1. The study of muscles is called: _____________________________
2. Name 4 characteristics of muscle tissue.
_____________________________
_____________________________
_____________________________
_____________________________
3. A ___________________ stimulus is strong enough to initiate a response
while a _________________ stimulus is not strong enough to initiate a response.
4. List 3 functions of muscles.
_____________________________
_____________________________
_____________________________
5. Any change in one's internal or external environments is a(n):____________________________.
6. ATP + Eact -----------------> _______
+ __________ + ____________.
7. Identify the muscle type based on the descriptions given below.
a. Multinucleate.
_____________________________
b. Cell is spindle-shaped.
_____________________________
c. Striated and uninucleate.
_____________________________
d. Usuually attached to bone.
_____________________________
e. Unstriated.
_____________________________
f. Found in the heart.
_____________________________
g. Anastomosing fibers.
_____________________________
h. Peripherally located nuclei.
_____________________________
i. Centrally located nucleus.
_____________________________
j. Muscle fibers elongate in shape;
voluntary. _____________________________
k. Intercalated discs present.
_____________________________
l. Found in the walls of visceral organs.
_____________________________
8. Rank the following structures from largest to smallest: muscle fiber,
myofibril, myofilament, muscle belly, fascicle, and sarcomere.
_____________________________
_____________________________
_____________________________
_____________________________
_____________________________
_____________________________
9. Identify the parts of muscle macrostructure based on the descriptions
given below.
a. Large middle region of the muscle.
_____________________________
b. Connective tissue that wraps around a fascicle.
_____________________________
c. Discrete bundle of muscle cells separated
by connective tissue. _____________________________
d. Muscle fiber.
_____________________________
e. Connective tissue wrapping around an individual
muscle cell. _____________________________
f. Connective tissue wrapping around whole
muscle. _____________________________
g. Protective and provide entrance and exits
for blood vessels and nerve fibers. _____________________________
h. Cord of connective tissue that attaches
muscle to periosteum of bone. _____________________________
i. A broad, flat tendon.
_____________________________
j. Fixed point of attachment for muscle.
_____________________________
k. Movable point of attachment for muscle.
_____________________________
10. Inflammation of tendon sheaths and synovial membranes of joints
is called:_________________.
11. Identify the parts of muscle microstructure based on the descriptions
given below.
a. Muscle fiber.
_____________________________
b. Cytoplasm of a muscle cell.
_____________________________
c. Smooth endoplasmic reticulum of a muscle
cell. _____________________________
d. Plasma membrane of muscle cell.
_____________________________
e. Main source of ATPs for muscle metabolism.
_____________________________
f. Stores Ca++.
_____________________________
g. Transverse indentations of the sarcolemma.
_____________________________
h. Enlarged sac-like end of the SR.
_____________________________
i. Elongate contractile structures in a muscle
cell. _____________________________
j. Functional unit of muscle contraction.
_____________________________
k. Conducts action potential towards interior
of cell. _____________________________
12. Identify the parts of a myofibril based on the descriptions given
below.
a. Area between 2 adjacent Z lines.
_____________________________
b. Thick myofilament.
_____________________________
c. Thin myofilament.
_____________________________
d. Area of sarcomere that represents length
of thick myofilaments. _____________________________
e. Area divided by a Z line that includes
thin myofilaments. ___________________________
f. Disc-like protein sheet used for attachment
of actin proteins.________________________
g. Light area in the middle of an A band.
_____________________________
h. Area of A band where actin is absent.
_____________________________
13. A myosin myofilament is composed of ~ 200 molecules of the protein
__a__. Each __a__ protein is shaped like a two-headed golf club.
The shaft is referred to as the __b__ while the heads are referred to as
__c__ or __d__. These 200 molecules of __a__ are bundled together
with the __b__ pointing to the __e__ (ends/middle) and the __c__
facing __f__ (in/out). Because of this arrangement the middle of
the myosin myofilament without __d__ is known as the __g__.
a. ___________________________ e. ___________________________
b. ___________________________ f. ____________________________
c. ___________________________ g. ___________________________
d. ___________________________
14. An actin myofilament is composed of 3 proteins. The main
protein is called __a__. __a__, also known as __b__, is polymerized
from __c__ . Each __c__ is globular in shape and has an __d__ site
that bonds with the myosin head. __e__ (1, 2, 3, etc.) strands of
__b__ coil around each other. A second rod-shaped protein called
__f__ spirals around the __a__ helix. At evenly spaced increments
along the length of the actin myofilament is a third protein called __g__.
