Chapter 9 Muscles and Muscle Tissue Flashcards
(303 cards)
1
Q
An entire skeletal muscle is surrounded by __________.
A) perimysium
B) sarcolemma
C) epimysium
D) tendon sheath
E) endomysium
A
C) epimysium
2
Q
A motor neuron along with all the muscle fibers it supplies is called a(n) __________.
A) synaptic cleft
B) motor unit
C) motor end plate
D) neuromuscular junction
E) axon terminal
A
- motor unit
3
Q
Which of the following does NOT occur during skeletal muscle contraction?
A) Myosin heads bind to actin.
B) The I bands shorten, and H zones disappear.
C) Calcium binds to myosin heads.
D) Calcium concentration in the sarcoplasm increases.
E) ATP is hydrolyzed.
A
C) Calcium binds to myosin heads.
4
Q
What is the ion released from the terminal cisternae that combines with troponin and removes the blocking action of tropomyosin, resulting in the formation of cross bridges?
- Na+
- Cl-
- K+
- H+
- Ca2+
A
- Ca2+
5
Q
Each skeletal muscle fiber is controlled by a neuron at a single __________.
- neuromuscular junction
- sarcomere
- transverse tubule
- synaptic knob
- varicosity
A
- neuromuscular junction
6
Q
Which of the following best describes the composition of the structure known as a triad in a skeletal muscle fiber?
- terminal cisterna, transverse tubule, and terminal cisterna
- ATP, CP, and glycogen
- actin, troponin, and tropomyosin
- sarcolemma, sarcoplasm, and sarcoplasmic reticulum
- A band, I band, and H band
A
- terminal cisterna, transverse tubule, and terminal cisterna
7
Q
In the sliding filament model of muscle contraction, the myofilaments slide over each other, resulting in the overlapping of actin and __________.
- tropomyosin
- myosin
- troponin
- actin
- thin filaments
A
- myosin
8
Q
Myoglobin __________.
- is a byproduct of glycolysis
- is a sugar-storage molecule
- activates myosin kinase in smooth muscle contraction
- is released into the sarcoplasm by the sarcoplasmic reticulum
- is an oxygen-storage molecule
A
- is an oxygen-storage molecule
9
Q
The functional unit of contraction in a skeletal muscle fiber is the __________.
A) myofilament
B) sarcoplasmic reticulum
C) myofibril
D) sarcomere
E) sarcolemma
A
D) sarcomere
10
Q
The space between the axon terminus of the neuron and the sarcolemma of the muscle fiber is the __________.
- synaptic knob
- M line
- synaptic cleft
- motor unit
- motor end plate
A
- synaptic cleft
11
Q
Continued mild or partial contraction of a muscle that keeps it healthy and ready to respond is known as muscle __________.
- twitch
- stimulation
- tone
- tetanus
- summation
A
- tone
12
Q
The type of muscle contraction in which the muscle fibers produce increased tension although the muscle neither shortens nor lengthens is called __________.
- isometric
- tetany
- treppe
- isotonic
- concentric
A
- isometric
13
Q
Which of the following statements about smooth muscle is true?
- Contractions are rapid and forceful.
- Fibers are small and spindle-shaped.
- It has branching fibers.
- Nuclei are peripherally located in the fibers.
- Smooth muscle is striated and involuntary.
A
- Fibers are small and spindle-shaped.
14
Q
Which of the following statements is INCORRECT?
- Smooth muscles form valves regulating the passage of substances through internal openings of the digestive and urinary tracts.
- The contractions of skeletal muscles pull on tendons and move elements of the skeleton.
- Skeletal muscle contractions help maintain body temperature.
- Skeletal muscles are responsible for the pumping action of the heart.
- Skeletal muscles support the weight of some internal organs.
A
- Skeletal muscles are responsible for the pumping action of the heart.
15
Q
Which of the following substances increases in quantity during repetitive muscle contraction during oxygen deficit?
- oxygen
- creatine phosphate
- lactic acid
- adenosine triphosphate (ATP)
- glucose
A
- lactic acid
16
Q
The sequence of electrical changes that occurs along the sarcolemma when a muscle fiber is stimulated is known as the __________.
A) receptor potential
B) action potential
C) generator potential
D) motor end plate potential
E) resting membrane potential
A
B) action potential
17
Q
Which of the following allows recoil of the muscle fiber when contraction ends?
- troponin
- actin
- myosin
- tropomyosin
- elastic filaments
A
- elastic filaments
18
Q
Which one of the following binds calcium ions in a smooth muscle, causing contraction?
- myosin
- troponin
- tropomyosin
- actin
- calmodulin
A
- calmodulin
19
Q
All of the following terms refer to the ability to receive and respond to a stimulus EXCEPT __________.
- irritability
- excitability
- contractility
- responsiveness
A
- contractility
20
Q
During the phase of excitation-contraction coupling of skeletal muscle, what occurs immediately after the action potential spreads down the T tubule?
- The cross bridge forms.
- The power stroke takes place.
- Acetylcholine is released from the axon terminus.
- The sarcoplasmic reticulum releases calcium.
A
4. The sarcoplasmic reticulum releases calcium.
21
Q
Which of the following muscles is voluntary?
- the muscle of the stomach
- the muscle in the wall of the heart
- the muscle in the wall of the urinary bladder
- the muscle that extends the arm at the elbow
A
- the muscle that extends the arm at the elbow
22
Q
Which of the following is NOT a characteristic of skeletal muscle contraction?
- It can perform both anaerobic and aerobic metabolism.
- It contracts rapidly.
- It can exert tremendous power.
- It can contract for long periods of time without tiring.
A
- It can contract for long periods of time without tiring.
23
Q
Which type of skeletal muscle contains abundant quantities of glycogen?
- fast glycolytic fibers
- slow oxidative fibers
- slow glycolytic fibers
- fast oxidative fibers
A
- fast glycolytic fibers
24
Q
Myofilament cross bridges form when which two structures bond?
- myosin tails and myosin heads
- troponin and tropomyosin
- globular actin and troponin
- myosin heads and globular actin
A
- myosin heads and globular actin
25
Which of the following is thought to be an autoimmune disease of acetylcholine receptors?
1. muscular dystrophy
2. myotonic dystrophy
3. fibromyalgia
4. myasthenia gravis
4. myasthenia gravis
26
The refractory period in which the muscle will NOT contract if stimulated occurs during __________ of the muscle cell.
1. hyperpolarization
2. repolarization
3. depolarization
4. polarization
2. repolarization
27
What is the cause of rigor mortis?
A) high levels of sodium in the cell after death
B) calcium influx into the sarcoplasm after death
C) breakdown of protein in the cell after death
D) diffusion of potassium out of the cell after death
B) calcium influx into the sarcoplasm after death
28
Where does 95% of the energy needed for contraction come from during moderate exercise?
1. creatine phosphate
2. aerobic respiration
3. anaerobic glycolysis
4. lactic acid
2. aerobic respiration
29
The alternating contraction and relaxation of opposing layers of smooth muscle is referred to as \_\_\_\_\_\_\_\_\_\_.
1. isometric contraction
2. automatic contraction
3. isotonic contraction
4. peristalsis
4. peristalsis
30
Which of the following characteristics is unique to smooth muscle?
1. the absence of striations
2. presence of gap junctions
3. the ability of ATP to energize the sliding process
4. presence of sarcoplasmic reticulum
1. the absence of striations
31
A Bands are made of
A. myosin filaments only
B. actin filaments and Z discs
C. actin filaments only
D. myosin filaments and actin filaments
E. myosin filaments and Z discs
D. myosin filaments and actin filaments
32
What is the connective tissue surrounding an entire **muscle cell** called?
