chapter 12- muscle Flashcards
(97 cards)
1
Q
During _____ muscle contraction causes the angle between two bones to decrease
A
flexion
2
Q
myosin ____
A
- makes up the thick filament of the sarcomere
- is a protein involved in muscle contraction
3
Q
What are the columns of muscle produced by the extension of the eqimplysium into the body of the muscle called?
A
-fascicles
4
Q
The _____ of a muscle is its attachment point on the relatively immobile bone
A
orgin
5
Q
when the muscles of you leg contract to move your lower leg back in order to kick a soccer ball, thus decreasing the angle between the femur and the tibia, the contraction produced is
A
flexion
6
Q
which of the following are characteristics of skeletal muscle
A
- striated
- multinucleate
7
Q
The contraction of smooth muscle cells:
A
- is graded dependents upon the concentration of calcium
- is slow and sustained
8
Q
In muscle ATP is used
A
- by myosin ATPase to break the bond between actin and myosin
- by myosin ATPase to energize the myosin cross bridge
- for calcium transport back to the sarcoplasmic reticulum
9
Q
when the biceps brachii of the arm contracts the angle bewteen the bones of the forearm and humerous decreases, what type of contraction is this?
A
flexion
10
Q
What type of muscle is multinucleate, with unbranched, striated fibers
A
skeletal muscle
11
Q
the site of attachment of a muscle to the bone that it moves it its _____
A
insertion
12
Q
what is the fibrous connective sheath that extends around the muscle?
A
epimysium
13
Q
the plasma membrane of a skeletal muscle is also called the ____
A
sarcolemma
14
Q
what is a muscle fiber
A
a skeletal muscle cell
15
Q
each fascicle is surrounded by a connective tissue sheath known as the ____
A
perimysium
16
Q
most stretch reflexes are examples of _____ feedback loops
A
negative
17
Q
When you do a chin up, the triceps brachil contract to help you lower down SLOWLY after the “up” position. the tricepts brachil are acting as _____
A
extensors
18
Q
While both ____ muscle in the heart and ____ muscle tissue in the blood vessels are capapble of initiating contraction on their own, ______ muscle
A
caridiac, smooth, skeletal
19
Q
In order for muscle contraction to occur, which of the following events must happen
A
- sarcoplasm calcium levels must increase
- ATP is hydrolyzed
20
Q
are types of skeletal muscle fibers
A
-fast twitch
- slow twitch
- type 2
- type 1
21
Q
A cell in skeletal muscle is also called a muscle _____
A
fiber
22
Q
The muscle ____ are columns of muscle tissue that are formed by the extension of the epimysium into the body of the muscle
A
fascicles
23
Q
which of the following change during contaction
A
- the I band gets smaller
- the H band gets smaller
24
Q
Fast oxidative of type IIA fibers
A
- are aerobic
- have a high myoglobin content
25
During sarcomere contraction the A band remains the same length while the ____ band and ______ band get shorter
I, H
26
A monosynaptic stretch reflex is an example of what type of feedback loop?
negative
27
The ______ is a fibrous connective tissue sheath that surrounds a whole muscle
epimysium
28
How does smooth muscle differ from skeletal muscle
- smooth muscle does not have sarcomeres
- the myosin in smooth muscle fibers is stacked perpendicular to the length of the cell
- the thin filaments in smooth muscle cells are much longer
29
What is occuring in the sarcomere at the indicated point on the muscle length-tension graph?
- the amount of tension produced will be at its minimum
| - the actin and myosin are overlapping and interfering with each other
30
When _______ ______ form between myosin and actin, they pull the actin towards the M line of the sarcomere
cross bridges
31
The pinkish tubelike structure labeled in the diagram is the ___ ______
transverse tubule
32
Which of the following influence the strength of contraction in a muscle
- thickness of muscle fiber
- initial resting length of fiber
- frequency of stimulation
- numbers of fibers stimulated
33
the area indicated by the arrow bracket shows the length of one
sarcomere
34
The calcium release channels themselves:
- are found in the sarcoplasmic reticulum
- release calcium in response in the shape of a vontage gated channel
-release calcium through passive diffusion
35
The calcium release channels themselves:
- are found in the sarcoplasmic reticulum
- release calcium in response in the shape of a vontage gated channel
- release calcium through passive diffusion
36
How is ATP used during muscle contraction?
- to energize the myosin heads and put them into position
- to fuel the pumps that move calcium back into the SR after contraction
- to break the bond between actin and myosin
37
creative phosphate:
is used to convert ADP into ATP
38
Within muscle fiber, what structure and releases calcium
terminal cisternae of the SR
39
When cardiac muscle cells are stimulated to conract the influx of ____ induces Ca2+ release
calcium
40
Increase the frequency of action potentials delivered to a muscle fiberso that the fiber does not relax and response adds together is called _____
summation
41
the light bands in skeletal muscle are also called ____ bands
I
42
Which of the following occur to gradually increase the force of a muscle contraction?
- increase the rate of motor unit stimulus
- recruit more motor units
- recruit larger motor units
43
What is the H band of the sarcomere
the area that contains only thick filaments
44
When a muscle experiences an increase in PO34 a decline in ATP a depleion of muscle glycogen and increased ADP in the sarcoplasm it experiences the phenomenon known as muscle _____
fatigue
45
what acts as levers to transfer the force of a muscles contraction
-bones
-joints
tendons
46
A reflex that passes the signal from the sensory neuron to the spinal interneuron to the alpha motor neuron is considered a(n) reflex
disynaptic
47
during ____ the fibers are stimulated to contract before they relax completely while ____ produces more force by increasing the number of fibers that are contracting
summation, recruitment
48
What are the series elastic components of muscle?
