1. What are the characteristics of skeletal muscle?
a. Started
b. Voluntary
c. Attached to bone
2. What are the characteristics of cardiac muscle?
a. Started with intercalated discs
b. Involuntary
c. For the heart
3. What are the characteristics of smooth muscle?
a. Non striated
b. Involuntary
c. Hollow organs
4. What are the functions of muscle?
a. Body movement (inside and outside)
b. Stabilizing body position
c. Store and move substances
i. Sphincters - overflow storage and pump
d. Generate heat
i. Thermogenesis
5. What are the properties of muscles?
a. Excitability - response to stimuli by producing AP
b. Contractility - contracts when adequately stimulated
c. Extensibility - stretch
6. What is hypertrophy?
a. Increase in diameter of muscle fiber because increase in number of myofibrils
(stronger)
7. What is atrophy?
a. Disuse - loss of myofibrols
b. Denervation - loss of myofibrils which are slowly replaced by scar tissue
8. What is the thin filament?
a. Actin
9. What is the thick filament?
a. Myosin
10. What are the two functional sites of myosin?
a. Actin binding and ATP binding
11. What does tropomyosin do?
a. Blocks myosin binding site on actin
12. What does troponin do?
a. Holds tropomyosin in place, Ca needed to move
13. What are the structural proteins?
a. Titin
b. Alpha - actinin
c. Myomesin
d. Rebulin
, e. Dystrophin
14. What is duchenne muscular dystrophy?
a. Mutated gene for dystrophin
b. X linked disorder
c. Skeletal fibers rupture and die
d. Early death about 20 yrs old
15. What is the contraction cycle?
a. Atp hydrolysis
b. Attachment of myosin to actin
c. Power stroke
d. Detachment of myosin from actin
16. What does ATPase activity require?
a. Mg
17. Can you shorten a sarcomere in one power stroke?
a. No need multiple
18. What is asynchronous cycling?
a. Prevent slippage of filaments between power strokes, some myosin is always in
contact with actin
19. What is needed to relax a muscle?
a. ATP
20. What is rigor mortis?
a. No ATP so muscles cannot relax
b. About 3 to 4 hours after death, lasts about 24 hours
21. What is the motor end plate?
a. Muscle membrane
i. Junctional folds
ii. Nicotinic cholinergic receptors
22. What is the end plate potential?
a. AP generated at the muscle membrane
b. Large graded potential usually enough to cause AP
c. Always excitatory
d. Chemically gated ion channels
e. Sodium enters
f. Travels to adjacent sarcolemma (continuous depolarization)
23. Is there a refractory period for muscle AP?
a. No
b. Cna add and sum AP together
c. Sustained muscle contraction
d. Tetanus
24. When does muscle relaxation happen?
a. When AP cease
b. Calcium release channels close
c. CA ATPase pumps CA back into SR (active transport)
d. Ca cannot bind to troponin to tropomyosin blocks again
a. Started
b. Voluntary
c. Attached to bone
2. What are the characteristics of cardiac muscle?
a. Started with intercalated discs
b. Involuntary
c. For the heart
3. What are the characteristics of smooth muscle?
a. Non striated
b. Involuntary
c. Hollow organs
4. What are the functions of muscle?
a. Body movement (inside and outside)
b. Stabilizing body position
c. Store and move substances
i. Sphincters - overflow storage and pump
d. Generate heat
i. Thermogenesis
5. What are the properties of muscles?
a. Excitability - response to stimuli by producing AP
b. Contractility - contracts when adequately stimulated
c. Extensibility - stretch
6. What is hypertrophy?
a. Increase in diameter of muscle fiber because increase in number of myofibrils
(stronger)
7. What is atrophy?
a. Disuse - loss of myofibrols
b. Denervation - loss of myofibrils which are slowly replaced by scar tissue
8. What is the thin filament?
a. Actin
9. What is the thick filament?
a. Myosin
10. What are the two functional sites of myosin?
a. Actin binding and ATP binding
11. What does tropomyosin do?
a. Blocks myosin binding site on actin
12. What does troponin do?
a. Holds tropomyosin in place, Ca needed to move
13. What are the structural proteins?
a. Titin
b. Alpha - actinin
c. Myomesin
d. Rebulin
, e. Dystrophin
14. What is duchenne muscular dystrophy?
a. Mutated gene for dystrophin
b. X linked disorder
c. Skeletal fibers rupture and die
d. Early death about 20 yrs old
15. What is the contraction cycle?
a. Atp hydrolysis
b. Attachment of myosin to actin
c. Power stroke
d. Detachment of myosin from actin
16. What does ATPase activity require?
a. Mg
17. Can you shorten a sarcomere in one power stroke?
a. No need multiple
18. What is asynchronous cycling?
a. Prevent slippage of filaments between power strokes, some myosin is always in
contact with actin
19. What is needed to relax a muscle?
a. ATP
20. What is rigor mortis?
a. No ATP so muscles cannot relax
b. About 3 to 4 hours after death, lasts about 24 hours
21. What is the motor end plate?
a. Muscle membrane
i. Junctional folds
ii. Nicotinic cholinergic receptors
22. What is the end plate potential?
a. AP generated at the muscle membrane
b. Large graded potential usually enough to cause AP
c. Always excitatory
d. Chemically gated ion channels
e. Sodium enters
f. Travels to adjacent sarcolemma (continuous depolarization)
23. Is there a refractory period for muscle AP?
a. No
b. Cna add and sum AP together
c. Sustained muscle contraction
d. Tetanus
24. When does muscle relaxation happen?
a. When AP cease
b. Calcium release channels close
c. CA ATPase pumps CA back into SR (active transport)
d. Ca cannot bind to troponin to tropomyosin blocks again