A. endomysium
B. perimysium
C. tendon
D. sarcolemma
E. epimysium
B. perimysium
33
The ___ ions released from the sarcoplasmic reticulum binds to sites on ________ causing a shift in that complex to expose myosin binding sites on the actin filaments.
A. Ca+2 ; troponin
B. Na+ ; tropomyosin
C. K+ ; troponin
D. Ca+2 ; tropomyosin
E. Ca+2 ; connectin
A. Ca+2 ; troponin
34
The H zone gets larger when a muscle is \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
A. contracted
B. resting
C. stretched
C. stretched
35
This enzyme allows for the conversion of two molecules of ADP to produce one molecule of ATP and one molecule of AMP for short term energy needs.
A. ATP synthase
B. creatine phosphatase
C. myokinase
D. ATPase
E. phosphagenase
C. myokinase
36
These structures are where smooth muscle intermediate filaments interact with sarcoplasm:
A. dense plaques
B. intermediate filament
C. T- tubules
D. dense bodies
E. myosin filament
D. dense bodies
37
Because of structure differences, smooth muscle is _______ to fatigue because it requires ______ ATP than skeletal muscle for contraction.
A. quicker; more
B. quicker; less
C. slower; more
D. slower; less
D. slower; less
38
Cardiac muscle cells are different from skeletal muscle cells in that they are \_\_\_\_\_\_, and contain ______ nuclei.
A. smooth; many
B. branched; 2
C. striated; 1
D. smooth; 2
E. branched; 1
B. branched; 2
39
**Which mechanism provides ATP for short-term (5-10 sec) muscle contraction?**
**A. phosphagen system**
**B. aerobic respiration**
**C. anaerobic respiration**
**D. any of these**
**A. phosphagen system**
40
1) The I band within a skeletal muscle fiber is indicated by \_\_\_\_\_\_\_\_.
A) Label A
B) Label B
C) Label C
D) Label D
B) Label B
41
2) The A band within a skeletal muscle fiber is indicated by \_\_\_\_\_\_\_\_.
A) Label A
B) Label B
C) Label C
D) Label D
A) Label A
42
3) The H zone, located within the A band, lacks thin filaments and is represented by \_\_\_\_\_\_\_\_.
A) Label A
B) Label B
C) Label C
D) Label D
D) Label D
43
4) The myofilament composed of actin is indicated by \_\_\_\_\_\_\_\_.
A) Label A
B) Label B
C) Label C
D) Label D
C) Label C
44
5) The epimysium is represented by \_\_\_\_\_\_\_\_.
A) Label A
B) Label B
C) Label C
D) Label D
A) Label A
45
6) The perimysium wraps a fascicle of muscle cells and is represented by \_\_\_\_\_\_\_\_.
A) Label A
B) Label B
C) Label C
D) Label D
C) Label C
46
7) The muscle fiber (cell) is indicated by \_\_\_\_\_\_\_\_.
A) Label A
B) Label B
C) Label C
D) Label D
D) Label D
47
8) The endomysium that wraps individual muscle fibers is indicated by \_\_\_\_\_\_\_\_.
A) Label A
B) Label B
C) Label C
D) Label D
B) Label B
48
9) Striated involuntary muscle tissue is classified as ________ muscle.
A) skeletal
B) cardiac
C) smooth
D) either smooth or skeletal
B) cardiac
49
10) The epimysium covering on the outside of the muscle can blend into cordlike ________ or sheetlike \_\_\_\_\_\_\_\_.
A) tendons; aponeuroses
B) ligaments; tendons
C) fascia; ligaments
D) aponeuroses; ligaments
A) tendons; aponeuroses
50
**The ________ is an organelle that wraps and surrounds the myofibril and stores calcium.**
**A) cross bridge**
**B) sarcomere**
**C) sarcolemma**
**D) sarcoplasmic reticulum**
**D) sarcoplasmic reticulum**
51
12) Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as \_\_\_\_\_\_\_\_.
A) elasticity
B) irritability
C) contractility
D) extensibility
C) contractility
52
13) One neuron and all the skeletal muscles it stimulates is known as a \_\_\_\_\_\_\_\_.
A) sarcoplasmic reticulum
B) motor unit
C) synaptic cleft
D) neuromuscular junction
B) motor unit
53
**The heads of the myosin myofilaments are called ________ when they link the thick and thin filaments together during skeletal muscle contraction.**
**A) neuromuscular junctions**
**B) synapses**
**C) cross bridges**
**D) motor units**
**C) cross bridges**
54
15) The gap between the motor neuron and the muscle fiber it supplies at the neuromuscular junction is called the \_\_\_\_\_\_\_\_.
A) synaptic cleft
B) motor unit
C) cross bridge
D) H zone
A) synaptic cleft
55
16) When a skeletal muscle is fully contracted, the ________ are closer to the thick filaments.
A) Z discs
B) M lines
C) cross bridges
D) A bands
A) Z discs
56
17) Anaerobic glycolysis requires ________ to make ATP.
A) creatine phosphate
B) oxygen
C) glucose
D) both oxygen and glucose
B) oxygen
57
18) A smooth, sustained contraction is called \_\_\_\_\_\_\_\_.
A) fused, or complete, tetanus
B) a twitch
C) unfused, or incomplete, tetanus
D) summing of contractions
A) fused, or complete, tetanus
58
19) Contractions in which muscles shorten and produce movement are known as \_\_\_\_\_\_\_\_.
A) isotonic contractions
B) twitches
C) isometric contractions
D) resistance exercises
C) isometric contractions
59
20) The point of muscle attachment to an immovable or less movable bone is known as the \_\_\_\_\_\_\_\_.
A) innervation
B) action
C) insertion
D) origin
D) origin
60
21) Muscles that perform opposite actions to one another are termed \_\_\_\_\_\_\_\_.
A) synergists
B) prime movers
C) antagonists
D) fixators
C) antagonists
61
22) The arrangement of fascicles in orbicularis oris is \_\_\_\_\_\_\_\_.
A) circular
B) convergent
C) pennate
D) fusiform
A) circular
62
23) The muscle that closes each eye is the \_\_\_\_\_\_\_\_.
A) orbicularis oris
B) frontalis
C) orbicularis oculi
D) zygomaticus
C) orbicularis oculi
63
24) The prime mover of arm abduction is the ________ muscle.
A) trapezius
B) deltoid
C) latissimus dorsi
D) quadratus lumborum
B) deltoid
64
25) The hamstring group is the prime mover of thigh ________ and knee \_\_\_\_\_\_\_\_.
A) extension; flexion
B) dorsiflexion; plantar flexion
C) abduction; adduction
D) rotation; circumduction
A) extension; flexion
65
26) An inherited disease that causes muscles to degenerate and atrophy is known as \_\_\_\_\_\_\_\_.
A) torticollis
B) muscular dystrophy
C) cystic fibrosis
D) myasthenia gravis
B) muscular dystrophy
66
1) Striated involuntary muscle tissue found in the heart is \_\_\_\_\_\_\_\_.
A) smooth muscle
B) skeletal muscle
C) dense regular
D) cardiac muscle
E) dense irregular
D) cardiac muscle
67
2) Endomysium covers \_\_\_\_\_\_\_\_.
A) fascicles of muscle cells
B) an entire muscle
C) an individual muscle cell
D) myofibrils
E) smooth muscle only
C) an individual muscle cell
68
The type of muscle tissue pictured in Figure 6.3 is \_\_\_\_\_\_\_\_.
