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Jugar Test
1. 
The thick filament is composed of what moledule?
A.
actin
B.
troponin
C.
myosin
D.
tropomyosin
2. 
The pivoting head of the myosin provides what is known as the
A.
power stroke
B.
recruitment
C.
ATP
D.
energy
3. 
What molecule in the thin filament has a binding site for myosin heads?
A.
tropomyosin
B.
troponin
C.
myosin
D.
actin
4. 
What molecule in the thin filament covers the binding site?
A.
tropomyosin
B.
troponin
C.
myosin
D.
actin
5. 
What molecule in the thin filament has a binding site for calcium ions?
A.
tropomyosin
B.
troponin
C.
myosin
D.
actin
6. 
What molecule must bind to the myosin head in order for it to disconnect with actin?
A.
ATP
B.
calcium ions
C.
thin filament
D.
sarcomere
7. 
Hydrolysis of ATP returns the myosin molecule to the ______ conformation.
A.
backsliding
B.
high energy
C.
relaxed
D.
latent
8. 
As the contraction cycle continues, alternate binding of myosin heads prevents the tin filament from
A.
backsliding
B.
high energy
C.
relaxed
D.
latent
9. 
What is NOT a role of ATP in the contraction of muscle?
A.
detach myosin from actin
B.
operate the calcium pump
C.
powers glycolosis
D.
power the working stroke
10. 
Which of the following shorten during contraction? (may be more than one)
A.
thick filament
B.
sarcomere
C.
thin filament
D.
H zone
11. 
What is a neuron that extends from the brain or spinal cord to a muscle or gland?
A.
sensory neuron
B.
motor neuron
C.
interneuron
D.
none of the above
12. 
What is a motor neuron and all the muscle fibers it innervates referred to as?
A.
motor unit
B.
skeletal muscles
C.
myofibril
D.
thin filament
13. 
The stimulation of additional motor units will increase the strength of the contraction. This process is called
A.
contraction
B.
twitch
C.
recruitment
D.
resorption
14. 
The development of tension in a muscle, in response to a single action potential, is called a/an
A.
contraction
B.
stimulus
C.
sarcomere
D.
twitch
15. 
The phase of a muscle twitch where sarcomeres shorten and increase in tension
A.
contraction period
B.
latent period
C.
relaxation period
D.
power stroke period
16. 
The phase of a muscle twitch where sarcomeres return to resting length and decrease in tension
A.
contraction period
B.
latent period
C.
relaxation period
D.
power stroke period
17. 
The phase of a muscle twitch where sarcomeres are at resting length and action potential propogates
A.
contraction period
B.
latent period
C.
relaxation period
D.
power stroke period
18. 
______ results from repeated stimulation of a muscle fiber.
A.
propogation
B.
glycolysis
C.
wave summation
D.
twitch
19. 
In wave summation, you must _____ the time interval between stimuli.
A.
increase
B.
decrease
C.
eliminate
20. 
When stimulus frequency is increased, but some relaxation still occurs this is called
A.
unfused tetanus
B.
fused tetanus
C.
wave summation
D.
contraction
21. 
Once stored ATP has been used, an immediate source of energy is
A.
glycolosis
B.
ATPase
C.
glucose
D.
creatine phosphate
22. 
One molecule of CP produces _______ ATP.
A.
one
B.
two
C.
many
D.
no
23. 
___ is the process that breaks down glucose.
A.
contraction
B.
resorption
C.
power stroke
D.
glycolosis
24. 
What are two products of the breakdown of glucose?
A.
glycolosis
B.
ATP
C.
pyruvate
D.
creatine phosphate
25. 
If oxygen is not available, pyruvate is converted to
A.
lactic acid
B.
glucose
C.
ATP
D.
myofibril
26. 
If oxygen is available, the process is known as ________ catabolism.
A.
unfused tetanus
B.
fused tetanus
C.
anaerobic
D.
aerobic
27. 
What are two sources of oxygen?
A.
myoglobin
B.
blood
C.
oxidative
D.
respiratory cells
28. 
What structure attaches muscles to bones?
A.
ligaments
B.
tendons
C.
thick filaments
D.
skeletal tissue
29. 
The whole muscles is composed of muscle cells (fibers) grouped in bundles called
A.
myoglobin
B.
perimysium
C.
epimysium
D.
fascicles
30. 
What connective tissue surrounds the whole muscle?
A.
endomysium
B.
epimysium
C.
perimysium
D.
fascicles
31. 
What connective tissue surrounds the fascicles?
A.
endomysium
B.
epimysium
C.
perimysium
D.
muscles
32. 
What connective tissue surrounds the muscle cell?
A.
endomysium
B.
epimysium
C.
perimysium
D.
fascicles
33. 
What is the plasma membrane of a cell?
A.
sarcolemma
B.
sarcoplasm
C.
sarcoplasmic reticulum
34. 
What is the endoplasmic reticulum of a cell?
A.
sarcolemma
B.
sarcoplasm
C.
sarcoplasmic reticulum
35. 
What is the intracellular fluid around organelles?
A.
sarcolemma
B.
sarcoplasm
C.
sarcoplasmic reticulum
36. 
What is part of the sarcoplasmic reticulum and stores calcium ions?
A.
T tubules
B.
terminal cisternae
C.
triad
37. 
What is part of the sarcolemma and carries action potential?
A.
T tubules
B.
terminal cisternae
C.
triad
38. 
What is the T tubule plus two terminal cisternae?
A.
T tubules
B.
terminal cisternae
C.
triad
39. 
Which of the following are true of the dark band?
