Chapter 08 – Muscle Physiology
1. Approximately what percentage of body weight does muscle comprise?
a.
20%
b.
35%
c.
50%
d.
70%
e.
85%
c
8.1 Structure of Skeletal Muscle
HUPH.SHER.16.8.6 – Describe the structure of skeletal muscles
2. What are the three main muscle types?
a.
skeletal, rough, and smooth
b.
flexion, extension, and rotation
c.
skeletal, cardiac, and smooth
d.
thick, thin, and flat
e.
skeletal, arterial, and venous
c
8.1 Structure of Skeletal Muscle
HUPH.SHER.16.8.6 – Describe the structure of skeletal muscles
3. What types of muscles are involuntary in terms of movement?
a.
b.
c.
d.
e.
a
8.1 Structure of Skeletal Muscle
HUPH.SHER.16.8.6 – Describe the structure of skeletal muscles
4. During the embryonic developmental stage, skeletal muscle fibers are derived from:
a.
fibroblasts
b.
lymphoblasts
c.
connective tissue
d.
myoblasts
e.
microfilaments
HUPH.SHER.16.8.6 – Describe the structure of skeletal muscles
5. What molecules form the thick filaments within muscle?
Chapter 08 – Muscle Physiology
a.
microfilaments
b.
myosin
c.
actin
d.
myoblasts
e.
troponin
8.1 Structure of Skeletal Muscle
HUPH.SHER.16.8.6.1 – Describe the five levels of organization in a skeletal muscle
6. What shape are actin molecules?
a.
elongated
b.
spherical
c.
bicuspid
d.
rectangular
e.
triangular
8.1 Structure of Skeletal Muscle
HUPH.SHER.16.8.6.2 – Describe the three proteins that constitute thin filaments
7. What two molecules participate in cross-bridge interactions?
a.
tropomyosin and myosin
b.
troponin and myosin
c.
troponin and tropomyosin
d.
actin and myoblasts
e.
actin and myosin
e
8.2 Molecular Basis of Skeletal Muscle Contraction
HUPH.SHER.16.8.7.3 – Describe the sliding filament mechanism of muscle contraction
8. During muscle contraction, what becomes smaller?
a.
H zone
b.
thin filaments
c.
the width of the A band
d.
thick filaments
e.
myosin molecules
a
8.2 Molecular Basis of Skeletal Muscle Contraction
HUPH.SHER.16.8.7.3 – Describe the sliding filament mechanism of muscle contraction
9. How many “heads” does each myosin molecule have?
Chapter 08 – Muscle Physiology
a.
5
b.
4
c.
3
d.
2
e.
1
d
8.2 Molecular Basis of Skeletal Muscle Contraction
10. How many thin filaments are on each end of a sarcomere?
a.
6
b.
5
c.
4
d.
3
e.
2
a
8.2 Molecular Basis of Skeletal Muscle Contraction
11. What are the two membranous structures within the muscle fiber that play important roles in linking excitation to
contraction?
a.
horizontal tubules and sarcoplasmic reticulum
b.
transverse tubules and sarcoplasmic reticulum
c.
transverse tubules and endoplasmic reticulum
d.
horizontal tubules and endoplasmic reticulum
e.
sarcolemma and plasma end plates
b
8.2 Molecular Basis of Skeletal Muscle Contraction
12. Which molecule binds ATP in order for muscle contraction to occur?
a.
sarcolemma
b.
actin
c.
myosin
d.
calcium
e.
phosphate
c
8.2 Molecular Basis of Skeletal Muscle Contraction
13. How long does a single action potential in a skeletal muscle fiber last?
a.
1 to 2 seconds
b.
0.5 seconds
c.
5 milliseconds
d.
1 to 2 milliseconds
e.
0.5 milliseconds
8.2 Molecular Basis of Skeletal Muscle Contraction
14. How many skeletal muscles are there in the body?
a.
about 400
b.
442
c.
about 500
d.
535
e.
about 600
e
8.3 Skeletal Muscle Mechanics
HUPH.SHER.16.8.8 – Describe the contraction of whole muscles
15. Muscle tension is produced internally within the ____.
a.
myosin molecules
b.
actin molecules
c.
T tubules
d.
sarcoplasmic reticulum
e.
sarcomeres
e
8.3 Skeletal Muscle Mechanics
HUPH.SHER.16.8.8.1 – Describe how muscle tension is transmitted to a bone
16. What happens to a muscle during an isometric contraction?
a.
It produces more calcium.
b.
It lengthens.
c.
It shortens.
d.
It is prevented from shortening.
e.