A) skeletal muscle
B) voluntary
C) striated
D) found only in the heart
E) smooth muscle
E) smooth muscle
69
4) The plasma membrane of a skeletal muscle cell is called the \_\_\_\_\_\_\_\_.
A) sarcolemma
B) sarcomere
C) myofilament
D) sarcoplasm
E) sarcoplasmic reticulum
A) sarcolemma
70
5) Smooth muscle cells are \_\_\_\_\_\_\_\_.
A) multinucleate
B) involuntary
C) branched
D) striated
E) cylindrical
B) involuntary
71
6) Which type of muscle tissue contracts most quickly upon stimulation?
A) skeletal
B) visceral
C) cardiac
D) smooth
E) tendons
A) skeletal
72
7) Which of the following is NOT a function of the muscular system?
A) production of movement
B) maintenance of posture
C) stabilization of joints
D) generation of heat
E) hematopoiesis
E) hematopoiesis
73
**A sarcomere is \_\_\_\_\_\_\_\_.**
**A) the nonfunctional unit of skeletal muscle**
**B) the contractile unit between two Z discs**
**C) the area between two intercalated discs**
**D) the wavy lines on the cell, as seen in a microscope**
**E) a compartment in a myofilament**
**B) the contractile unit between two Z discs**
74
9) Which one of the following is composed of myosin protein?
A) thick filaments
B) thin filaments
C) all myofilaments
D) Z discs
E) light bands
A) thick filaments
75
10) Cross bridges are created when myosin heads bind to \_\_\_\_\_\_\_\_.
A) thick filaments
B) sarcomeres
C) thin filaments
D) sarcoplasmic reticula
E) myosin filaments
C) thin filaments
76
11) A motor neuron and all of the skeletal muscle fibers it stimulates are termed a \_\_\_\_\_\_\_\_.
A) myofilament
B) synaptic cleft
C) motor unit
D) neuromuscular junction
E) neurotransmitter
C) motor unit
77
12) Why are calcium ions necessary for skeletal muscle contraction?
A) calcium increases the action potential transmitted along the sarcolemma
B) calcium releases the inhibition on Z discs
C) calcium triggers the binding of myosin to actin
D) calcium causes ATP binding to actin
E) calcium binds to regulatory proteins on the myosin filaments, changing both their shape and their position on the thick filaments
C) calcium triggers the binding of myosin to actin
78
13) The mechanical force of contraction is generated by \_\_\_\_\_\_\_\_.
A) shortening of the thick filaments
B) shortening of the thin filaments
C) a sliding of thin filaments past thick filaments
D) the "accordian-like" folding of thin and thick filaments
E) the temporary disappearance of thin filaments
C) a sliding of thin filaments past thick filaments
79
14) Acetylcholine is \_\_\_\_\_\_\_\_.
A) an ion pump on the postsynaptic membrane
B) a source of energy for muscle contraction
C) a component of thick myofilaments
D) an oxygen-binding protein
E) a neurotransmitter that stimulates skeletal muscle
E) a neurotransmitter that stimulates skeletal muscle
80
15) The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell is called the \_\_\_\_\_\_\_\_.
A) motor unit
B) sarcomere
C) neuromuscular junction
D) synaptic cleft
E) cross bridge
D) synaptic cleft
81
16) Neurotransmitters are released upon stimulation from a nerve impulse by the \_\_\_\_\_\_\_\_.
A) myofibrils
B) sarcoplasmic reticulum
C) thick filaments
D) axon terminals of the motor neuron
E) sarcolemma of the muscle cell
D) axon terminals of the motor neuron
82
17) An elaborate and specialized network of membranes in skeletal muscle cells that function in calcium storage is the \_\_\_\_\_\_\_\_.
A) sarcolemma
B) mitochondria
C) intermediate filament network
D) myofibrillar network
E) sarcoplasmic reticulum
E) sarcoplasmic reticulum
83
18) During skeletal muscle contraction, myosin heads attach to binding sites associated with \_\_\_\_\_\_\_\_.
A) myosin filaments
B) actin filaments
C) Z discs
D) thick filaments
E) the H zone
B) actin filaments
84
**Which of the following can actually shorten during a muscle contraction?**
**A) myosin filament**
**B) A band**
**C) actin filament**
**D) sarcomere**
**E) myofilament**
**D) sarcomere**
85
20) In order to excite a muscle cell, acetycholine must \_\_\_\_\_\_\_\_.
A) enter the muscle cell by endocytosis
B) travel into the axon terminal of the nerve cell by endocytosis
C) enter the muscle cell through protein channels
D) bind to receptors in the sarcolemma of the muscle cell
E) break down acetylcholinesterase in the synaptic cleft
D) bind to receptors in the sarcolemma of the muscle cell
86
21) Which of these events must occur first to trigger the skeletal muscle to generate an action potential and contract?
A) sodium ions rush into the cell
B) acetylcholine (ACh) causes temporary permeability to sodium
C) diffusion of potassium ions out of the cell
D) operation of the sodium-potassium pump
E) acetylcholinesterase (AchE) breaks down acetylcholine (ACh)
B) acetylcholine (ACh) causes temporary permeability to sodium
87
22) A skeletal muscle twitch differs from a tetanic contraction in that \_\_\_\_\_\_\_\_.
A) the tetanic contraction is considered abnormal, while the twitch is a normal muscle response
B) the tetanic contraction is caused by a single stimulus, while the twitch is caused by very rapid multiple stimuli
C) the muscle twitch is prolonged and continuous while a tetanic contraction is brief and "jerky"
D) the muscle twitch occurs only in small muscles while a tetanic contraction occurs in large muscle groups
E) the muscle twitch is a brief and "jerky" movement, while the tetanic contraction is prolonged and continuous
E) the muscle twitch is a brief and "jerky" movement, while the tetanic contraction is prolonged and continuous
88
23) Creatine phosphate (CP) functions within the muscle cells by \_\_\_\_\_\_\_\_.
A) forming a temporary chemical compound with myosin
B) forming a chemical compound with actin
C) inducing a conformational change in the myofilaments
D) storing energy that will be transferred to ADP to resynthesize ATP as needed
E) storing energy that will be transferred to ATP to resynthesize ADP as needed
D) storing energy that will be transferred to ADP to resynthesize ATP as needed
89
24) The condition of skeletal muscle fatigue can be best explained by \_\_\_\_\_\_\_\_.
A) the all-or-none law
B) the inability to generate sufficient quantities of ATP due to feedback regulation of synthesis
C) insufficient intracellular quantities of ATP due to excessive consumption
D) a total lack of ATP
E) inadequate numbers of mitochondria
C) insufficient intracellular quantities of ATP due to excessive consumption
90
25) Which of the following is an example of an isometric contraction?
A) shaking the head as to say "no"
B) pushing against an immovable wall
C) bending the elbow
D) rotating the arm
E) nodding the head as to say "yes"
B) pushing against an immovable wall
91
26) Anaerobic glycolysis occurs without \_\_\_\_\_\_\_\_.
A) ATP
B) oxygen
C) lactic acid
D) carbon dioxide
E) glucose
B) oxygen
92
27) The least movable point of muscle attachment to a bone is termed its \_\_\_\_\_\_\_\_.
A) bone marking
B) function
C) insertion
D) action
E) origin
E) origin
93
28) The movement opposite to abduction is \_\_\_\_\_\_\_\_.
A) flexion
B) rotation
C) circumduction
D) adduction
E) supination
D) adduction
94
29) Which of the following muscles closes the jaw?
A) buccinator
B) zygomaticus
C) frontalis
D) sternocleidomastoid
E) both masseter and temporalis
E) both masseter and temporalis
95
30) Sandra is playing the piano for her recital. Which muscle is NOT involved in the movement of her hands and/or fingers \_\_\_\_\_\_\_\_.
