Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1)
What is the role of calcium ions in muscle contraction?
1)
A)
increase levels of myoglobin
B)
reestablish glycogen stores
C)
bind to regulatory sites on troponin to remove contraction inhibition
D)
form hydroxyapatite crystals
2)
Of the following muscle types, which has only one nucleus, no sarcomeres, and rare gap junctions?
2)
A)
cardiac muscle
B)
multiunit smooth muscle
C)
skeletal mu scle
D)
visceral smooth muscle
3)
Which of the following is not a connective tissue sheath that wraps individual muscle fibers?
3)
A)
perimysium
B)
epimysium
C)
aponeurosis
D)
endomysium
4)
Rigor mortis occurs because ________.
4)
A)
the cells are dead
B)
sodium ions leak into the muscle causing continued contractions
C)
proteins are beginning to break down, thus preventing a flow of calcium ions
D)
no ATP is available to release attached actin and myosin molecules
5)
When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods?
5)
A)
relaxatio n pe rio d
B)
latent period
C)
refractory period
D)
fatigue period
6)
What is the functional role o f the T tubules?
6)
A)
hold cross bridges in place in a resting muscle
B)
enhance cellular communication during muscle contraction
C)
stabilize the G and F actin
D)
synthesize ATP to provide energy for muscle contraction
7)
In an isoton ic contraction, the muscle ________.
7)
A)
rapidly resynthesizes creatine phosphate and ATP
B)
changes in length and moves the "load"
C)
never converts pyruvate to lactate
D)
does not change in length but increases tension
8)
An anaerobic metabolic pathway that results in the production of two net ATPs per glucose plus
two pyruvic acid molecules is ________.
8)
A)
the citric acid cycle
B)
glycolysis
C)
the electron transport chain
D)
hydrolysis
9)
The contractile units of skeletal muscles are ________.
9)
A)
myofibrils
B)
T tubules
C)
mitochondria
D)
microtubules
10)
Which of the following is not a component of the standard treatment for muscle strain?
10)
A)
elevation of the limb
B)
rest of the muscle
C)
ice on the muscle
D)
stretchi ng of the muscle
11)
Which muscle cells have the greatest ability to regenerate?
11)
A)
skeletal
B)
cardiac
C)
no muscle can regenerate
D)
smooth
12)
Which of the following is a factor that affects the velocity and duration of muscle
contraction?
12)
A)
load on the fiber
B)
number of muscle fibers stimulated
C)
size of the muscle fibers stimulated
D)
muscle length
13)
Which of the following statements is most accurate?
13)
A)
The I band lengthens during isotonic contraction.
B)
Muscle tension remains relatively constant during isotonic contraction.
C)
T tubules may be sliding during isotonic contraction.
D)
Myofilaments slide during isometric contractions.
14)
What is the primary function of wave summation?
14)
A)
produce smooth, continuous muscle contraction
B)
prevent muscle fatigue
C)
prevent muscle relaxation
D)
increase muscle tension
15)
Smooth muscle is characterized by all of the following except ________.
15)
A)
there are more thick filaments than thin filaments
B)
it appears to lack troponin
C)
there are noncontractile intermediate filaments that attach to dense bodies within the cell
D)
there are no sarcomeres
16)
Which of the following statements is false or incorrect?
16)
A)
Cardiac muscle contracts when stimulated by its own autorhythmic muscle cells.
B)
Cardiac muscle fibers depend mostly on anaerobic cellular respiration to generate ATP.
C)
Under normal resting conditions, cardiac muscle tissue contracts and relaxes about 75 times
per minute.
D)
Cardiac muscle fibers can use lactic acid to make ATP.
17)
After nervous stimulation stops, what prevents ACh in the synaptic cleft from continuing to
stimulate contraction?
17)
A)
the action potential stops going down the overloaded T tubules
B)
acetylcholinesterase destroying the ACh
C)
calcium ions returning to the terminal cisternae
D)
the tropomyosin blocking the myosin once full contraction is achieved
18)
During vigorous exercise, there may be insufficient oxygen available to completely break down
pyruvic acid for energy. As a result, the pyruvic acid is converted to ________.
18)
A)
hydrochloric acid
B)
a strong base
C)
lactic acid
D)
stearic acid
19)
Most skeletal muscles contain ________.
19)
A)
a predominance of fast oxidative fibers
B)
a predominance of slow oxidative fibers
C)
muscle fibers of the same type
D)
a mixture of fiber types
20)
What produces the striations of a skeletal muscle cell?