__g__ is composed of 3 polypeptides: the __h__ unit binds to the
actin; the __i__ unit binds to the __f__, and the third unit called __j__
binds __k__ ions.
a. ___________________________ f. ___________________________
b. ___________________________ g. ____________________________
c. ___________________________ h. ___________________________
d. ___________________________ i. ____________________________
e. ___________________________ j. ____________________________
k. ____________________________
15. The cross-bridges of the myosin myofilaments act like which enzyme?
_____________________
16. List 3 observations available to researchers that contributed to
the formulation of the sliding filament theory of muscle contraction.
___________________________________
___________________________________
___________________________________
17. List, in the correct sequence, the 4 main events that cause actin
and myosin to slide past each.
_____________________________
_____________________________
_____________________________
_____________________________
18. Fill in the blanks regarding the steps of the
sliding filament theory.
A resting muscle cell has a low concentration of __a__ ions in
its __b__. __a__ ions are in high concentration in the __c__.
When __a__ ions are in low concentration, myosin-binding sites on the G
actins are covered by __d__ molecules. Stimulation from a nerve impulse
causes __a__ ions to be released from the __c__. __a__ ions bind
to __e__ and cause a conformational change that physically removes __d__
from blocking active sites (=myosin-binding sites) on G actins. The
myosin __f__ are attracted to the exposed (active) sites. This event is
called __g__. The myosin __f__ changes from a __h__ (high/low)
energy state to a __i__ (high/low) E state. This event is called the __j__.
The __j__ pulls on the thin filament and slides it towards the center of
sarcomere. When the __j__ reaches the __k__ (high/low) energy state, __l__
generated during the previous contraction cycle, are released from
the myosin __f__. A new __m__ binds to the myosin __f__ and this
releases the __f__ from the actin binding sites. This event is called
__n__. The myosin __f__ enzymatically breaks down the __m__
molecule and the released energy is used to change the myosin __f__ back
to the __o__ (high/low) state. This event is called __p__. The events
__g__, __j__, __n__, and __p__ are repeated until maximal shortening is
acheived. The cycle is terminated when nervous stimulation stops
and a __q__ removes Ca++ from the __b__.
a. ___________________________ j. ___________________________
b. ___________________________ k. ____________________________
c. ___________________________ l. ___________________________
d. ___________________________ m. ___________________________
e. ___________________________ n. ____________________________
f. ___________________________ o. ___________________________
g. ___________________________ p. ____________________________
h. ___________________________ q. ___________________________
i. ___________________________
19. A single power stroke gives a ____% reduction in muscle cell length,
but a muscle shortens to between __________ %.
20. Only about _________ (1/8,1/4, 1/2, etc.) the myosin heads are
bonding at any one instant.
21. __a__ is the stiffening of muscles several hours after death. Dead
cells cannot keep __b__out of the sacromere, the availability of these
ions results in __c__. With depletion of __d__ stores and the inability
to synthesize to more __d__ the __e__ cannot detach. Bacterial breakdown
of __f__ causes the body to become limp.
a. ___________________________ d. ___________________________
b. ___________________________ e. ____________________________
c. ___________________________ f. ___________________________
22. The series of events by which electrical excitation of the sarcolemma
leads to contraction is called: _____________________________.
23. The junction between a nerve cell and a muscle cell is called a(n):
____________________ junction.
24. Identify the parts of the myoneural junction based on the
descriptions given below.
a. The enlarged terminal end of a nerve cell.
_____________________________
b. Space between end of nerve cell and muscle
cell. _____________________________
c. Region of sarcolemma at myoneural junction.
_____________________________
d. Structures within enlarged terminal end
of nerve cell that house neurotransmitter. _____________________________
25. Calsequestrin is a protein that: _________________________________________
26. ________________________ is the neurotransmitter released
at myoneural junctions.
27. _________________, a S. American tree resin is a competitive
inhibitor with ACh.
28. ___________________ is an autoimmune disease that results
in the production of antibodies that block ACh receptors.
29. ___________________ is a protein found in the sarcoplasm that binds
Ca++ ions.
30. A nerve impulse arrives at the end of the axon in a region called
the __a__. The __a__ houses __b__ that contain the neurotransmitter __c__.