A) flexor carpi radialis
B) flexor carpi ulnaris
C) extensor digitorum
D) extensor digitorum longus
E) extensor carpi radialis
D) extensor digitorum longus
96
31) Which of these muscles is a synergist to masseter?
A) sternocleidomastoid
B) temporalis
C) trapezius
D) buccinator
E) orbicularis oris
B) temporalis
97
32) Which muscle helps compress the abdominal contents during defecation or childbirth?
A) internal intercostals
B) deltoids
C) trapezius
D) iliopsoas
E) rectus abdominis
E) rectus abdominis
98
33) A muscle located on the ventral (anterior) side of the body is the \_\_\_\_\_\_\_\_.
A) pectoralis major
B) occipitalis
C) gastrocnemius
D) gluteus medius
E) latissimus dorsi
A) pectoralis major
99
34) A nursing infant develops a powerful sucking muscle that adults also use for whistling or blowing a trumpet called the \_\_\_\_\_\_\_\_.
A) platysma
B) masseter
C) zygomaticus
D) buccinator
E) temporalis
D) buccinator
100
35) What is the main function of the quadriceps group?
A) arm flexion
B) hand supination
C) thigh abduction
D) knee extension
E) foot inversion
D) knee extension
101
36) A muscle group that works with and assists the action of a prime mover is a(n) \_\_\_\_\_\_\_\_.
A) antagonist only
B) fixator only
C) synergist only
D) antagonist and synergist
E) antagonist and fixator
C) synergist only
102
37) Which muscle is an antagonist to gastrocnemius?
A) sartorius
B) tibialis anterior
C) fibularis brevis
D) fibularis longus
E) soleus
B) tibialis anterior
103
38) Which muscle group includes the biceps femoris, semimembranosus, and semitendinosus?
A) abdominal muscles
B) quadriceps group
C) adductor group
D) fibularis muscles
E) hamstring group
E) hamstring group
104
39) Paralysis of which of the following would make an individual unable to flex the hip \_\_\_\_\_\_\_\_.
A) biceps femoris
B) gastrocnemius
C) tibialis anterior
D) soleus
E) iliopsoas
E) iliopsoas
105
40) Which one of the following muscles is involved in abduction of the arm at the shoulder joint?
A) deltoid
B) biceps brachii
C) triceps brachii
D) latissimus dorsi
E) pectoralis major
A) deltoid
106
41) What is the origin of the deltoid muscle?
A) proximal radius
B) proximal humerus
C) distal humerus
D) olecranon process of ulna
E) scapular spine and clavicle
E) scapular spine and clavicle
107
42) While doing "jumping jacks" during an exercise class, your arms and legs move laterally away from the midline of your body. This motion is called \_\_\_\_\_\_\_\_.
A) extension
B) flexion
C) abduction
D) adduction
E) circumduction
C) abduction
108
43) Which of the following muscles are antagonists?
A) biceps brachii and triceps brachii
B) bicpes femoris and biceps brachii
C) vastus medialis and vastus lateralis
D) masseter and temporalis
E) gastrocnemius and soleus
A) biceps brachii and triceps brachii
109
44) What condition results if muscles are not used, such as when immobilized in a cast for healing a broken bone?
A) hypertrophy
B) lordosis
C) atrophy
D) spina bifida
E) scoliosis
C) atrophy
110
45) Which one of the following is NOT a criterion generally used in naming muscles?
A) relative size of the muscle
B) number of origins of the muscle
C) shape of the muscle
D) method of attachment of the muscle to bone
E) action of the muscle
D) method of attachment of the muscle to bone
111
1) Cardiac and skeletal muscle both possess striations. True/False Questions
TRUE
112
2) All types of muscle have endomysium covering individual muscle cells. True/False Questions
TRUE
113
3) Bundles of muscle fibers are known as aponeuroses. True/False Questions
FALSE
114
4) The striations seen in skeletal muscle are actually alternating dark A and light I bands. True/False Questions
TRUE
115
5) The sarcoplasmic reticulum wraps like a sleeve around the myofibril and stores and releases calcium.True/False Questions
TRUE
116
6) A neuromuscular junction consists of one neuron and all the skeletal muscles it stimulates. True/False Questions
FALSE
117
7) The neurotransmitter used by the nervous system to activate skeletal muscle cells is acetylcholine. True/False Questions
TRUE
118
8) Thick filaments are made of a protein called actin. True/False Questions
FALSE
119
9) Aerobic respiration requires the use of oxygen to generate ATP. True/False Questions
TRUE
120
10) The fastest mechanism for producing ATP is aerobic respiration. True/False Questions
FALSE
121
11) Isometric contractions produce movement when filaments slide past one another and the muscle shortens. True/False
FALSE
122
12) Aerobic, or endurance, exercise involves jogging or biking. True/False
TRUE
123
13) A muscle twitch results when the muscle is stimulated so rapidly that no evidence of relaxation is seen. True/False
FALSE
124
14) The effect of the neurotransmitter on the muscle cell membrane is to temporarily modify its permeability of ions such as Na+ and K+. True/False
TRUE
125
15) When a muscle fiber contracts, the I bands diminish in size, the H zones disappear, and the A bands move closer together but do not diminish in length. True/False
TRUE
126
16) Abduction and adduction are antagonistic actions. True/False
TRUE
127
17) The deltoid is a prime mover of arm adduction. True/False
FALSE
128
18) The deepest muscle of the abdominal wall is the transversus abdominis. True/False
TRUE
129
19) The deltoid muscle is a common site for intramuscular injections. True/False
TRUE
130
20) Plantar flexion at the ankle joint is accomplished by the tibialis anterior muscle. True/False
FALSE
131
21) The hamstring group inserts into the distal tibia. True/False
FALSE
132
22) Muscle development in babies occurs in a cephalic/caudal direction. True/False
TRUE
133
23) Supination and pronation refer to up and down movements of the foot at the ankle. True/False
FALSE
134
1) Voluntary muscle tissue
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
B) skeletal muscle tissue
135
2) Muscle tissue found only in the heart
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
C) cardiac muscle tissue
136
3) Muscle tissue that forms valves to regulate the passage of substances through internal body openings
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
A) smooth muscle tissue
137
4) Muscle tissue that is multinucleate
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
B) skeletal muscle tissue
138
5) Muscle tissue composed of branching cells and intercalated discs
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
C) cardiac muscle tissue
139
6) Muscle tissue that activates arrector pili muscles to stand hairs on end
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
A) smooth muscle tissue
140
7) Performs very slow, sometimes rhythmic, contractions
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
A) smooth muscle tissue
141
8) Muscle tissue that maintains posture, body position, and stabilizes joints
A) smooth muscle tissue
B) skeletal muscle tissue
C) cardiac muscle tissue
B) skeletal muscle tissue
142
9) The sarcoplasmic reticulum stores this chemical
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
A) calcium ions
143
10) Specific neurotransmitter that stimulates skeletal muscle cells
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
B) acetylcholine
144
11) Chemical that enters a muscle cell upon excitation
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
D) sodium ions
145
12) Gap between the axon terminals and the plasma membrane of a neighboring muscle cell
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
C) synaptic cleft
146
13) Electrical current that travels the length of the muscle
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
F) action potential
147
14) Enzyme that breaks down acetylcholine (ACh)
A) calcium ions
B) acetylcholine
C) synaptic cleft
D) sodium ions
E) acetylcholinesterase
F) action potential
E) acetylcholinesterase
148
Muscle Tissue Type: \_\_\_\_\_\_\_\_\_\_\_\_
* Long, cylindrical, ________ cells with obvious striations
* _______ and controls voluntary muscles movement
Skeletal; multinucleate; Initiates
149
Muscle Tissue Type: \_\_\_\_\_\_\_
* Branching, \_\_\_\_\_\_, single nucleate cells connected at intercalated discs
* Found in the _____ of the heart
* Under involuntary control
Cardiac; striated; walls
150
Muscle Tissue Type: \_\_\_\_\_\_
* Sheets of spindle-shaped cells with single nuclei that have no \_\_\_\_\_\_
* Found in the walls of \_\_\_\_\_\_, some ducts and hollow organs
* Under involuntary control
Smooth; striations; blood vessels
151
Which of the following muscular functions serves a metabolic function?