- tendond and connective tissue
| - elastic structures of muscle fibers
49
The contractions of skeletal muscles produce movements of bones at joints, the joints act as _____ to move the loads against which the muscle force is exereted
levers
50
During a(n) _____ contraction the tension that is produced by the muscle is not sufficient to move the load; consequently the mudcld does not contract
isometric
51
when a sarcomere contracts the ______ is pulled towards the M line sliding past or over the ____
actin, myosin
52
What makes up the thin filaments?
actin
53
each globular myosin head has binding sites for
actin and ATP
54
During moderate exercise, a muscle obtains energy from;
- plasma glucose
- triglycerides
- muslce glycogen
- free fatty acids
55
The elastic structures of muscle and tendons called the ____ _____ _____ must be pulled tight before a muscle contraction
series elastic component
56
The V02 max
- is usually 15-20% higher for males than females
- is estimated by the relationship of heart rate to oxygen
- is the maximal oxygen uptake or aerobic capacity
57
A motor neuron and all the muscle fibers that it innervates is called ____ ____
motor unit
58
The action of the Ca2+ ATPase pumps
- allows the fiber to relax
- moves calcium into the SR
- moves calcium against its gradient
59
______ Contractions are produced by varying the number of muscle fibers participating in the contraction
graded
60
when increasing numbers of motor units are activated, more force is generated. this is called
-motor unit recruitment
61
When a skeletal muscle experience a reduction in its ability to produce tension during exercise the muscle has undergone
fatigue
62
The aerobic capacity:
- is often expressed as the V02 max
- is the maximum rate of oxygen consumption
- is also called the maximal oxygen uptake
63
In muscle the high energy molecule ____ ____ or phosphocreatine donates a high energy phosphate group to recharge ATP
creatine phosphate
64
The power stroke:
- moves the actin towards the center of the sarcomere
- is produced by the myosin cross bridge
- generates the contractile force in the muscle cell
65
When ATP is added to a contracted muscle fiber, which of the following will occur
the muscle fiber can relax
66
Before actin and myosin can bind ________ binds to troponin C causing a conformational shape change that pulls tropomyosin off the F-actins active site
calcium
67
In order for a muscle to contract and shorten, the tension produced by the muscle must ____ the load on the muscle
be greater than
68
During an isotonic contraction:
- the tensions produced by the muscle is greater than the load
- the muscle shortens
69
As the load on the muscle increases, the velocity of shortening:
decreases
70
Which of the following are characterisitcs of single unit smooth muscle?
- many gap junctions
- display pacemaker activity
- respond to stretch
71
Which of the following are true cardiac muscle but not of skeletal muscle
- the entire myocardium contracts as a unit
| - signal to contract is passed between cells via gap junctions
72
In a(n) reflex, the sensory neuron detecting the change synapses only with the motor neuron that activates the muscle responding to the change
monosynaptic
73
The calcium release channels themselves:
- release calcium through passive diffusion
- are found in the sarcoplasmic reticulum
- release calcium in response to a change in the shape of a voltage gated channel
74
During the power stroke component of skeletal muscle contraction
the thin filament moves towards the M line
75
What type of contraction is produced when the tension created by the muscle is just greater than the load applied to the muscle?
isotonic contraction
76
The dark lines that can be seen in the middle of the I bands and the _____ which anchor the thin filaments
z disks
77
Where is most of the calcium stored in a relaxed muscle fiber?
terminal cisternae of SR
78
Skeletal muscles are attatched to bones via ____ which transfer the contractoin tension and allow for the movement of the bone
tendons
79
Within each muscle fiber densley packed subunits known as _____ extend in parallel rows from one end of the cell tothe other leaving no room between for other organelles
myofibrils
80
what is the function of troponin in muscle contraction?
to move/lever tropomyosin off the active sit of actin so that myosin can bind to it
81
What is the function of tropomyosin in muscle contraction
-to block myosin from binding to action where there is no contraction signal
82
What occurs in the muscle fiber during the latent period?
Ca++ is released
-AP travels along the transverse tubules
83
What is the muscle of muscle group called that acts on the same joint to produce the opposite contraction from the prime mover?
-Antagonist
84
The ___ ___ are produced by protein filaments located at the center of the thick filaments and serve to anchor the thick filaments thus helping stay
M liines
85
The transverse tubules or T- tubules;
- conduct action potentials
| - are formed from the sarcolemma
86
_____ reflexes maintain muscles at their optimal length
stretch
87
When a muscle contracts isometrically
- the load is greater than or equal to the tension that the muscle can produce
- the muscle does not shorten
88
Due to the lag time required by the cardiovascular system the skeletal muscle metabolize _____
anaerobically
89
analogies best explains how actin and myosin cycle within the cell?
the power strokes are asynchronous and attach alternately as in the actions in the actions of a team engaged in a tug or war
90
During muscle contraction:
that actin
91
During muscle contraction:
that actin and myosin overlap each other
92
A reflex arc that has one sensory neuron synapsing only with one motor neuron is called a(n) _____ reflex
monosynaptic
93
how is contraction initiated in cardiac muscle
A pacemaker region depolarizes
94
What is occuring in the sarcomere at the indicated point on the muscle length tension graph
- the amount of tension produced will be at its min
| - the actin and myosin are overlapping and interfering with each other
95
At what point will the velocity of shortening be the greatest?
when the load is zero
96
Which of the following statements about myosin are correct?
- each globular myosin head has a binding site for actin as well as for ATP
- the myosin heads act as myosin ATPse enzymes
- at rest, each globular myosin head is not attached to actin
97
In order for actin to bind to myosin, the active sites on the actin molecule must be uncovered. this involves the movement of tropomyosin by the protein
-troponin