20)
A)
a difference in the thickness of the sarcolemma
B)
the T tubules
C)
the sarcoplasmic reticulum
D)
the arrangement of myofilaments
21)
Hypothetically, if a muscle were stretched to the point where thick and thin filaments no longer
overlapped, ________.
21)
A)
cross bridge attachment would be optimum because of all the free binding sites on actin
B)
maximum force production would result because the muscle has a maximum range of travel
C)
ATP consumption would increase because the sarcomere is "trying" to contract
D)
no muscle tension could be generated
22)
Which of the following surrounds the individual muscle cell?
22)
A)
endomysium
B)
perimysium
C)
epimysium
D)
fascicle
23)
Immediately following the arrival of the stimulus at a skeletal muscle cell there is a short period
called the ________ period during which the neurotransmitter is released by exocytosis, diffuses
across the synaptic cleft, and binds to its receptors.
23)
A)
relaxation
B)
latent
C)
refractory
D)
contraction
24)
The muscle cell membrane is called the ________.
24)
A)
sarcolemma
B)
epimysium
C)
perimysium
D)
endomysium
25)
The term aponeurosis refers to ________.
25)
A)
the bands of myofibrils
B)
the rough endoplasmic reticulum
C)
the tropomyosin-troponin complex
D)
a sheetlike indirect attachment to a skeletal element
26)
Which of the following is not a role of ionic calcium in muscle contraction?
26)
A)
activates epinephrine released from adrenal gland
B)
triggers neurotransmitter secretion
C)
removes contraction inhibitor
D)
binds with troponin
27)
The oxygen-binding protein found in muscle cells is ________.
27)
A)
myoglobin
B)
immunoglobin
C)
ATP
D)
hemoglobin
28)
During muscle contraction, myosin cross bridges attach to which active sites?
28)
A)
actin filaments
B)
myosin filaments
C)
Z discs
D)
thick filaments
29)
Excitation-contraction coupling requires which of the following substances?
29)
A)
Ca2+ only
B)
ATP only
C)
ATP and glucose
D)
Ca2+ and ATP
30)
Muscle tone is ________ .
30)
A)
the condition of athletes after intensive training
B)
the feeling of well-being following exercise
C)
a state of sustained partial contraction
D)
the ability of a muscle to efficiently cause skeletal movements
31)
What structure in skeletal muscle cells functions in calcium storage?
31)
A)
myofibrillar network
B)
mitochondria
C)
intermediate filament network
D)
sarcoplasmic reticulum
32)
The major function of the sarcoplasmic reticulum in muscle contraction is to ________.
32)
A)
provide a source of myosin for the contraction process
B)
regulate intracellular calcium concentration
C)
make and store phosphocreatine
D)
synthesize actin and myosin myofilaments
33)
Three discrete types of muscle fibers are identified on the basis of their size, speed, and endurance.
Which of the following athletic endeavors best represents the use of red fibers?
33)
A)
gym climbing
B)
a long, relaxing swim
C)
playing baseball or basketball
D)
a sprint by an Olympic runner
34)
The giant protein titin maintains the organization of the ________ assisting in muscle stretching.
34)
A)
M line
B)
Z disc
C)
I band
D)
A band
35)
Which of the following describes the cells of unitary smooth muscle?
35)
A)
They are used for vision and hair raising.
B)
They exhibit spontaneous action potentials.
C)
They depend upon recruitment using the autonomic nervous system.
D)
They consist of muscle fibers that are structurally independent of each other.
36)
What is the most distinguis hing characteristic of muscle tissue?
36)
A)
the ability to transform chemical energy into mechanical energy
B)
the diversity of activity of muscle tissue
C)
the ability to respond to nervous stimulation
D)
the design of the fibers
37)
Myoglobin ________.
37)
A)
is a protein involved in the direct phosphorylation of ADP
B)
stores oxygen in muscle cells
C)
produces the end plate potential
D)
breaks down glycogen
38)
Fatigued muscle cells that recover rapidly are the products of ________.
38)
A)
slow exercise of short duration
B)
intense exercise of short duration
C)
intense exercise of long duration
D)
slow exercise of long duration
39)
Which of the following is the correct sequence of events for muscle contractions?
39)
A)
motor neuron action potential, neurotransmitter release, muscle cell action potential, release
of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments
B)
neurotransmitter release, motor neuron action potential, muscle cell action potential, release
of calcium ions from SR, ATP-driven power stroke
C)
neurotransmitter release, muscle cell action potential, motor neuron action potential, release
of calcium ions from SR, sliding of myofilaments, ATP-driven power stroke
D)
muscle cell action potential, neurotransmitter r elease, ATP-driven power stroke, calcium ion
release from SR, sliding of myofilaments
40)
Muscle tissue has all of the following properties except ________.