A) Movement
B) Posture maintenance
C) Joint stabilization
D) Heat generation
D) Heat generation
152
Which of the following pairs is not correct?
A) Skeletal muscle : striated
B) Cardiac muscle : voluntary
C) Cardiac muscle : striated
D) Smooth muscle : involuntary
B) Cardiac muscle : voluntary
153
Of the following muscle types, which is the only one subject to conscious control?
A) Smooth
B) Skeletal
C) Cardiac
D) All of these muscle types are subject to conscious control.
B) Skeletal
154
Which of the following is not a functional characteristic of muscle tissue?
A) Excitability/irritability
B) Contractility
C) Extensibility
D) Elasticity
E) All are functional characteristics of muscle tissue
E) All are functional characteristics of muscle tissue
155
Elasticity is the ability to shorten in length when stimulated. True/False
FALSE, Contractility
156
Extensibility is the bility to be stretched or extended beyond their resting length without rupturing. True/False
True
157
Myofibril are thin muscle structures. True/False
TRUE
158
Each muscle is a discrete organ composed of hundreds to thousands of muscle fibers, blood vessels, nerve fibers, and connective tissue. True/False
TRUE
159
Which of the following is not true of Skeletal Muscle Tissue?
A) Has a rich blood supply due to its high metabolic demands
B) Contains obvious bands/striations under the microscope
C) Under Both voluntary and involuntary control.
D) Under voluntarily control
E) Contracts rapidly but tires easily
C) Under Both voluntary and involuntary control.
160
Each muscle is divided into smaller sections called muscle fiber. True/False
FALSE, they are call fasicles
161
What is it called?
Endomysium
| (between individual muscle fibers)
162
What is it?
Fascicle
| (Wrapped by perimysium)
163
The epimysium may be ________ fused to the periosteum or the perichondrium of cartilage.
A) directly
B) indirectly
A) directly
164
The epimysium may attach ________ via tendons that extend beyond the muscle, or as broad, sheet-like aponeuroses.
A) directly
B) indirectly
B) indirectly
165
Indirect attachments are more common than the direct attachment. True/False
TRUE
166
Most skeletal muscles span joints and are attached to bone in at least _______ places.
two
167
One end is relatively immobile, while the other end moves the bone. The Origin is the movable end of the skeletal muscle. True/False
FALSE, the movable end is the insertion
168
Which of the following is not a prefix used to refer to muscle?
A) Mys
B) Myo
C) Sarco
D) Lemma
D) Lemma
169
The elastic components of muscle consist of which elements?
A) Tendon, epimysium, muscle fiber
B) Bone, perimysium, blood vessel
C) Fascicle, bone, blood vessel
D) Tendon, epimysium, perimysium, endomysium
D) Tendon, epimysium, perimysium, endomysium
170
Sarcoplasm contains a unique oxygen-binding protein called _______ .
myoglobin
171
Myoglobin is a protein found in the muscle tissue of vertebrates in general and in almost all mammals. True/False
TRUE
172
Hemoglobin is the primary oxygen-carrying pigment of muscle tissues. True/False
FALSE, myoglobin is the primary oxygen-carrying pigment of muscle tissues.
173
Myofibrils are densely packed, rod-like contractile elements within a muscle fiber. True/Flase
TRUE
174
The myofibrils within a fiber are aligned into a repeating series of striations or stripes called Sarcolemma. True/False
FALSE, they are called sarcomeres
175
**What is the functional, contractile unit of a muscle?**
**A) myosin**
**B) sarcomere**
**C) bactin**
**D) myofibril**
**B) sarcomere**
176
Actin and myosin are the primary proteins responsible for muscle contraction. True/False
TRUE
177
Proteins (connections) that anchor the thin actin filaments.
A) I(light) band
B) H zone
C) M line
D) Z-disc
E) A(dark) band
D) Z-disc
178
Extends to the right and left of a Z disk and includes the non-overlapping parts of the thin filaments
A) I(light) band
B) H zone
C) M line
D) Z-disc
E) A(dark) band
A) I(light) band
179
Extends the length of the thick myosin filament
A) I(light) band
B) H zone
C) M line
D) Z-disc
E) A(dark) band
E) A(dark) band
180
In the center of the A band, includes the portion of the thick filament NOT overlapping with the thin filament
A) I(light) band
B) H zone
C) M line
D) Z-disc
E) A(dark) band
B) H zone
181
Middle of H zone that contains delicate fibers holding the thick filaments in place
A) I(light) band
B) H zone
C) M line
D) Z-disc
E) A(dark) band
C) M line
182
In the relaxed state, thin (actin) and thick myosin) filaments overlap \_\_\_\_\_.
A) completely
B) slightly
B) slightly
183
By the end of contraction, actin and myosin filaments overlap \_\_\_\_\_\_.
A) completely
B) slightly
A) completely
184
§Thick filaments are composed of the protein \_\_\_\_\_, held together by the protein\_\_\_\_.
Myosin; Titin
185
Which of the following components accounts for the bulk of muscle fiber volume?
A) Glycosomes
B) Mitochondria
C) Myofibrils
D) Sarcoplasm
C) Myofibrils
186
The functional unit of a skeletal muscle is:
A) sarcomere
B) A band
C) myofibril
D) sarcolemma
A) sarcomere
187
A sheetlike extension of the epimysium is called a(n) \_\_\_\_\_\_
A) aponeurosis
B) fascicle
C) sarcoplasmic reticulum
D) tendon
A) aponeurosis
188
**Thick filaments are found in the _______ of the sarcomere.**
**A) Z disc**
**B) I band**
**C) A band**
**D) All of the above contain thick filaments.**
**C) A band**
189
The thin filaments are not comprised of which of the following components?
A) Actin
B) Titin
C) Troponin
D) Tropomyosin
B) Titin
190
In a resting muscle cell, the myosin-binding sites are blocked by \_\_\_\_\_\_.
A) actin
B) troponin
C) titin
D) tropomyosin
D) tropomyosin
191
Which of the following statements is incorrect?
A) The plasma membrane of a muscle cell is called sarcolemma
B) The T tubules are invaginations of the sarcolemma
C) The cytoplasm of a muscle is called sarcoplasm
D) There is cell to cell continuity between a nerve and a muscle fiber at the neuromuscular junction
D) There is cell to cell continuity between a nerve and a muscle fiber at the neuromuscular junction
192
What causes action and myosin filaments to bind to each other?
A) the entry of calcium ions into the the nerve terminal
B) the release of acetylcholine into the synaptic cleft
C) the entry of Na ions into the sarcoplasm
D) the binding of Ca ions to actin filaments to expose the active sites
D) the binding of Ca ions to actin filaments to expose the active sites
193
The first source used to generate ATP when muscles are extremely active is
A) Body fat
B) Aerobic respiration
C) Anaerobic glycolysis
D) Creatine phosphate
D) Creatine phosphate
194
Muscle tone is \_\_\_\_\_\_\_\_.
