-5, 16-1, 17-2, 18-1, 19-5, 20-1, 21-3, 22-2, 23-5,24-2, 25-3, 26-1, 27-4, 28-2, 29-5, 30-3, 31-1. 32-4, 33-5, 34-3,35-4, 36-4