A.
known as A band
B.
known as I band
C.
contains only thin filaments
D.
contains both thick and thin filaments
E.
defined by length of thick filament
F.
defined as distance between two thick filaments
40. 
Which of the following are true of the light band?
A.
known as A band
B.
known as I band
C.
contains only thin filaments
D.
contains both thick and thin filaments
E.
defined by length of thick filament
F.
defined as distance between two thick filaments
41. 
What bisects the I band and anchors the thin filaments?
A.
Sarcomere
B.
H zone
C.
A band
D.
Z-discs
42. 
What is the region between two Z-discs that is the functional unit of the skeletal muscle called?
A.
Sarcomere
B.
H zone
C.
A band
D.
Z-discs
43. 
What is the cylindrical organelle inside the muscle cells?
A.
fascicle
B.
myofilament
C.
myofibril
D.
muscle fiber (cell)
E.
muscle
44. 
Thousands of these bundled together compose a myrofibril
A.
fascicle
B.
myofilament
C.
myofibril
D.
muscle fiber (cell)
E.
muscle
45. 
Thin cylinders that are much longer than most cells
A.
fascicle
B.
myofilament
C.
myofibril
D.
muscle fiber (cell)
E.
muscle
46. 
Made up of muscle fibers or cells
A.
fascicle
B.
myofilament
C.
myofibril
D.
muscle fiber (cell)
E.
muscle
47. 
Made up of fascicles
A.
fascicle
B.
myofilament
C.
myofibril
D.
muscle fiber (cell)
E.
muscle
48. 
The synapses between a motor neuron and the muscle it innervates is called a/an
A.
neuromuscular junction
B.
axon
C.
myofibril
D.
sarcolemma
49. 
Synaptic vesicles in the axon terminal of a motor neuron contain what neurotransmitter
A.
ATP
B.
creatine phosphate
C.
acetylcholine
50. 
Binding a neurotransmitter to the receptors on the motor end plate opens what type of ion channels?
A.
calcium channels
B.
sodium channels
C.
axon channels
D.
ATP channels
51. 
Opening of the sodium channels leads to _____ of the motor end plate.
A.
contraction
B.
recruitment
C.
hydrolosis
D.
depolarization
52. 
As a result of depolarization, an action potential is propagated along the _______ of the muscle cell and down the _____ into the cell.
A.
Z discs; terminal cisternae
B.
dark band; fascicle
C.
sarcolemma; T tubules
53. 
Propagating action potential releases what ion from the terminal cisternae?
A.
potassium ions
B.
calcium ions
C.
sodium ions
D.
ATP
54. 
How is a neurotransmitter removed from the synaptic cleft?
A.
acetylcholinesterase
B.
ATP
C.
calcium ions
D.
choline phosphate
55. 
What type of muscle tissue is striated and under voluntary control?
A.
smooth
B.
skeletal
C.
cardiac
56. 
Muscle tissue has all of the following characteristics except
A.
secretion
B.
contractility
C.
excitability
57. 
Which of the following connective tissue layers surrounds a fascicle?
A.
endomysium
B.
epimysium
C.
perimysium
58. 
What is the functional unit of skeletal muscle?
A.
sarcomere
B.
myofiliment
C.
sarcoplasm
59. 
What structure in skeletal muscle stores calcium?
A.
mitochondria
B.
sarcoplasmic reticulum
C.
T-tubules
60. 
What type of ion channel opens at the neuromuscular junction which leads to the release of acetylcholine?
A.
voltage-gated Na channels
B.
voltage-gated Ca++ channels
C.
ligand-gated Ca++ channels
61. 
What prevents Ach in the synaptic cleft from continuing to stimulate contraction?
A.
calcium returning to the terminal cisternae
B.
Ach gets used up
C.
acetylcholineserate destroys Ach
62. 
When _____ gated ion channels at the motor end plate open, the interior of the cell becomes less negative, which is known as _____.
A.
ligand; depolarization
B.
ligand; repolarization
C.
voltage; depolarization
63. 
What ion exits the muscle cell returning the cell to its resting membrane potential?
A.
sodium
B.
potassium
C.
calcium
64. 
Excitation-contraction coupling requires:
A.
calcium only
B.
calcium and ATP
C.
ATP only
65. 
During muscle contraction which two filaments form cross bridges?
A.
actin and myosin
B.
troponin and tropomyosin
C.
myosin and troponin
66. 
What ion binds to regulatory sites on troponin to remove contraction inhibition?
A.
sodium
B.
potassium
C.
calcium
67. 
What protein blocks myosin binding sites on actin molecules preventing contraction?
A.
troponin
B.
tropomyosin
C.
actin
68. 
A motor neuron and all the muscle fibers it innervates is called a
A.
motor unit
B.
sarcomere
C.
functional unit
69. 
Wave summation produces
A.
smooth, continuous contractions
B.
increase muscle tension
C.
prevent fatigue
70. 
During an isometric contraction, the muscle
A.
shortens
B.
lengthens
C.
does not change length
71. 
Which fiber type depends on oxygen delivery and aerobic metabolism?
A.
type I fibers
B.
type II fibers
72. 
What molecule is stored in muscle and provides energy that can be transferred to ADP and resynthesize ATP?
A.
glucose
B.
creatine phosphate
C.
pyruvic acid
73. 
Which of the following statements about myofilaments is false?
A.
Both thick and thin filaments contain the contractile protein myosin.
B.
Thin filaments of skeletal muscle contain the regulatory proteins troponin and tropomyosin.
C.
Thick filaments contain the contractile protein myosin.
74. 
The tension in our muscles at rest, which helps to maintain posture and stabilize joints, is called
A.
treppe
B.
recruitment
C.
muscle tone
D.
there is no tension in muscles at rest