A) the ability of a muscle to relax following contraction
B) the feeling of well-being following exercise
C) a state of sustained partial contraction
D) the condition of athletes after intensive training
C) a state of sustained partial contraction
195
Creatine phosphate functions in the muscle cell by \_\_\_\_\_\_\_\_.
A) forming a temporary chemical bond with myosin
B) forming a chemical bondwith actin
C) inducing a change in shape of the myofilaments
D) storing energy that will be transferred to ADP to resynthesize ATP
D) storing energy that will be transferred to ADP to resynthesize ATP
196
What is the functional role of the T tubules?
A) stabilize actin
B) enhance cellular communication during muscle contraction
C) hold cross bridges in place in a resting muscle
D) synthesize ATP to provide energy for muscle contraction
B) enhance cellular communication during muscle contraction
197
What produces the striations of a skeletal muscle cell?
A) a difference in the thickness of the sarcolemma
B) the arrangement of myofilaments
C) the sarcoplasmic reticulum
D) the T tubules
B) the arrangement of myofilaments
198
What is resting membrane potential ?
A) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is more positively charged compared to the outside
B) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is less positively charged compared to the outside
C) The action potential that travels across the sarcolemma when a muscle is resting.
D) None of the above
B) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is less positively charged compared to the outside
199
An untrained person, trying to run a marathon, becomes fatigued because of an oxygen debt, and a build up of lactic acid in the body.
True
False
True
200
1. ______ surrounds bundles of fibers
2. ______ surrounds each individual fiber
3. ______ surrounds the entire muscle
1. Perimysium
2. endomysium
3. epimysium
201
Which of the following muscle types is/are both voluntary and striated?
A) skeletal muscle only
B) cardiac muscle and skeletal muscle
C) cardiac muscle only
D) smooth muscle only
A) skeletal muscle only
202
Muscle cells initiate nerve impulses.
True
False
False
_Neurons_ are responsible for initiating nerve impulses.
203
The final "go" signal for skeletal muscle contraction is \_\_\_\_\_\_\_\_\_\_.
A) an increase in extracellular calcium ion levels
B) a decrease in extracellular calcium ion levels
C) a decrease in intracellular calcium ion levels
D) an increase in intracellular calcium ion levels
D) an increase in intracellular calcium ion levels
204
The __________ are inward invaginations of the sarcolemma that run deep into the cell and ensure that every myofibril in the muscle fiber contracts at virtually the same time.
A) Z discs
B) T tubules
C) A bands
D) thin filaments
B) T tubules
205
The thin myofilaments of skeletal muscle are composed chiefly of \_\_\_\_\_\_\_\_\_\_.
A) myosin
B) actin
C) tropomyosin
D) troponin
B) actin
206
Acetylcholinesterase \_\_\_\_\_\_\_\_\_\_.
A) helps acetylcholine bind to its receptor
B) is another name for acetylcholine
C) activates acetylcholine
D) breaks down acetylcholine
D) breaks down acetylcholine
207
**Myofibrils are composed of repeating contractile elements called \_\_\_\_\_\_\_\_\_\_.**
**A) actin**
**B) sarcomeres**
**C) myofilaments**
**D) myosin**
**B) sarcomeres**
208
Which of the following statements is FALSE?
A) During contraction, thin filaments slide past thick filaments so that actin and myosin filaments do not overlap.
B) During contraction, the distance between Z discs of a sarcomere decreases.
C) During contraction, thin filaments slide past thick filaments so that actin and myosin filaments overlap.
D) During contraction, actin-myosin cross bridges form.
A) During contraction, thin filaments slide past thick filaments so that actin and myosin filaments do not overlap.
209
When an action potential arrives at the neuromuscular junction, the most immediate result is \_\_\_\_\_\_\_\_\_\_.
A) a rise in intracellular Ca2+ levels in the muscle fiber
B) the formation of actin-myosin cross bridges
C) the release of acetylcholine from the motor neuron
D) the depolarization of the sarcolemma
C) the release of acetylcholine from the motor neuron
210
If a muscle is applied to a load that exceeds the muscle's maximum tension, \_\_\_\_\_\_\_\_\_\_.
A) the load will be moved by the contraction
B) the contraction is isotonic
C) the muscle length will not change during contraction
D) the muscle length will shorten during contraction
C) the muscle length will not change during contraction
211
Properly controlled skeletal muscle contractions produced by changing the frequency of stimulation and the strength of stimulation are referred to as \_\_\_\_\_\_\_\_\_\_.
A) muscle twitches
B) multiple motor unit summation
C) graded muscle responses
D) wave summation
C) graded muscle responses
212
The most efficient means of producing ATP for muscle contraction is \_\_\_\_\_\_\_\_\_\_.
A) anaerobic glycolysis
B) aerobic respiration
C) anaerobic respiration
D) lactic acid formation
B) aerobic respiration
213
What would occur if a contracting muscle became totally depleted of ATP?
A) The muscle would remain in a contracted state because of an inability to break actin-myosin cross bridges.
B) The muscle would exhibit isometric contraction.
C) The muscle would exhibit isotonic contraction.
D) The muscle would relax and lengthen because of an inability to sustain actin-myosin cross bridges.
A) The muscle would remain in a contracted state because of an inability to break actin-myosin cross bridges.
214
Match the muscle fiber to the appropriate characteristic: *fast oxidative muscle fiber*
A) fatigue resistant
B) moderately fatigue resistant
C) fatigues quickly
B) moderately fatigue resistant
215
Match the muscle fiber to the appropriate characteristic: *fast glycolytic fiber*
A) fatigue resistant
B) moderately fatigue resistant
C) fatigues quickly
C) fatigues quickly
216
Match the muscle fiber to the appropriate characteristic: *slow oxidative muscle fiber*
A) fatigue resistant
B) moderately fatigue resistant
C) fatigues quickly
A) fatigue resistant
217
Which of the following is FALSE regarding smooth muscle?
A) Contraction of smooth muscle is regulated by the autonomic nervous system.
B) Once damaged, smooth muscle is unable to regenerate.
C) Smooth muscle tends to be organized in sheets.
D) Smooth muscle is not striated.
B) Once damaged, smooth muscle is unable to regenerate.
218
# Choose the true statement.
A) Unlike skeletal muscle, contraction in smooth muscle does not involve a sliding filament mechanism.
B) The final signal for contraction in smooth muscle is a rise in extracellular calcium, while the final signal for contraction in skeletal muscle is a rise in intracellular calcium.
C) Smooth muscle depends on the calcium-calmodulin system to regulate contraction, while skeletal muscle relies on the calcium-troponin system to regulate contraction.
D) Unlike skeletal muscle, smooth muscle does not depend on ATP to fuel contractions.
C) Smooth muscle depends on the calcium-calmodulin system to regulate contraction, while skeletal muscle relies on the calcium-troponin system to regulate contraction.
219
Duchenne muscular dystrophy is more common in females than in males.
True
False
False
220
Which structure in the figure corresponds to a single skeletal muscle cell?
A
B
C
D
C
221
Labels the following: *I band*
222
Label the following: *Sarcolemma*
223
Which of the following statements is incorrect?
A) The plasma membrane of a muscle cell is called sarcolemma
B) The T tubules are invaginations of the sarcolemma
C) The cytoplasm of a muscle is called sarcoplasm
D) There is cell to cell continuity between a nerve and a muscle fiber at the neuromuscular junction
D) There is cell to cell continuity between a nerve and a muscle fiber at the neuromuscular junction
224
What causes action and myosin filaments to bind to each other?