This nerve impulse causes an influx of __d__ ions that trigger a series
of events resulting in the __e__ of __c__ into the space between cells
called the __f__. __c__ diffuses across the __f__ and binds to receptors
on the __g__. This may result in __h__ of the sarcolemma. This
wave of __h__ travels to the interior of the muscle by the __i__ system
and causes the __j__ of the sarcoplasmic reticulum to release __k__ ions
into the __l__. The __c__ on the __g__ is destroyed by the enzyme
__m__. __k__ ions bind to troponin C and initiate the evnts
of muscle contraction.
a. ___________________________ h. ___________________________
b. ___________________________ i. ____________________________
c. ___________________________ j. ___________________________
d. ___________________________ k. ___________________________
e. ___________________________ l. ____________________________
f. ___________________________ m. ___________________________
g. ___________________________
31. A motor neuron and all the muscle fibers it innervates is called
a(n):_______________________.
There are as few as _____ (1, 2, 3, etc) of these units in eye muscles
and as many as several ____ (dozen, 100's, 1000's etc) in thigh muscles.
32. Muscle fibers in a single motor unit _______________ (are
not/are) clustered together.
Therefore, stimulation of a single unit gives a _______ (strong/weak)
contraction throughout the entire muscle.
33. Answer the following questions regarding a muscle twitch or graded
responses.
a. Graphical recording of muscle activity
. ____________________________
b. Two stimuli of identical strengths given
in rapid succession, the second before the relaxation phase is
completed; second wave rides on first.
____________________________
c. Response of a muscle to a single threshold
stimulus. ____________________________
d. Shortening of muscle fibers to peak tension-lasts
10-100 ms. ______________________
e. Increasing voltage given brings in
more motor units. ____________________________
f. Time following stimulation where
excitation-contraction coupling begins; lasts a few ms.
____________________________
g. Some motor units are contract while
others are relax producing a smooth, even contraction. ____________________________
h. Many stimuli of the same strength given
in rapid sucession before relaxation period is complete. ____________________________
i. Many stimuli of the same strength given
in rapid sucession at end of contraction phase, just before relaxation
period
starts.
____________________________
j. Lengthening of muscle fibers to original
state; tension returns to zero-lasts over 100 ms. ____________________________
k. Multiple stimuli of the same strength given
in rapid sucession, immediately after relaxation period is
complete; Produces staircase effect.
____________________________
34. An involuntary, painful, prolonged contraction is called a(n): ____________________________.
35. Give 2 causes for treppe and wave summation.
____________________________
____________________________
36.Force exerted by muscle on some object is termed: ____________________________
37. Resisting force or weight is termed the: ____________________________
38. Movement is accomplished when the ________________ exceeds the
__________________.
39. If the load is greater than the tension the contraction is: ____________________________.
40. If the tension exceeds the load and the load moves the contraction
is: ____________________.
41. The greatest tension is produced when the maximum number of __a__
link actin and myosin myofilaments. Stretching beyond 175% of muscle
resting length results in __b__ (no, some, maximal) tension while
lengths less than 50% of resting length jam the myosin myofilaments into
the __c__ and __d__ (reduces/increases) muscle tension.
a. ___________________________ c. __________________________
b. ___________________________ d. __________________________
42. During strenuous muscle activity muscle cells use 3 energy molecules.
Name these in the order they are used.
_____________________________
_____________________________
_____________________________
43. Creatine phosphate + _____ ------------(Ez:
_______________)-----> _____________ + ATP
44. Normal muscle activity uses _________________ to generate
ATPs.
45. Name the 3 major pathways in cellular respiration.
_____________________________
_____________________________
_____________________________
46. During strenuous activity, metabolism shifts from fatty acids
to: ________________________.
47. The endproduct of glycolysis is:
____________________________.
48. Two energy molecules produced by glycolysis are:
____________________________
____________________________
49. Glycolysis is an ____________________ (aerobic/anaerobic)
pathway.
50. If oxygen is absent pyruvate is converted to: ____________________________.
51. If oxygen is present the pyruvate enters the: ____________________________.
52. Name 3 energy molecules produced from the Kreb's Cycle.
____________________________
____________________________
____________________________
53. Two waste products formed by the Kreb's Cycle are: _______________
and ______________.
54. The NADH2's and FADH2's produced by glycolysis and the Kreb's
Cycle provide ______________ and _______________ for the electron transport
system.