Sarcomeres are destroyed.
17. The portion of a lever between the fulcrum and the point where a force is applied by the muscle is called the ____.
a.
fulcrum angle
b.
velocity
c.
power arm
d.
load arm
e.
interactive unit
c
8.3 Skeletal Muscle Mechanics
HUPH.SHER.16.8.8.3 – Explain the lever systems of muscles, bones, and joints
18. One motor neuron, plus all the muscle fibers it innervates, is known as a(n):
a.
nerve bundle
b.
motor unit
c.
activated component
d.
cross bridge
e.
functional unit
8.3 Skeletal Muscle Mechanics
19. What happens when two or more overlapping action potentials are “added” together within a muscle?
a.
twitch fatigue
b.
twitch summation
c.
contraction addition
d.
contraction paralysis
e.
sarcoplasmic reduction
8.3 Skeletal Muscle Mechanics
developed by each contracting muscle fiber
20. Because of skeletal constraints, what is the maximum percentage that muscles can stretch or shorten relative to their
length?
a.
30%
b.
35%
c.
40%
d.
45%
e.
50%
8.3 Skeletal Muscle Mechanics
HUPH.SHER.16.8.8.2 – Describe the three primary types of contractions
Chapter 08 – Muscle Physiology
a
8.3 Skeletal Muscle Mechanics
21. How many steps in the muscle excitation, contraction, and relaxation processes require ATP?
a.
3
b.
4
c.
5
d.
6
e.
7
b
8.4 Skeletal Muscle Metabolism and Fiber Types
HUPH.SHER.16.8.9 – Describe the four steps that require adenosine triphosphate (ATP)
22. How many additional pathways supply ATP as needed during muscle contraction?
a.
1
b.
2
c.
3
d.
4
e.
5
c
8.4 Skeletal Muscle Metabolism and Fiber Types
23. What is the first source for supplying additional ATP when exercise begins?
a.
oxidative phosphorylation
b.
glycolysis
c.
lactate
d.
creatine phosphate
e.
chondroitin
d
8.4 Skeletal Muscle Metabolism and Fiber Types
24. What are the two main types of fatigue?
a.
skeletal and cardiac
b.
skeletal and smooth
c.
muscle and cerebral
Chapter 08 – Muscle Physiology
d.
muscle and psychological
e.
muscle and central
e
8.4 Skeletal Muscle Metabolism and Fiber Types
HUPH.SHER.16.8.9.2 – Describe the two types of fatigue
25. What hormone, elevated during exercise, increases oxygen consumption?
a.
dopamine
b.
serotonin
c.
acetylcholine
d.
norepinephrine
e.
epinephrine
e
8.4 Skeletal Muscle Metabolism and Fiber Types
26. What are the two types of fast-twitch muscle fibers?
a.
oxidative and phosphoric
b.
oxidative and glycolytic
c.
pyruvic and glycolytic
d.
acetic and glycolytic
e.
fast and slow
8.4 Skeletal Muscle Metabolism and Fiber Types
HUPH.SHER.16.8.9.4 – Describe the three types of skeletal muscle fibers
27. What is the least complex type of purposeful motor movement?
a.
somatic reflex responses
b.
voluntary movements
c.
rhythmic activities
d.
tetanus contraction
e.
fine motor movements
a
8.5 Control of Motor Movement
HUPH.SHER.16.8.10 – Summarize the mechanism involved in controlling motor movements
28. What level of neural input (to motor neurons) involves pyramidal cells?
a.
input from the brain stem
b.
input from the efferent neurons
c.
input from afferent neurons
Chapter 08 – Muscle Physiology
d.
input from the sensory cortex
e.
input from the primary motor cortex
8.5 Control of Motor Movement
29. What plays a key role in mediating performance of fine, discrete, voluntary movements of the hands and fingers?
a.
premotor area
b.
supplementary motor area
c.
multineuronal system
d.
corticospinal system
e.
the pons
8.5 Control of Motor Movement
30. What do the basal nuclei coordinate?
a.
slow twitch muscle fibers
b.
spinal reflexes
c.
slow, sustained movement
d.
fast movement
e.
fast twitch muscle fibers
8.5 Control of Motor Movement
their output to the muscle fibers
31. Loss of descending inhibitory inputs on motor neurons may result in ____.
a.
spastic paralysis
b.
flaccid paralysis
c.
tetanus
d.
clumsy movement
e.
cerebral palsy
8.5 Control of Motor Movement
32. Damage to the cerebellum or basal nuclei results in ____.
Chapter 08 – Muscle Physiology
a.