A) the entry of calcium ions into the the nerve terminal
B) the release of acetylcholine into the synaptic cleft
C) the entry of Na ions into the sarcoplasm
D) the binding of Ca ions to actin filaments to expose the active sites
D) the binding of Ca ions to actin filaments to expose the active sites
225
Which structure is filled with the neurotransmitter?
Synaptic Cleft
226
The first source used to generate ATP when muscles are extremely active is
A) Body fat
B) Aerobic respiration
C) Anaerobic glycolysis
D) Creatine phosphate
D) Creatine phosphate
227
Muscle tone is \_\_\_\_\_\_\_\_.
A) the ability of a muscle to relax following contraction
B) the feeling of well-being following exercise
C) a state of sustained partial contraction
D) the condition of athletes after intensive training
C) a state of sustained partial contraction
228
Creatine phosphate functions in the muscle cell by \_\_\_\_\_\_\_\_.
A) forming a temporary chemical bond with myosin
B) forming a chemical bondwith actin
C) inducing a change in shape of the myofilaments
D) storing energy that will be transferred to ADP to resynthesize ATP
D) storing energy that will be transferred to ADP to resynthesize ATP
229
What is the functional role of the T tubules?
A) stabilize actin
B) enhance cellular communication during muscle contraction
C) hold cross bridges in place in a resting muscle
D) synthesize ATP to provide energy for muscle contraction
B) enhance cellular communication during muscle contraction
230
What produces the striations of a skeletal muscle cell?
A) a difference in the thickness of the sarcolemma
B) the arrangement of myofilaments
C) the sarcoplasmic reticulum
D) the T tubules
B) the arrangement of myofilaments
231
What is resting membrane potential ?
A) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is more positively charged compared to the outside
B) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is less positively charged compared to the outside
C) The action potential that travels across the sarcolemma when a muscle is resting.
D) None of the above
B) The voltage difference existing across the sarcolemma in a resting muscle, where the inside is less positively charged compared to the outside
232
An untrained person, trying to run a marathon, becomes fatigued because of an oxygen debt, and a build up of lactic acid in the body.
True
False
True
233
Isotonic contraction _______ muscle length.
A) decreases
B) increases
A) decreases
## Footnote
*Muscles shorten during contraction*
234
Isometric contraction __________ muscle tension.
A) decreases
B) increases
B) increases
235
During Isometric contraction muscle _______ during contraction.
A) shortens
B) does not shorten
B) does **_not_** shorten
## Footnote
*The muscle may "bulge" and individual fibers may shorten but **the muscle does not shorten***
236
The first few milliseconds after stimulation before contraction begins.
A) relaxation period
B) Latent period
C) period of contraction
B) Latent period
237
Cross bridges actively form and the muscle shortens.
A) relaxation period
B) Latent period
C) period of contraction
C) period of contraction
238
Ca2+ reenters the SR, and muscle tension returns to zero.
A) relaxation period
B) Latent period
C) period of contraction
A) relaxation period
239
Calcium is released from the terminal cisterns in response to \_\_\_\_\_\_.
A) ATP
B) calcium pumps
C) an action potential
D) troponin
C) an action potential
240
Where is calcium (Ca2) stored?
A) terminal cisterns
B) T-tubules
C) mitochondria
D) sarcoplasmic reticulum
D) sarcoplasmic reticulum
241
**What is the significance of the muscle fiber triad relationship?**
**A) The terminal cisterns subdivide the sarcolemma.**
**B) The T tubules bring calcium to the sarcoplasmic reticulum.**
**C) The sarcoplasmic reticulum transfers calcium to the T tubules.**
**D) The T tubules conduct electrical impulses that stimulate calcium release from the sarcoplasmic reticulum.**
**D) The T tubules conduct electrical impulses that stimulate calcium release from the sarcoplasmic reticulum.**
242
In order to receive a signal to contract, each skeletal muscle must be served by a(n) \_\_\_\_\_\_\_\_.
A) artery
B) nerve
C) vein
D) ligament
B) nerve
243
At the neuromuscular junction, the muscle contraction initiation event is \_\_\_\_\_\_.
A) a release of calcium ions from the sarcoplasmic reticulum
B) conduction of an electrical impulse down the T tubules
C) binding of acetylcholine to membrane receptors on the sarcolemma
D) sliding of actin and myosin filaments past each other
C) binding of acetylcholine to membrane receptors on the sarcolemma
244
What would be the first response of a muscle fiber treated with an acetylcholinesterase inhibitor?
A) The muscle fiber would continue to contract in the absence of additional nervous system stimulation.
B) The muscle fiber would be nonresponsive to acetylcholine.
C) Acetylcholine would be retained in the axon terminal.
D) The muscle fiber would continuously contract for a prolonged period of time.
A) The muscle fiber would continue to contract in the absence of additional nervous system stimulation.
245
Corpses usually exhibit rigor mortis because \_\_\_\_\_\_.
## Footnote
A) ATP hydrolysis is stimulating myosin head attachment to actin
B) a lack of ATP hydrolysis prevents myosin head detachment from actin
C) calcium stores become deficient
D) sodium stores become deficient
B) a lack of ATP hydrolysis prevents myosin head detachment from actin
246
T tubules are an extension of the \_\_\_\_\_\_\_\_\_.
A) sarcomere
B) sarcoplasmic reticulum
C) sarcolemma
D) endomysium
C) sarcolemma
247
**Calcium is released from the terminal cisterns in response to \_\_\_\_\_\_.**
**A) ATP**
**B) calcium pumps**
**C) an action potential**
**D) troponin**
**C) an action potential**
248
In a muscle fiber, the key intracellular event that stimulates muscle contraction is known as \_\_\_\_\_\_.
A) polarization
B) depolarization
C) repolarization
D) potential
B) depolarization
249
During depolarization, the sarcolemma is most permeable to \_\_\_\_\_\_.
A) sodium ions
B) potassium ions
C) calcium ions
D) chloride ions
A) sodium ions
250
Activities that require a brief surge of power rely entirely on direct phosphorylation and ATP stores.
A) Tennis, 100 meter swiming, football
B) Weight lifting, sprinting
C) Marathon runners, jogging
B) Weight lifting, sprinting
251
Activities that require on-off surges of power for longer periods rely entirely on anaerobic glycolysis
A) Tennis, 100 meter swiming, football
B) Weight lifting, sprinting
C) Marathon runners, jogging
A) Tennis, 100 meter swiming, football
252
Activities that require prolonged endurance rely primarily on aerobic respiration
A) Tennis, 100 meter swiming, football
B) Weight lifting, sprinting
C) Marathon runners, jogging
C) Marathon runners, jogging
253
How much energy released in muscle activity is useful as work?
A) 60%
B) 40%
B) 40%
## Footnote
*60% is given off as heat*
254
Does not cause skeletal muscle hypertrophy.
A) resistance exercise
B) aerobic exercise
A) resistance exercise
255
Small precise movements are controlled by ______ motor units.
A) small
B) large
C) many
D) few
A) small
256
Isometric contractions come into play when an individual is \_\_\_\_\_\_\_\_.
A) jumping
B) walking uphill
C) moving a heavy object
D) maintaining an upright posture
D) maintaining an upright posture
257
A major cellular feature in smooth muscle that contributes to its rhythmicity and ability to participate in peristalsis is the presence of \_\_\_\_\_\_.
A) troponin complex
B) gap junctions
C) varicosities
D) caveolae
B) gap junctions
258
The principal neurotransmitter of skeletal muscle is acetylcholine. The major neurotransmitter(s) of smooth muscle is (are) \_\_\_\_\_\_\_.