40)
A)
secretion
B)
contractility
C)
excitability
D)
extensibility
41)
What part of the sarcolemma contains acetylcholine receptors?
41)
A)
end of the muscle fiber
B)
motor end plate
C)
part adjacent to another muscle cell
D)
any part of the sarcolemma
42)
Creatine phosphate functions in the muscle cell by ________.
42)
A)
inducing a conformational change in the myofilaments
B)
storing energy that will be transferred to ADP to resynthesize ATP
C)
forming a chemical compou nd with actin
D)
forming a temporary chemical compound with myosin
43)
What does excess postexercise oxygen consumption represent?
43)
A)
the difference between the amount of oxygen needed for totally aerobic muscle activity and
the amount actually used
B)
amount of oxygen needed for aerobic activity to accomplish the same amount of work
C)
the amount of oxygen equal to the oxygen already used
D)
the amount of oxygen taken into the body immediately after the exertion
44)
What is the functional unit of a skeletal muscle called?
44)
A)
a myofibril
B)
a sarcomere
C)
the sarcoplasmic reticulum
D)
a myofilament
45)
Which of the choices below does not describe how excess postexercise oxygen consumption
(oxygen deficit) restores metabolic conditions?
45)
A)
replaces the oxygen removed from myoglobin
B)
converts lactic acid back into glycogen stores in the liver
C)
resynthesizes creatine phosphate and ATP in muscle fibers
D)
increases the level of lactic acid in the muscle
46)
Which of the following statements is true?
46)
A)
Cardiac muscle cells are found in the heart and large blood vessels.
B)
Smooth muscle cells have T tubules.
C)
Cardiac muscle cells have many nuclei.
D)
Striated muscle cells are long and cylindrical with many nuclei.
47)
The mechanism of contraction in smooth muscle is different from skeletal muscle in that ________.
47)
A)
ATP energizes the sliding process
B)
actin and myosin interact by the sliding filament mechanism
C)
the site of calcium regulation differs
D)
the trigger for contraction is a rise in intracellular calcium
48)
Which of the following would be recruited later in muscle stimulation when contractile strength
increases?
48)
A)
motor units with larger, less excitable neurons
B)
many small motor units with the ability to stimulate other motor units
C)
motor units with the longest muscle fibers
D)
large motor units with small, highly excitable neurons
49)
Which of the following is true about smooth muscle?
49)
A)
Certain smooth muscle cells can actually divide to increase their numbers.
B)
Smooth muscle cannot stretch as much as skeletal muscle.
C)
Smooth muscle, in contrast to skeletal muscle, cannot synthesize or secrete any connective
tissue elements.
D)
Smooth muscle has well-developed T tubules at the site of invagination.
50)
The strongest muscle contractions are normally achieved by ________.
50)
A)
recruiting small and medium muscle fibers
B)
increasing stimulus above the threshold
C)
increasing stimulus above the treppe stimulus
D)
increasing the sti mulation up to the maximal stimulus
51)
What is the role of tropomyosin in skeletal muscles?
51)
A)
Tropomyosin serves as a contraction inhibitor by blocking the actin binding sites on the
myosin molecules.
B)
Tropomyosin is the chemical that activates the myosin heads.
C)
Tropomyosin is the receptor for the motor neuron neurotransmitter.
D)
Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the
actin molecules.
52)
The sliding filament model of contraction involves ________.
52)
A)
the Z discs sliding over the myofilaments
B)
actin and myosin sliding past each other and partially overlapping
C)
the shortening of thick filaments so that thin filaments slide past
D)
actin and myosin lengthening in order to slide past each other
53)
Define physiologic muscle fatigue.
53)
54)
What are caveolae?
54)
55)
In the synaptic cleft of a neuromuscular junction, an enzyme called ________ is always
present.
55)
Figure 9.2
56)
H zone.
56)
57)
What ultimately stops muscle stimulation when the motor neuron ceases firing?
57)
Figure 9.2
58)
M line.
58)
Figure 9.1
59)
Bundle of muscle cells surrounded by a perimysium
59)
60)
The time in which cross bridges are active is called the period of ________.
60)
61)
What is muscle tension?
61)
62)
What are the parts of the skeletal muscle triad and what are their functi ons?
62)
63)
The end of the muscle that typically moves when a muscle contracts is called the ________.
63)
64)
Z disc.