55. The ETS generates ATPs by the process called: ____________________________.
56. Nearly _____ (2, 3, 4 etc.) times more ATPs are produced during
aerobic as opposed to anaerobic respirations. However, ATP are made
approximately ______ (2, 3, 4 etc.) times faster by __________ respiration.
57. The physiological inability of a muscle to contract is: ___________________________.
58. Name 3 factors that contribute to muscle fatigue.
___________________________
___________________________
___________________________
59. ________________________ is the extra amount of oxygen that must
be taken in by the body to provide for restoring lowered reserves of ATP,
CP, glycogen and for removal of lactic acid.
60. Identify the type of skeletal muscle fiber based on the descriptions
given below.
a. Very high myoglobin content; Splits
ATP rapidly. _____________________________
b. High myoglobin, Splits ATP slowly.
_____________________________
c. Low myoglobin and few capillaries.
_____________________________
d. Splits ATP rapidly; large glycogen
reserves. _____________________________
e. Found in eye and hand muscles; Many
capillaries. _____________________________
f. Few mitochondria, fatigue easily.
_____________________________
g. Color pale or white; Contraction
velocity fast. _____________________________
h. Many mitochondria and capillaries;
contraction velocity slow. _____________________________
i. Postural muscles; leg muscles.
_____________________________
61. Muscles increase in size by: (synthesis of new myofibril units/division
of muscle cells to form more cells/ or a combination of the first 2 methods).
______________________________________________
62. List 4 benefits of exercise affecting muscle tissue.
_____________________________
_____________________________
_____________________________
_____________________________
63. Muscles that are not used will decrease in size; this condition
is called _____________________.
64. List 10 differences between smooth and skeletal muscles.
____________________________
____________________________
____________________________
____________________________
____________________________
____________________________
____________________________
____________________________
____________________________
____________________________
65. Z-line counterparts in smooth muscle are dark-staining structures
called: __________________.
66. Smooth muscle cells lack refined myoneural jcts; these areas are
called: _____________________.
67. Smooth muscle cells are often arranged in sheets. The alternate
contractions of these sheets produces a movement called:
____________________________.
68. List 3 ways in which skeletal and smooth muscles are alike.
_____________________________
_____________________________
_____________________________
69. The main source of Ca++ for smooth muscle contraction is
from the: _____________________.
70. Smooth _______ (can/cannot) generate similar tensions to
skeletal muscle.
71. Smooth uses about _______ % the energy as skeletal muscle.
72. Name 2 neurotransmitters released at smooth muscle bulbous varicosities.
____________________________
____________________________
73. A smooth muscle contraction can be initiated by 3 mechanisms.
Name these mechanisms.
____________________________
____________________________
____________________________
74. Smooth muscle will contract vigorously in response to a stimulus,
but will then relax at a longer resting length. This phenomenon is
referred to as the: ____________________________.
75. Skeletal muscle functions best 30% below to 30% above its resting
length. Smooth muscle has a __________________ (wider/narrower) range.
76. Smooth muscle cells divide and increase in number, a characteristic
called:__________________.
The hormone ____________________ will cause this to occur.
77. Smooth muscle cells can make new cells, contractile proteins, and
elastin and collagen for surrounding connective tissues, a feature called:
_____________________________.
78. What kind of cell normally manufactures elastic and collagen fibers
for connective tissues?
_____________________________
79. Identify the kind of smooth muscle based on the descriptions given
below.
a. Most common.
_____________________________
b. Fibers structurally independent.
_____________________________
c. Large airways and large arteries;
arrector pili, internal eye muscles.
_____________________________
d. Cells arranged in sheets-united by
gap jcts. _____________________________
e. Contracts as unit and with rhythm.
_____________________________
f. Also called visceral muscle.
_____________________________
80. Explain the rationale (at the molecular level) behind stretching
and warming up before an athletic event. _______________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
81. What is the power stroke and how does it cause a muscle to shorten?
____________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
82. What is the difference between a graded response and a muscle twitch?
Use two graphs to explain your answer. ____________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
83. What is excitation-contraction coupling (i.e. events at the myoneural
junction)? Briefly summarize the steps involved._____________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
84. Organophosphate pesticides block the action of the enzyme AChE.
What symptoms would a person have if they are poisoned by these pesticides
and why?
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
85. Why does skeletal muscle have striations and smooth muscle does
not? __________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________