spastic paralysis
b.
flaccid paralysis
c.
tetanus
d.
clumsy movement
e.
cerebral palsy
d
8.5 Control of Motor Movement
33. For effective control of motor output, what two types of muscle proprioceptors are needed by the CNS?
a.
muscle spindles and Golgi tendon organs
b.
muscle spindles and stretch receptors
c.
sarcoplasmic reticulum and Golgi tendon organs
d.
sarcomeres and Golgi tendon organs
e.
sarcomeres and stretch receptors
a
8.5 Control of Motor Movement
34. How developed is the sarcoplasmic reticulum in cardiac muscle?
a.
non-existent
b.
poorly developed
c.
moderately developed
d.
well developed
e.
heavily developed
c
8.6 Smooth and Cardiac Muscle
HUPH.SHER.16.8.11 – Compare smooth and cardiac muscles with skeletal muscle
35. How many filament types do smooth muscle cells have?
a.
2
b.
3
c.
4
d.
5
e.
6
b
8.6 Smooth and Cardiac Muscle
HUPH.SHER.16.8.11.1 – Describe the three types of filaments in smooth muscles
36. What kind of smooth muscle contracts in bursts?
a.
phasic
b.
tonic
c.
clonic
d.
cardiac
e.
vascular
a
8.6 Smooth and Cardiac Muscle
HUPH.SHER.16.8.11.2 – Contrast phasic smooth muscle with tonic smooth muscle
37. Contractile activity in both skeletal muscle and multiunit smooth muscle is ____.
a.
myogenic
b.
phasic
c.
tonic
d.
clonic
e.
neurogenic
e
8.6 Smooth and Cardiac Muscle
HUPH.SHER.16.8.11.3 – Compare multiunit to single-unit smooth muscles
38. What are the two major types of spontaneous depolarizations displayed by self-excitable cells?
a.
fast-wave and slow-wave potentials
b.
membrane potentials and slow-wave potentials
c.
pacemaker potentials and slow-wave potentials
d.
smooth potentials and fast-wave potentials
e.
cardiac potentials and fast-wave potentials
c
8.6 Smooth and Cardiac Muscle
HUPH.SHER.16.8.11.3 – Compare multiunit to single-unit smooth muscles
39. What does smooth muscle contain that enables it to stretch much more than skeletal muscle?
a.
calcium
b.
glucosamine
c.
sarcomeres
d.
connective tissue
e.
microfilaments
40. What phenomenon enables smooth muscle to maintain tension with comparatively less ATP consumption, as
Chapter 08 – Muscle Physiology
compared to skeletal muscle?
a.
stretch phenomenon
b.
jump phenomenon
c.
piggy back phenomenon
d.
click phenomenon
e.
latch phenomenon
e
8.6 Smooth and Cardiac Muscle
41. Muscles are categorized as striated (skeletal and cardiac muscle) or unstriated (smooth muscle).
a.
True
b.
False
True
8.1 Structure of Skeletal Muscle
HUPH.SHER.16.8.6 – Describe the structure of skeletal muscles
42. Viewed with an electron microscope, a myofibril displays alternating dark bands (the A bands) and light bands (the I
bands).
a.
True
b.
False
True
8.1 Structure of Skeletal Muscle
HUPH.SHER.16.8.6.1 – Describe the five levels of organization in a skeletal muscle
43. Myofibrils are made from thick and round filaments.
a.
True
b.
False
False
8.1 Structure of Skeletal Muscle
HUPH.SHER.16.8.6.1 – Describe the five levels of organization in a skeletal muscle
44. Tropomyosin molecules are threadlike proteins that lie end to end alongside the groove of the actin spiral.
a.
True
b.
False
True
8.1 Structure of Skeletal Muscle
HUPH.SHER.16.8.6.2 – Describe the three proteins that constitute thin filaments
45. Tropomyosin and troponin are often called stimulation proteins because of their role in covering or exposing the
Chapter 08 – Muscle Physiology
binding sites for cross-bridge interaction between actin and myosin.
a.
True
b.
False
False
46. Both the thin and thick filaments change length during muscle fiber shortening.
a.
True
b.
False
False
47. On binding to actin, the myosin head tilts 45 degrees inward.
a.
True
b.
False
True
48. Ca2+ binding to tropomyosin causes myosin to change shape, physically moving it away from its blocking position.
a.
True
b.
False
False
49. The action potential is over before the contractile apparatus even becomes operational.
a.
True
b.
False
True
50. In an isokinetic contraction, the load remains constant as the muscle changes length.
a.
True