64)
65)
A smooth, sustained contraction from rapid stimulation is called ________.
65)
Figure 9.2
66)
I band.
66)
Figure 9.1
67)
Individual muscle fiber.
67)
68)
Connective tissue surrounding muscle fiber bundles
68)
69)
Only ________ muscle cells are always multinucleated.
69)
70)
Briefly explain the sources of energy for a one-minute sustained muscle contraction.
70)
Figure 9.2
71)
A band.
71)
72)
How is it that norepinephrine (NE) can inhibit smooth muscle action in airways, yet
stimulate contractions in smooth muscles everywhere else in the body?
72)
73)
How do the three muscle types respond to being stretched?
73)
74)
Compare red and white muscles relative to their speed of action and endurance.
74)
75)
Briefly, what causes rigor mortis?
75)
76)
Which cells help repair injured skeletal muscle fibers and allow regeneration of dead
skeletal muscle?
76)
77)
Connective tissue covering the exterior of a muscle organ.
77)
78)
What is a muscle spasm?
78)
79)
Skeletal muscles have two special inclusions that help them perform their function of
movement. What are the two special inclusions of skeletal muscle cells and how would
they be useful to the cell?
79)
80)
Only ________ muscle cells commonly branch.
80)
81)
Connective tissue sheath surrounding individual muscle fibers
81)
82)
During isometric contraction, the energy used appears as movement.
82)
83)
An increase in the calcium ion level in the sarcoplasm starts the sliding of the thin filaments. When
the level of calcium ions declines, sliding stops.
83)
84)
The effect of a neurotransmitter on the muscle cell me mbrane is to modify its ion permeability
properties temporarily.
84)
85)
Muscle cells store more creatine phosphate than ATP resulting in the muscle having a reserve
source of energy.
85)
86)
A resting potential is caused by a difference in the concentration of certain ions inside and outside
the cell.
86)
87)
Eccentric contractions are more forceful than concentric contractions.
87)
88)
88)
89)
Peristalsis is characteristic of smooth muscle.
89)
90)
Cardiac muscle has a limited regenerative capacity.
90)
91)
Once a motor neuron has fired, all the muscle fibers in a muscle contract.
91)
92)
One of the functions of skeletal muscle contraction is production of heat.
92)
93)
A motor neuron and all the muscle cells that it stimulates are referred to as a motor end plate.
93)
94)
A contraction in which the muscle does not shorten but its tension increases is called isometric
contraction.
94)
95)
Muscle contraction will always promote movement of body parts regardless of how they are
attached.
95)
96)
When a muscle fiber contracts, the I bands diminish in size, the H zones disappear, and the A
bands do not diminish in length.
96)
97)
The thin filaments (actin) contain a polypeptide subunit G actin that bears active sites for myosin
attachment.
97)
98)
Muscle tone is the small amount of tautness or tension in the muscle due to weak, involuntary
contractions of its motor units.
98)
99)
Although there are no sarcomeres, smooth muscle still possesses thick and thin filaments.
99)
100)
The force of muscle contraction is controlled by multiple motor unit summation or recruitment.
100)
101)
Cells of unitary smooth muscle are found in the longitudinal and circular muscle layers of the
intestine.
101)
results in depolarization.
end plates by the axon terminals.
102)
104)
the ______ __.
105)
Match the following:
become stronger d ue to stimulation
before complete relaxation occurs.
contraction due to rapid stimulation.
B)
Wave summation
106)
107)
muscle contraction by removing the
inhibition of the troponin molecules.
108)
________.
109)
110)
Weight lifting
A)
Direct phosphorylation
filaments.
111)
terminals.
112)
aerobic mechanisms.
113)
Match the sport to the energy sys tem primarily used to perform the activity:
114)
Marathons
115)
25 meter swim
A)
Anaerobic pathway
force is produced.
116)
transfer of a high-energy phosphate
group. A reserve high-energy
compound.
117)
filaments.
118)
ATPases and depend upon anaerobic
metabolism during contraction.
fibers
119)
of a muscle organ even when the
muscle is at rest.
120)
Match the following:
glycogen.
in successful marathon runners.
types.
posture.
fibers
121)
122)
123)
124)
two ________.
125)
contraction can be elicited, because all
motor units are firing in the muscle.
126)
127)
After much delayed removal of an elbow cast, Lauren noticed her arm was immovable. What happened to her
arm?
128)
Lynn has been waking up each night with intense pain in her calves. She does not feel that it is serious enough
to seek medical attention but would like to know what is causing the pain. What would you tell her concerning
this problem? She has been playing tennis all summer for several hours each day. Could this have anything to
do with the night pain?