A) acetylcholine
B) epinephrine
C) norepinephrine
D) all of the above
D) all of the above
259
What substance must bind to myosin heads in order for the heads to detach from the thin filaments?
A) Calcium
B) ATP
C) Troponin
D) Sodium
B) ATP
260
In a resting muscle cell, the myosin-binding sites are blocked by \_\_\_\_\_\_.
A) actin
B) troponin
C) titin
D) tropomyosin
D) tropomyosin
261
T-Tubules are an extension of the \_\_\_\_
A) sarcoplasmic reticulum
B) sarcomere
C) sarcolemma
D) tendon
C) sarcolemma
262
Which of the following best describes the events of "excitation" in "excitation-contraction coupling"?
A) propagation of the action potential along the sarcolemma
B) cross bridge formation
A) propagation of the action potential along the sarcolemma
263
Which of the following best describes the events of "contraction" in "excitation-contraction coupling"?
A) propagation of the action potential along the sarcolemma
B) cross bridge formation
B) cross bridge formation
264
The hydrolysis of the ATP that is bound to myosin causes:
A) Irreversible binding of myosin to the actin filament
B) Phosphorylation of the actin filament
C) Release of myosin head from the actin filament
D) Reversible binding of myosin to the actin filament
C) Release of myosin head from the actin filament
265
What is the role of tropomyosin in muscle contraction?
A) To aid in myosin ‘cocking’ on the actin filament
B) To release troponin from tropomyosin, allowing myosin to bind to the actin filament
C) To prevent myosin from continuing to slide up the actin filament
D) To release calcium from the sarcoplasmic reticulum
C) To prevent myosin from continuing to slide up the actin filament
266
What is the role of acetylcholine in calcium release?
A) Stimulates cellular contraction by opening voltage-gated ion channels
B) Stimulates postsynaptic acetylcholine receptors to release intracellular calcium
C) Binds to sarcoplasmic reticulum, causing calcium release
D) Binds to the sarcolemma, causing calcium release
A) Stimulates cellular contraction by opening voltage-gated ion channels
267
Which of the following correctly identifies muscle components in order from largest to smallest?
A) Fasciculus, muscle bundle, myofibril
B) Fasciculus, muscle fiber, myofibril
C) Sarcolemma, sarcoplasm, fasciculus
D) Muscle fiber, fasciculus, myofibril
B) Fasciculus, muscle fiber, myofibril
268
**The space between two Z lines constitutes the:**
**A) Sarcolemma**
**B) Sarcoplasm**
**C) Sarcomere**
**D) Sarcophagus**
**C) Sarcomere**
269
What is an aponeurosis?
A) An area of smooth muscle in the abdomen
B) A segment of muscle that is not attached to bone
C) A large, flat tendon that anchors muscle
D) A group of neurons that innervate striated muscle cells
C) A large, flat tendon that anchors muscle
270
We would expect to find smooth muscle in all of the following EXCEPT:
A) Esophagus
B) Myocardial tissue
C) Pulmonary circulatory tissue
D) Small intestine
B) Myocardial tissue
271
Curare is a naturally-occurring compound that competitively binds to nicotinic acetylcholine receptors on muscle cells. Which of the following symptoms might be seen in a patient who has been exposed to curare?
A) Muscle spasticity
B) Diaphragmatic paralysis
C) Excessive salivation
D) Cardiac arrest
B) Diaphragmatic paralysis
272
Which of the following is accurate regarding Type I and Type II muscle fibers?
A) Type I fibers are white, whereas Type II fibers are red
B) Type I fibers employ anaerobic metabolism, whereas Type II fibers utilize aerobic metabolism
C) Type I fibers store much of their energy as triglycerides, whereas Type II fibers store energy as ATP or creatine phosphate
D) Type I fibers are easily fatigued and are therefore intended for short bursts of activity
C) Type I fibers store much of their energy as triglycerides, whereas Type II fibers store energy as ATP or creatine phosphate
273
Which of the following is NOT innervated by the autonomic nervous system?
A) Intestinal muscle cell
B) Myocardial cell
C) Branching muscle cell
D) Striated muscle cell
D) Striated muscle cell
274
Binding of ACh to a nicotinic receptor on the motor end plate will cause the muscle cell membrane potential to:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
275
During muscle contraction, the overlap between actin and myosin will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
276
During muscle contraction, the size of the A band will:
A) Increase
B) Decrease
C) Stay the same
C) Stay the same
277
During muscle relaxation, the size of the H zone will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
278
During muscle contraction, the width of the I band will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
279
In response to calcium release from the SR, the number of available myosin binding sites on actin will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
280
Binding of ACh to a nicotinic receptor on the motor end plate will cause the calcium levels in the sarcoplasmic reticulum to:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
281
During muscle relaxation, the distance between adjacent Z discs will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
282
During sarcomere contraction, the size of the I band will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
283
During sarcomere contraction,the size of the A band will:
A) Increase
B) Decrease
C) Stay the same
C) Stay the same
284
During sarcomere contraction, the size of the H zone will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
285
In response to an action potential travelling down a t-tubule, the amount of calcium in the neighboring terminal cisterna will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
286
An increase in sarcoplasm calcium levels will cause the number of myosin-binding sites on actin that are blocked by tropomyosin to:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
287
During muscle cell relaxation, the amount of overlap between the thin and thick filaments will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
288
Binding of nicotine to the receptor on the motor end plate will cause the membrane potential to:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
289
A drug that blocked acetylcholinesterase would cause ACh levels in the synaptic cleft of a neuromuscular junction to:
A) Increase
B) Decrease
C) Stay the same
A) Increase
290
The arrival of an action potential that the axon terminal of a somatic motor neuron would cause the amount of ACh in the axon terminal to:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
291
An increase in the number of motor units activated in a skeletal muscle will cause the tension generated by that skeletal muscle to:
A) Increase
B) Decrease
C) Stay the same
A) Increase
292
During an isotonic eccentric muscle contraction, tension is generated and maintained as muscle length:
A) Increase
B) Decrease
C) Stay the same
A) Increase
293
As a result of endurance training, the capillary density of a skeletal muscle will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
294
As a result of resistance training, the number of myofibrils per muscle fiber will:
A) Increase
B) Decrease
C) Stay the same
A) Increase
295
As Brock sprints 100 meters, the amount of glycogen in the muscle fibers of his hamstrings will:
A) Increase
B) Decrease
C) Stay the same
B) Decrease
296
Which of the following is a characteristic of muscle cells?
A) Excitability
B) Contractility
C) Elasticity
D) Extensibility
E) All of the above
E) All of the above
297
If the muscle fiber was stimulated again at time=50ms, the tension generated in response would exceed the tension generated in the initial twitch.
True
False
True
298
At time=\_\_\_\_\_\_\_ms, the muscle cell is in its latent period.
A) 2
B) 18
C) 35
D) 120
E) 150
A) 2
299
At time=60ms, calcium is actively being pumped into the sarcoplasmic reticulum
True
False
True
300
Which of the following stabilizes the thick filaments in a myofibril?
A) Z disc
B) Z line
C) A band
D) M line
E) H zone
D) M line
301
Which of the following binds calcium during excitation-contraction coupling?
A) Tropomyosin
B) Actin
C) Myosin
D) Troponin
E) All of the above
D) Troponin
302
Which of the following must myosin bind in order to let go of actin?
A) Calcium
B) Troponin
C) ATP
D) ADP
E) Inorganic phosphate
C) ATP
303
A muscle fiber and all of the axon terminals that synapse with it are collectively referred to as a motor unit.
True
False
False
## Footnote
*A motor unit consists of one motor neuron and all the muscle fibers it innervates*