129)
A patient has no peristalsis in the gastrointestinal tract. Explain a possible complication of this condition.
130)
The nurse encourages the patient to do his own activities of daily living such as bathing, eating, dressing, and
toileting activities. How do these activities promote physical conditioning?
131)
A patient is admitted for electroconvulsive treatment (ECT). The physician orders the neuromuscular blocking
agent succinylcholine to reduce trauma by relaxing skeletal muscles. Explain the process of muscle contraction
and how a neuromuscular blocking agent such as succinylcholine would interfere with muscle contraction.
132)
When a geriatric patient is admitted to the postsurgical unit, an important nursing measure is to prevent the
loss of muscle mass. What is the term used for loss of muscle mass and how can the patient prevent it?
133)
Aaron arrived at the hospital with the following symptoms: drooping eyelids; fatigue and weakness of his
muscles; and difficulty talking, breathing, and swallowing. What was his diagnosis?
134)
Gary was injured in an automobile accident that severed the motor neurons innervating his quadriceps. Even
though he has had extensive physical therapy, he is still suffering muscle atrophy. Why is the therapy not
working?
Answer Key
1)
C
2)
B
3)
C
4)
D
5)
C
6)
B
7)
B
8)
B
9)
A
10)
D
11)
D
12)
A
13)
B
14)
A
15)
A
16)
B
17)
B
18)
C
19)
D
20)
D
21)
D
22)
A
23)
B
24)
A
25)
D
26)
A
27)
A
28)
A
29)
D
30)
C
31)
D
32)
B
33)
B
34)
D
35)
B
36)
A
37)
B
38)
B
39)
A
40)
A
41)
B
42)
B
43)
A
44)
B
45)
D
46)
D
47)
C
48)
A
49)
A
50)
D
28
51)
D
52)
B
53)
It is an inability of the muscle to contract despite continued stimulation.
54)
Folds on the surface of smooth muscle cells that correspond to T tubules in skeletal muscle cells.
55)
acetylcholinesterase
56)
B
57)
The ultimate switch is the enzyme acetylcholinesterase. When the neuron stops releasing ACh, the muscle would not
58)
E
59)
D
60)
contraction
61)
Muscle tension is the force exerted by a contracting muscle on an object.
62)
The parts of the muscle triad are two adjacent SR terminal cisterns plus one intervening T tubule. The sarcoplasmic
63)
insertion
64)
A
65)
tetanus
66)
C
67)
C
68)
E
69)
skeletal
70)
1. The first 4-6 seconds of energy come from stored ATP in the muscle cell.
71)
D
72)
Norepinephrine's effects depend upon the action of the receptor to which it binds.There is a different type of NE
73)
All three muscle types initially respond by contracting more forcefully, then relaxing. However, smooth muscle
74)
Red muscles tend to have a slow (oxidative) rate and fatigue resistance, whereas white muscle cells have a fast
75)
Following the death of an individual, ATP is rapidly consumed and cannot be replaced. Because cross bridge
76)
satellite cells
77)
A
78)
It is a sudden, involuntary twitch in smooth or skeletal muscle, possibly due to chemical imbalances.
79)
Skeletal muscle cells require a lot of rapidly available fuel to burn in order to function properly. They also require a lot
80)
cardiac
81)
B
Answer Key
102)
B
103)
A
104)
C
105)
A
106)
B
107)
A
108)
A
109)
A
110)
A
111)
A
112)
A
113)
A
114)
B
115)
A
116)
A
117)
A
118)
A
119)
A
120)
A
121)
A
122)
B
123)
B
124)
B
125)
A
126)
A
127)
Two things have occurred to Lauren while she was convalescing from her injury. First, the immobilization of the arm
Answer Key
128)
This is due to sustained spasm, or tetanic contraction, of the gastrocnemius muscle. The causes could be low blood
129)
Peristalsis is wavelike movement produced by the circular and longitudinal muscle fibers of the intestinal walls that
130)
These activities are isotonic exercises in which muscle tension is constant and then shortens to produce muscle
131)
depolarization occurs, resulting in an influx of calcium ions from the extracellular fluid into the terminals, which then
132)
Disuse atrophy is degeneration and loss of muscle mass. The size, shape, tone, and strength of muscles (including the
133)
Aaron probably has myasthenia gravis (an autoimmune disease), which involves a shortage of ACh receptors at the
134)
In denervation atrophy, fibrous connective tissue replaces the muscle tissue that was lost. When atrophy is complete,